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19 Apr 2021 at 01:32
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Bibliography on: Corvids: Behavior


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RJR: Recommended Bibliography 19 Apr 2021 at 01:32 Created: 

Corvids: Behavior

Audubon Magazine: Members of the crow family, known as the corvids, are among the smartest birds in the world. Some are capable of using tools, playing tricks, teaching each other new things, even holding "funerals." And yet there's still much we don't know about these fascinating, sometimes confounding creatures. All corvids have relatively big brains for their size. But while a seed storer like a Pinyon Jay or a nutcracker has a huge hippocampus — a region involved in memory — crows and ravens are more like primates. They have exceptionally large forebrains, the domain of analytical thought, higher-level sensory processing, and flexible behavior.

Created with PubMed® Query: (behavior OR behaviour OR ethology) AND \(corvus[TIAB] OR corvid[TIAB] OR OR corvids[TIAB] OR corvidae[TIAB] OR crow[TIAB] OR crows[TIAB] OR raven[TIAB] OR ravens[TIAB] OR jay[TIAB] OR jays[TIAB] OR magpie[TIAB] OR magpies[TIAB] OR jackdaw[TIAB] OR jackdaws[TIAB]) NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2021-03-29

Pendergraft LT, Lehnert AL, JM Marzluff (2020)

Individual and social factors affecting the ability of American crows to solve and master a string pulling task.

Ethology : formerly Zeitschrift fur Tierpsychologie, 126(2):229-245.

Crows and other birds in the family Corvidae regularly share information to learn the identity and whereabouts of dangerous predators, but can they use social learning to solve a novel task for a food reward? Here we examined the factors affecting the ability of 27 wild-caught American crows to solve a common string-pulling task in a laboratory setting. We split crows into two groups; one group was given the task after repeatedly observing a conspecific model the solution, the other solved in the absence of conspecific models. We recorded the crows' estimated age, sex, size, body condition, level of nervousness, and brain volume using DICOM images from a CT scan. Although none of these variables were statistically significant, crows without a conspecific model and large brain volumes consistently mastered the task in the minimum number of days, whereas those with conspecific models and smaller brain volumes required varying and sometimes a substantial number of days to master the task. We found indirect evidence that body condition might also be important for motivating crows to solve the task. Crows with conspecific models were no more likely to initially solve the task than those working the puzzle without social information, but those that mastered the task usually copied the method most frequently demonstrated by their knowledgeable neighbors. These findings suggest that brain volume and possibly body condition may be factors in learning new tasks, and that crows can use social learning to refine their ability to obtain a novel food source, although they must initially learn to access it themselves.

RevDate: 2021-03-29
CmpDate: 2021-03-29

Armenteros JA, Caro J, SÁnchez-GarcÍa C, et al (2021)

Do non-target species visit feeders and water troughs targeting small game? A study from farmland Spain using camera-trapping.

Integrative zoology, 16(2):226-239.

Provision of food and water is a widespread tool implemented around the world for the benefit of game and other wildlife, but factors affecting the use of food and water by non-target species are poorly known. We evaluated visits to feeders and water troughs by non-game species using camera-traps in two separate areas of Spain. Feeders and water troughs were either "protected" (when surrounded by more than 50% of shrubs/forest) or "open" (in the opposite case). A total of 18 948 photos from 5344 camera-trapping days depicted animals, and 75 species were identified. Feeders and water troughs were visited by target species (partridges and lagomorphs, 55.3% of visits) and non-target species (44.7% of visits). Among the latter, corvids were the most common (46.1% of visits), followed by rodents (26.8%), other birds (23.6%, mainly passerines), columbids (1.9%), and other species at minor percentages. The highest proportion of visiting days to feeders and water troughs was from corvids (0.173) followed by other-birds (0.109) and rodents (0.083); the lowest proportion was recorded for columbids (0.016). Use intensity and visit frequency of water troughs tripled that recorded in feeders, and visits to open feeders/troughs were approximately twice those to protected ones. In summary: feeders and water troughs targeting small game species are also used regularly by non-target ones; they should be set close to cover to optimize their use by non-target species that are not competitors of target species (though corvids may visit them); water availability should be prioritized where drought periods are expected.

RevDate: 2021-03-23
CmpDate: 2021-03-23

Uomini N, Fairlie J, Gray RD, et al (2020)

Extended parenting and the evolution of cognition.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 375(1803):20190495.

Traditional attempts to understand the evolution of human cognition compare humans with other primates. This research showed that relative brain size covaries with cognitive skills, while adaptations that buffer the developmental and energetic costs of large brains (e.g. allomaternal care), and ecological or social benefits of cognitive abilities, are critical for their evolution. To understand the drivers of cognitive adaptations, it is profitable to consider distant lineages with convergently evolved cognitions. Here, we examine the facilitators of cognitive evolution in corvid birds, where some species display cultural learning, with an emphasis on family life. We propose that extended parenting (protracted parent-offspring association) is pivotal in the evolution of cognition: it combines critical life-history, social and ecological conditions allowing for the development and maintenance of cognitive skillsets that confer fitness benefits to individuals. This novel hypothesis complements the extended childhood idea by considering the parents' role in juvenile development. Using phylogenetic comparative analyses, we show that corvids have larger body sizes, longer development times, extended parenting and larger relative brain sizes than other passerines. Case studies from two corvid species with different ecologies and social systems highlight the critical role of life-history features on juveniles' cognitive development: extended parenting provides a safe haven, access to tolerant role models, reliable learning opportunities and food, resulting in higher survival. The benefits of extended juvenile learning periods, over evolutionary time, lead to selection for expanded cognitive skillsets. Similarly, in our ancestors, cooperative breeding and increased group sizes facilitated learning and teaching. Our analyses highlight the critical role of life-history, ecological and social factors that underlie both extended parenting and expanded cognitive skillsets. This article is part of the theme issue 'Life history and learning: how childhood, caregiving and old age shape cognition and culture in humans and other animals'.

RevDate: 2021-03-05

Kolkert HL, Smith R, Rader R, et al (2021)

Prey removal in cotton crops next to woodland reveals periodic diurnal and nocturnal invertebrate predation gradients from the crop edge by birds and bats.

Scientific reports, 11(1):5256.

Factors influencing the efficacy of insectivorous vertebrates in providing natural pest control services inside crops at increasing distances from the crop edge are poorly understood. We investigated the identity of vertebrate predators (birds and bats) and removal of sentinel prey (mealworms and beetles) from experimental feeding trays in cotton crops using prey removal trials, camera traps and observations. More prey was removed during the day than at night, but prey removal was variable at the crop edge and dependent on the month (reflecting crop growth and cover) and time of day. Overall, the predation of mealworms and beetles was 1-times and 13-times greater during the day than night, respectively, with predation on mealworms 3-5 times greater during the day than night at the crop edge compared to 95 m inside the crop. Camera traps identified many insectivorous birds and bats over crops near the feeding trays, but there was no evidence of bats or small passerines removing experimental prey. A predation gradient from the crop edge was evident, but only in some months. This corresponded to the foraging preferences of open-space generalist predators (magpies) in low crop cover versus the shrubby habitat preferred by small passerines, likely facilitating foraging away from the crop edge later in the season. Our results are in line with Optimal Foraging Theory and suggest that predators trade-off foraging behaviour with predation risk at different distances from the crop edge and levels of crop cover. Understanding the optimal farm configuration to support insectivorous bird and bat populations can assist farmers to make informed decisions regarding in-crop natural pest control and maximise the predation services provided by farm biodiversity.

RevDate: 2021-02-20

Rinnert P, A Nieder (2021)

Neural code of motor planning and execution during goal-directed movements in crows.

The Journal of neuroscience : the official journal of the Society for Neuroscience pii:JNEUROSCI.0739-20.2021 [Epub ahead of print].

The planning and execution of head-beak movements are vital components of bird behavior. They require integration of sensory input and internal processes with goal-directed motor output. Despite its relevance, the neurophysiological mechanisms underlying action planning and execution outside of the song system are largely unknown. We recorded single-neuron activity from the associative endbrain area Nidopallium caudolaterale (NCL) of two male carrion crows (Corvus corone) trained to plan and execute head-beak movements in a spatial delayed response task. The crows were instructed to plan an impending movement toward one of eight possible targets on the left or right side of a touchscreen. In a fraction of trials, the crows were prompted to plan a movement toward a self-chosen target. NCL neurons signaled the impending motion direction in instructed trials. Tuned neuronal activity during motor planning categorically represented the target side, but also specific target locations. As a marker of intentional movement preparation, neuronal activity reliably predicted both target side and specific target location when the crows were free to select a target. In addition, NCL neurons were tuned to specific target locations during movement execution. A subset of neurons was tuned during both planning and execution period; these neurons experienced a sharpening of spatial tuning with the transition from planning to execution. These results show that the avian NCL not only represents high-level sensory and cognitive task components, but also transforms behaviorally-relevant information into dynamic action plans and motor execution during the volitional perception-action cycle of birds.Significance StatementCorvid songbirds have become exciting new models for understanding complex cognitive behavior. As a key neural underpinning, the endbrain area Nidopallium caudolaterale (NCL) represents sensory and memory-related task components. How such representations are converted into goal-directed motor output remained unknown. In crows, we report that NCL neurons are involved in the planning and execution of goal-directed movements. NCL neurons prospectively signaled motion directions in instructed trials, but also when the crows were free to choose a target. NCL neurons showed a target-specific sharpening of tuning with the transition from the planning to the execution period. Thus, the avian NCL not only represents high-level sensory and cognitive task components, but also transforms relevant information into action plans and motor execution.

RevDate: 2021-02-19

Lozano-Ruiz A, Fasfous AF, Ibanez-Casas I, et al (2021)

Cultural Bias in Intelligence Assessment Using a Culture-Free Test in Moroccan Children.

Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists pii:6144703 [Epub ahead of print].

OBJECTIVE: Previous research has shown that cognitive tests can lead to misclassification when applying non-representative norms to measure cognitive performance. The objective of this study was to investigate whether this misclassification also occurs with a non-verbal so-called "culture-free" intelligence test administered to different age groups.

METHOD: The intelligence of a sample of healthy Moroccan children (N = 147) ages 7, 9, and 11 was assessed using the Coloured Raven's Progressive Matrices (CPM). Raw scores were used to study age differences, as well as misclassifications when applying the norms of three countries culturally different from Morocco (United Kingdom, Spain, and Oman).

RESULTS: Intelligence performance was not within the normal range when non-representative norms were applied to the Moroccan raw scores. Misclassifications accounted for a large percentage of the participants that supposedly displayed intelligence deficits, especially when applying the British norms. Up to 15.68% of the healthy children fell within the "intellectually impaired" range, and up to 62.5% fell "below average," with these percentages especially higher at older ages.

CONCLUSIONS: Our findings confirm that "culture-free" tests should be adapted to each culture and applied together with their culture's specific norms to prevent misclassification and allow for a better, unbiased neuropsychological assessment.

RevDate: 2021-02-01

Roelofs A (2021)

How attention controls naming: Lessons from Wundt 2.0.

Journal of experimental psychology. General pii:2021-13056-001 [Epub ahead of print].

When models of the attentional control of vocal naming, applied to color-word Stroop and picture-word interference, were first computationally implemented and examined in 1990, an implementable model proposed by Wundt (1880, 1902) was not considered. Although these modern computer models, and more recent ones, clarify many aspects of the interference, most models fail to explain its time course, as outlined in Roelofs (2003). Wundt's (1902) model assigns a key role to top-down inhibition, which is absent in most of the modern models. Here, an implementation of his model is presented, called Wundt 2.0. The necessity of perceptual inhibition was demonstrated by computer simulations of the interference and its time course, and supported by existing evidence from oscillatory brain activity in the alpha frequency band. Moreover, a new empirical study showed that Raven scores measuring the general intelligence factor g, discovered by Wundt's student Spearman (1904), predict the magnitude of the Stroop effect in fast errors, in line with the model and evidence on alpha band activity. Also, the study provided evidence that response inhibition is absent during vocal naming in the Stroop task. To conclude, Wundt's model has stood the test of time and provides a number of enduring lessons for our understanding of attention and performance. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

RevDate: 2021-01-27

Boone JD, Witt C, EM Ammon (2021)

Behavior-specific occurrence patterns of Pinyon Jays (Gymnorhinus cyanocephalus) in three Great Basin study areas and significance for pinyon-juniper woodland management.

PloS one, 16(1):e0237621 pii:PONE-D-20-21672.

The Pinyon Jay is a highly social, year-round inhabitant of pinyon-juniper and other coniferous woodlands in the western United States. Range-wide, Pinyon Jays have declined ~ 3-4% per year for at least the last half-century. Occurrence patterns and habitat use of Pinyon Jays have not been well characterized across much of the species' range, and obtaining this information is necessary for better understanding the causes of ongoing declines and determining useful conservation strategies. Additionally, it is important to better understand if and how targeted removal of pinyon-juniper woodland, a common and widespread vegetation management practice, affects Pinyon Jays. The goal of this study was to identify the characteristics of areas used by Pinyon Jays for several critical life history components in the Great Basin, which is home to nearly half of the species' global population, and to thereby facilitate the inclusion of Pinyon Jay conservation measures in the design of vegetation management projects. To accomplish this, we studied Pinyon Jays in three widely separated study areas using radio telemetry and direct observation and measured key attributes of their locations and a separate set of randomly-selected control sites using the U. S. Forest Service's Forest Inventory Analysis protocol. Data visualizations, principle components analysis, and logistic regressions of the resulting data indicated that Pinyon Jays used a distinct subset of available pinyon-juniper woodland habitat, and further suggested that Pinyon Jays used different but overlapping habitats for seed caching, foraging, and nesting. Caching was concentrated in low-elevation, relatively flat areas with low tree cover; foraging occurred at slightly higher elevations with generally moderate but variable tree cover; and nesting was concentrated in slightly higher areas with high tree and vegetation cover. All three of these Pinyon Jay behavior types were highly concentrated within the lower-elevation band of pinyon-juniper woodland close to the woodland-shrubland ecotone. Woodland removal projects in the Great Basin are often concentrated in these same areas, so it is potentially important to incorporate conservation measures informed by Pinyon Jay occurrence patterns into existing woodland management paradigms, protocols, and practices.

RevDate: 2021-01-26
CmpDate: 2021-01-26

Themelin M, Ribic CA, Melillo-Sweeting K, et al (2020)

A new approach to the study of relationship quality in dolphins: Framework and preliminary results.

Behavioural processes, 181:104260.

Proximity and synchronous behaviours from surface observations have been used to measure association patterns within and between dolphin dyads. To facilitate an investigation of relationship quality in dolphins, we applied a method used for primates and ravens that examined three main components to describe relationships: value, security, and compatibility. Using pilot data from long-term research of two study populations for this preliminary assessment, these three components were extracted from PCA of eight behavioural variables with more than 80 % variance accounted for in both study groups. Only pair swim position differed between groups. Although value, security, and compatibility are abstract terms, each is based on behaviours identified as important in dolphin social life, at least for these two populations. Examining relationship quality in dolphins with a method used to illustrate dyadic differences for primates and ravens allows for a quantitative, comparative assessment of sociality across disparate taxa. Although these species are diverse in their anatomies and in their social habitats (e.g., aquatic, terrestrial, aerial), they may well share the basic societal building blocks in the factors affecting how relationships are formed. We discuss how an examination of these behavioural variables facilitates understanding relationship quality in dolphins, as well as how dolphin relationships fit into the context of social animals' society.

RevDate: 2021-01-14

Rial-Berriel C, Acosta-Dacal A, Cabrera Pérez MÁ, et al (2020)

Intensive livestock farming as a major determinant of the exposure to anticoagulant rodenticides in raptors of the Canary Islands (Spain).

The Science of the total environment, 768:144386 pii:S0048-9697(20)37917-1 [Epub ahead of print].

The Canary Islands (Spain) is a biodiversity hotspot, with more than 4500 registered endemic species. However, it is subject to high anthropogenic pressure that threatens its wildlife in various ways. In the context of forensic toxicological surveys, the presence of anticoagulant rodenticides (AR) has been investigated in the liver of 831 animal carcasses with georeferenced data from 2011 to May 2020. The high concentrations of toxic pesticides in carcasses and in baits found close to the corpses indicated that all the reptiles and most of the mammals tested positive for AR were intentionally poisoned, although mainly by other substances. The frequency of detection of AR in non-raptor birds (n = 343) was only 4.1%, being the Canary raven the most frequently affected species (7/97, 7.2%). On the contrary, in raptors (n = 308) the detection frequency was almost 60%, with an average of more than 2 ARs per animal. The highest concentrations were found in the common kestrel. We present for the first-time results of AR contamination in two species of raptors that are very rare in Europe, Eleonora's falcon (n = 4) and Barbary falcon (n = 13). The temporal trend of positive cases remains stable, but since the entry into force of the restriction to the concentration of the active ingredient in baits (<30 ppm), a decrease in the concentrations of these compounds in the raptors' liver has been detected. Conversely, we registered an increase in the number of ARs per animal. From the study of the geographic information system (GIS) it can be deduced that intensive livestock farms are an important determinant in the exposure of raptors to ARs. Those birds that have their territory near intensive production farms have higher levels of exposure than those of birds that live far from such facilities.

RevDate: 2021-01-14

Tornick J, B Gibson (2021)

Clark's nutcrackers (Nucifraga columbiana) use a visual barrier for cache protection.

Journal of comparative psychology (Washington, D.C. : 1983) pii:2021-07054-001 [Epub ahead of print].

Previous work with corvids such as scrub jays (Aphelocoma californica) and ravens (Corvus corax) suggests that many social corvids alter their caching behavior when observed by conspecifics to protect their caches. We examined whether the Clark's nutcracker (Nucifraga columbiana), an asocial corvid, can utilize a barrier to conceal its caching activities from a conspecific observer. Nutcrackers were allowed to cache nuts in a visible or concealed location in either the presence or absence of an observer. Nutcrackers were also given experience of having their caches pilfered. The nutcrackers cached significantly more nuts in the concealed compared to a visible location when observed. Importantly, nutcrackers also recovered a larger percentage of their nuts 24 hr later from a visible cache location but when the observer was no longer present. The results extend recent work suggesting that relatively nonsocial corvids, similar to their more social relatives, also engage in multiple forms of cache protection. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

RevDate: 2021-01-13

Zhang Y, Yu C, Chen L, et al (2021)

Performance of Azure-winged magpies in Aesop's fable paradigm.

Scientific reports, 11(1):804.

In this study, the improved Aesop's fable paradigm-a series of experiments originally used to test whether some animals understand the causality associated with water replacement-was used to explore the cognitive ability of Azure-winged magpies (Cyanopica cyanus). Experimental results on causal cue tasks showed that the Azure-winged magpies prefer water-filled tubes over sand-filled tubes, heavy objects over light objects, and solid objects over hollow objects. However, they failed to notice the diameter and water level of the tubes. They also failed to pass the counterintuitive U-shaped tube task in arbitrary cue tasks. Our results demonstrated that Azure-winged magpies have a certain cognitive ability but not an understanding of causality, a characteristic comparable to that of other corvids. Moreover, Azure-winged magpies exhibited the ability of training transfer and analogical problem solving from the perspective of cognitive psychology. We believe that object-bias has little effect on Azure-winged magpies in this study. We can conclude that the Azure-winged magpies partially completed the tasks by trial-and-error learning.

RevDate: 2021-01-09

Wenig K, Boucherie PH, T Bugnyar (2021)

Early evidence for emotional play contagion in juvenile ravens.

Animal cognition [Epub ahead of print].

Perceiving, evaluating and reacting towards conspecifics' emotional states are important challenges of social group living. Emotional contagion describes an alignment of emotional states between individuals and is widely believed to be based on behavioral synchronization, i.e., behavioral contagion. As basic empathy-like processes, the occurrence of both forms of contagion seems to underlie early ontogenetic trajectories in humans and non-human species. In the present study, we assessed play as a context for studying the development of emotional contagion and its interlink with behavioral contagion in ten juvenile common ravens. Ravens are exceptional players that engage in all three forms of play: object, locomotion and social play. To assess potential ontogenetic patterns of both behavioral and emotional contagion, we tested juvenile ravens at two different periods of early development, at three- and six-month post-hatching. We elicited object play in one or several ravens (demonstrators) in a standardized experimental environment, using a playground setup. At both test ages, we found evidence for emotional contagion as observer ravens showed an increase of locomotion and social play after we provided the demonstrator(s) with the playground setup, but no significant changes in the amount of object play. Hence, observers did not copy motor patterns from demonstrator(s) but engaged in other forms of play. Our findings speak for a transfer of a general mood state in the context of play in ravens as young as 3 months and against behavioral mimicry as a precondition for emotional contagion.

RevDate: 2021-01-09

Gallego-Abenza M, Blum CR, T Bugnyar (2021)

Who is crying wolf? Seasonal effect on antipredator response to age-specific alarm calls in common ravens, Corvus corax.

Learning & behavior [Epub ahead of print].

Communication about threats including those posed by the presence of predators occurs mainly through acoustic signals called alarm calls. The comprehension of these calls by receivers and their rapid antipredator response are crucial in terms of survival. However, to avoid overreaction, individuals should evaluate whether or not an antipredator response is needed by paying attention to who is calling. For instance, we could expect adults to be more experienced with predator encounters than juveniles and thus elicit stronger antipredator responses in others when alarming. Similarly, we could expect a stronger response to alarm calls when more than one individual is calling. To test these assumptions, we applied a playback experiment to wild ravens, in which we manipulated the age class (adult or juvenile) and the number (one or two) of the callers. Our results revealed a seasonal effect of age class but no effect of number of callers. Specifically, the ravens responded with stronger antipredator behaviour (vigilance posture) towards alarm calls from adults as compared to juveniles in summer and autumn, but not in spring. We discuss alternative interpretations for this unexpected seasonal pattern and argue for more studies on call-based communication in birds to understand what type of information is relevant under which conditions.

RevDate: 2021-01-04
CmpDate: 2021-01-04

Boeckle M, Schiestl M, Frohnwieser A, et al (2020)

New Caledonian crows plan for specific future tool use.

Proceedings. Biological sciences, 287(1938):20201490.

The ability to plan for future events is one of the defining features of human intelligence. Whether non-human animals can plan for specific future situations remains contentious: despite a sustained research effort over the last two decades, there is still no consensus on this question. Here, we show that New Caledonian crows can use tools to plan for specific future events. Crows learned a temporal sequence where they were (a) shown a baited apparatus, (b) 5 min later given a choice of five objects and (c) 10 min later given access to the apparatus. At test, these crows were presented with one of two tool-apparatus combinations. For each combination, the crows chose the right tool for the right future task, while ignoring previously useful tools and a low-value food item. This study establishes that planning for specific future tool use can evolve via convergent evolution, given that corvids and humans shared a common ancestor over 300 million years ago, and offers a route to mapping the planning capacities of animals.

RevDate: 2020-12-28
CmpDate: 2020-12-28

Wu T, Shen H, Sheng Y, et al (2020)

Use of cognitive correction training improves learning for children with mathematics learning disability.

Applied neuropsychology. Child, 9(2):172-178.

Children with normal intelligence may experience varying degrees of mathematics learning disabilities (MD). This study aims to conduct training to improve the brain's cognitive ability for mathematics learning by focusing on two important mathematical cognitive abilities. This was a prospective study of 70 children in grades 2-5 from two primary schools in Changzhou and with MD enrolled from June 2015 to February 2017. The children were randomized 1:1 to the training and control groups. A training cycle included 40 sessions (5/weeks) (30 min each session). The efficacy of learning was assessed by assessing number learning and graph reasoning, and by using the Raven standard reasoning test score. In the training group, backward number memory (from 6.1 ± 1.8 to 6.7 ± 1.3, P = 0.02), number sequential connection (from 54.4 ± 14.5 to 47.1 ± 12.1, P < 0.01), and rapid graph judgment (from 531.9 ± 76.3 to 557.8 ± 85.7, P = 0.04) were improved by training, while there was no effect on forward number memory (P = 0.13). There were significant differences in total score and scores of b, c, and e series before and after training (all P < 0.05). The children in the control group had no improvement after 8 weeks. There was a correlation between the ability of rapid graphic judgment before and after training and the score of the Raven E series (r = 0.384, P = 0.024), and between the score of the Raven C series and the score of the Raven D series (r = 0.468, P = 0.013). Cognitive correction training improved the sensitivity to numbers and mathematics learning in children with MD.

RevDate: 2020-12-22
CmpDate: 2020-12-22

Mohamed Benkada A, Pontier F, V Dufour (2020)

Conflict management in rooks (Corvus frugilegus): Victims do not display post-conflict affiliation but avoid their former aggressor.

Behavioural processes, 179:104198.

Many social species use post-conflict behaviors to mitigate the consequences of conflicts. One of these behaviors is the victim's affiliation with its former opponent following conflict in an attempt to restore the damaged relationship. The victim can also affiliate with a third party. Affiliation with former opponents and third parties also alleviates stress. Studies of conflict management strategies in birds mostly concern corvids, and more specifically rooks (Corvus frugilegus). In this colonial pair-bonded species, the most valuable relationship is with the mate. It is rarely conflictual, meaning that there is generally no need for any post-conflict affiliation. However, conflicts occur with other social partners, and victims may primarily use third-party affiliation to avoid renewed aggression after conflicts. Previous studies of rooks failed to show a protective role of third-party affiliations for rook victims. The present study seeks to further investigate the use and efficiency of these conflict management strategies from the victim's perspective. We recorded conflicts and post-conflict behaviors in captive rooks using the standard post-conflict matched control comparison method. Victims did not affiliate with their former opponent or with third parties after conflict, but rather avoided their former aggressor, thus successfully limiting the risk of renewed aggression. Post-conflict affiliations are not observed in all rook colonies, suggesting that avoidance of the former aggressor may be a more commonly used strategy than previously thought.

RevDate: 2020-12-16

Kaplan G (2020)

Of Great Apes and Magpies: Initiations into Animal Behaviour.

Animals : an open access journal from MDPI, 10(12): pii:ani10122369.

This paper presents three case studies of exceptional human encounters with animals. These particular examples were selected because they enabled analysis of the underlying reasons that led the human participants to respond in new ways to their animal counterparts. The question asked here is whether sudden insights into the needs and abilities of an animal arises purely from an anthropocentric position as empathy because of genetic closeness (e.g., chimpanzees) or is something else and whether new insights can be applied to other phylogenetic orders not close to us, e.g., birds, and change research questions and implicit prejudices and stereotypes. Particularly in avian species, phylogenetically distant from humans, the prejudices (anthroprocentric position) and the belief in human uniqueness (human exceptionalism) might be greater than in the reactions to primates. Interestingly, in studies of great apes, contradictory opinions and controversies about cognitive abilities, especially when compared with humans, tend to be pronounced. Species appropriateness in test designs are desirable present and future goals but here it is suggested how different experiences can also lead to different questions that explode the myth of human uniqueness and then arrive at entirely different and new results in cognitive and affective abilities of the species under investigation.

RevDate: 2020-12-15
CmpDate: 2020-12-15

Mori A, R Bertani (2020)

Revision and cladistic analysis of Psalistops Simon, 1889, Trichopelma Simon, 1888 and Cyrtogrammomma Pocock, 1895 (Araneae: Theraphosidae) based on a cladistic analysis of relationships of Theraphosidae, Barychelidae and Paratropididae.

Zootaxa, 4873(1):zootaxa.4873.1.1 pii:zootaxa.4873.1.1.

The genera Psalistops Simon, 1889, Trichopelma, Simon, 1888 and Cyrtogrammomma Pocock, 1895 are revised and included in cladistics analyses including almost all species of these genera. In order to test previous morphological hypotheses on the relationships of Barychelidae, Paratropididae and Theraphosidae and because of the controversial taxonomic position of Psalistops and Trichopelma, a set of terminal taxa representing all subfamilies of Paratropididae (Paratropidinae, Glabropelmatinae), Barychelidae (Barychelinae, Sasoninae, Trichopelmatinae) and most theraphosid subfamilies were included, as well as a diplurid, a nemesiid, and a pycnothelid, the later used to root the cladogram. The matrix with 66 terminal taxa, 2 continuous and 93 discrete characters was analysed with TNT 1.5. We found that Trichopelmatinae is not a monophyletic group, and Psalistops is transferred to Theraphosidae, as well as the barychelid genus Cyrtogrammomma and the paratropidid genus Melloina Brignoli. Cyrtogrammomma was retrieved as the sister group of Trichopelma, and Melloina as the sister group of Holothele Karsch. Psalistops was retrieved as the sister group of Reichlingia Rudloff, and the clade with these two genera is the most basal in Theraphosidae. Barychelidae was found to be monophyletic and the sister group of Theraphosidae. Paratropididae was retrieved as the sister group of Barychelidae + Theraphosidae. The relationship and possible synapomorphies of the three families are herein discussed. This is the first time since Raven (1985) that representatives of all barychelid (Barychelinae, Sasoninae, Trichopelmatinae), paratropidid (Paratropidinae, Glabropelmatinae) and most theraphosid subfamilies have been included in a morphological cladistic analysis. Psalistops comprises two species, P. melanopygius Simon, 1889 (type species) and P. colombianus sp. nov. Psalistops montigena Simon, 1889, P. tigrinus Simon, 1889 and P. zonatus Simon, 1889 are synonymized with P. melanopygius Simon, 1889. Psalistops fulvus Bryant, 1948, P. hispaniolensis Wunderlich, 1988 (fossil), P. maculosus Bryant, 1948, P. venadensis Valerio, 1986 and P. steini (Simon, 1889) are transferred to Trichopelma. Psalistops gasci Maréchal, 1996 is transferred to Hapalopus Ausserer (Theraphosidae); P. opifex (Simon, 1889) and P. solitarius (Simon, 1889) are transferred to Schismatothele Karsch, 1879 (Theraphosidae). Schismatothele solitarius (Simon, 1889) n. comb. is synonymized with Schismatothele lineata Karsch, 1879, n. syn. Psalistops nigrifemuratus Mello-Leitão, 1939 is probably a nemesiid or pycnothelid, and herein considered as nomen dubium in Pycnothelidae. Trichopelma comprises 22 species: Trichopelma nitidum Simon, 1888 (type species), T. coenobita (Simon, 1889), T. steini (Simon, 1889), T. affine (Simon, 1892), T. cubanum (Simon, 1903), T. maculatum (Banks, 1906), T. zebra (Petrunkevitch, 1925), T. banksia Özdikmen Demir, 2012, T. insulanum (Petrunkevitch, 1926), T. fulvus (Bryant, 1948) n. comb., T. laselva Valerio, 1986, T. venadensis (Valerio, 1986) n. comb., T. huffi sp. nov., T. gabrieli sp. nov., T. tostoi sp. nov., T. goloboffi sp. nov., T. juventud sp. nov., T. laurae sp. nov., T.bimini sp. nov., T. loui sp. nov., T. platnicki sp. nov., and T. hispaniolensis Wunderlich, 1988 n. comb. (fossil). Trichopelma maculosus (Bryant, 1948) n. comb. is synonymized with P. fulvus Bryant, 1948; T. corozalis (Petrunkevitch, 1929) is synonymized with T. insulanum (Petrunkevitch, 1926). Trichopelma astutum Simon, 1889 is transferred to Euthycaelus Simon, 1889, and T. maddeni Esposito Agnarsson, 2014 to Holothele Karsch, 1879 (Theraphosidae). Trichopelma flavicomum Simon, 1891 is transferred to Neodiplothele (Barychelidae, Sasoninae). The species T. illetabile Simon, 1888, T. spinosum (Franganillo, 1926), T. scopulatum (Fischel, 1927) and T. eucubanum Özdikmen Demir, 2012 are considered as nomina dubia. Cyrtogrammomma comprises two species: C. monticola Pocock, 1895 (type species) and C. raveni sp. nov.

RevDate: 2020-12-14
CmpDate: 2020-12-14

Lin Y, Zhang X, Huang Q, et al (2020)

The Prevalence of Dyslexia in Primary School Children and Their Chinese Literacy Assessment in Shantou, China.

International journal of environmental research and public health, 17(19):.

The epidemiological studies of Chinese developmental dyslexia (DD) in China are still limited. In addition, literacy assessment has seldom been performed for children with dyslexia, due to lack of uniform assessment tools. This study was aimed at investigating the prevalence rate of children with dyslexia, and to evaluate their Chinese reading ability. A total of 2955 students aged 7-12 years were enrolled by randomized cluster sampling. The study was divided into three stages. In stage I, all participating students were asked to finish the Combined Raven Test (CRT) and Chinese Vocabulary Test and Assessment Scale. In stage II, the Chinese teachers and parents of the children with suspected dyslexia were interviewed by psychiatrists, and finished the Dyslexia Checklist for Chinese Children (DCCC). In stage III, these children were evaluated by child psychiatrists for the diagnosis with or without dyslexia, according to the fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-5), and their Chinese literacy was further evaluated by using the Chinese Reading Ability Test (CRAT). The prevalence rate of children with dyslexia was 5.4% in Shantou city, 8.4% in boys and 2.3% in girls, with a gender ratio of 3.7:1.0. Children with dyslexia scored lower in all the five subscales of the CRAT tests. including phonological awareness, morphological awareness, rapid automatized naming, orthographic awareness, and reading ability than the control group (all p < 0.001). This study suggested that the prevalence rate of Chinese dyslexia in Shantou city is roughly equivalent to that previously reported in China. Children with dyslexia have a relatively lower Chinese reading ability in all assessments.

RevDate: 2020-12-14
CmpDate: 2020-12-04

Zhao W, Li H, Zhu X, et al (2020)

Effect of Birdsong Soundscape on Perceived Restorativeness in an Urban Park.

International journal of environmental research and public health, 17(16):.

Natural soundscapes have beneficial effects on the perceived restorativeness of an environment. This study examines the effect of birdsong, a common natural soundscape, on perceived restorativeness in Harbin Sun Island Park in China. Eight sites were selected and a series of questionnaire surveys on perceived restorativeness soundscape scale (PRSS) of four birdsong types were conducted during summer and winter. Two-hundred and forty respondents participated in this survey. Analysis of the survey results shows that different types of birdsong have different perceived restorativeness effects in different seasons. Crow birdsong has the worst effect on the perceived restorativeness in both summer and winter. Moreover, sound comfort and preference are significantly associated with the perceived restorativeness. The perceived restorativeness soundscape is best when birdsong is at a height of 4 m rather than 0.5 m or 2 m. The demographic/social factors of age, education, and stress level are all correlated with perceived restorativeness. There are suggestions for urban park design, especially with constructed natural elements. Creating a suitable habitat for multiple species of birds will improve perceived restorativeness. Moreover, appropriate activities should be provided in city parks to ensure restorativeness environments, especially for subjects with high levels of education and stress.

RevDate: 2020-12-14
CmpDate: 2020-12-04

Fongaro E, J Rose (2020)

Crows control working memory before and after stimulus encoding.

Scientific reports, 10(1):3253.

The capacity of working memory is limited and this limit is comparable in crows and primates. To maximize this resource, humans use attention to select only relevant information for maintenance. Interestingly, attention-cues are effective not only before but also after the presentation of to-be-remembered stimuli, highlighting control mechanisms beyond sensory selection. Here we explore if crows are also capable of these forms of control over working memory. Two crows (Corvus corone) were trained to memorize two, four or six visual stimuli. Comparable to our previous results, the crows showed a decrease in performance with increasing working memory load. Using attention cues, we indicated the critical stimulus on a given trial. These cues were either presented before (pre-cue) or after sample-presentation (retro-cue). On other trials no cue was given as to which stimulus was critical. We found that both pre- and retro-cues enhance the performance of the birds. These results show that crows, like humans, can utilize attention to select relevant stimuli for maintenance in working memory. Importantly, crows can also utilize cues to make the most of their working memory capacity even after the stimuli are already held in working memory. This strongly implies that crows can engage in efficient control over working memory.

RevDate: 2020-12-14
CmpDate: 2020-12-04

Lee VE, McIvor GE, A Thornton (2019)

Testing relationship recognition in wild jackdaws (Corvus monedula).

Scientific reports, 9(1):6710 pii:10.1038/s41598-019-43247-x.

According to the social intelligence hypothesis, understanding the challenges faced by social animals is key to understanding the evolution of cognition. In structured social groups, recognising the relationships of others is often important for predicting the outcomes of interactions. Third-party relationship recognition has been widely investigated in primates, but studies of other species are limited. Furthermore, few studies test for third-party relationship recognition in the wild, where cognitive abilities are deployed in response to natural socio-ecological pressures. Here, we used playback experiments to investigate whether wild jackdaws (Corvus monedula) track changes in their own relationships and the relationships of others. Females were presented with 'infidelity simulations': playbacks of their male partner copulating with a neighbouring female, and their male neighbour copulating with another female, against a congruent control. Our results showed substantial inter-individual variation in responses, but females did not respond more strongly to infidelity playbacks, indicating that jackdaws may not attend and/or respond to relationship information in this experimental context. Our results highlight the need for further study of relationship recognition and other cognitive traits that facilitate group-living in the wild, particularly in non-primates and in a wider range of social systems.

RevDate: 2020-12-11

Dussex N, Kutschera VE, Wiberg RAW, et al (2020)

A genome-wide investigation of adaptive signatures in protein-coding genes related to tool behaviour in New Caledonian and Hawaiian crows.

Molecular ecology [Epub ahead of print].

Very few animals habitually manufacture and use tools. It has been suggested that advanced tool behaviour co-evolves with a suite of behavioural, morphological and life-history traits. In fact, there are indications for such an adaptive complex in tool-using crows (genus Corvus species). Here, we sequenced the genomes of two habitually tool-using and ten non-tool-using crow species to search for genomic signatures associated with a tool-using lifestyle. Using comparative genomic and population genetic approaches, we screened for signals of selection in protein-coding genes in the tool-using New Caledonian and Hawaiian crows. While we detected signals of recent selection in New Caledonian crows near genes associated with bill morphology, our data indicate that genetic changes in these two lineages are surprisingly subtle, with little evidence at present for convergence. We explore the biological explanations for these findings, such as the relative roles of gene regulation and protein-coding changes, as well as the possibility that statistical power to detect selection in recently diverged lineages may have been insufficient. Our study contributes to a growing body of literature aiming to decipher the genetic basis of recently evolved complex behaviour.

RevDate: 2020-12-03

Vernouillet A, Casidsid HJM, DM Kelly (2020)

Conspecific presence, but not pilferage, influences pinyon jays' (Gymnorhinus cyanocephalus) caching behavior.

Learning & behavior pii:10.3758/s13420-020-00450-5 [Epub ahead of print].

Caching species store food when plentiful to ensure availability when resources are scarce. These stores may be at risk of pilferage by others present at the time of caching. Cachers may reduce the risk of loss by using information from the social environment to engage in behaviors to secure the resource-cache protection strategies. Here, we examined whether pinyon jays, a highly social corvid, use information from the social environment to modify their caching behavior. Pinyon jays were provided with pine seeds to cache in two visually distinct trays. The cacher could be observed by a non-pilfering conspecific, a pilfering conspecific, or an inanimate heterospecific located in an adjoining cage compartment, or the cacher could be alone. After caching, the pilfered tray was placed in the adjoining compartment where caches were either pilfered (pilfering conspecific and inanimate heterospecific conditions) or remained intact (non-pilfering conspecific and alone conditions). The safe tray was placed in a visible, but inaccessible, location. Overall, pinyon jays reduced the number of pine seeds cached in the pilfered tray when observed, compared with caching alone. However, their caching behavior did not differ between the pilfering conspecific and the non-pilfering conspecific conditions. These results suggest that either pinyon jays were unable to discriminate between the pilfering and non-pilfering conspecifics, or they generalized their experience of risk from the pilfering conspecific to the non-pilfering conspecific. Thus, we report evidence that pinyon jays use cache protection strategies to secure their resources when observed, but respond similarly when observed by pilfering and non-pilfering conspecifics.

RevDate: 2020-11-23

Wagener L, A Nieder (2020)

Categorical Auditory Working Memory in Crows.

iScience, 23(11):101737 pii:S2589-0042(20)30934-2.

The ability to group sensory data into behaviorally meaningful classes and to maintain these perceptual categories active in working memory is key to intelligent behavior. Here, we show that carrion crows, highly vocal and cognitively advanced corvid songbirds, possess categorical auditory working memory. The crows were trained in a delayed match-to-category task that required them to flexibly match remembered sounds based on the upward or downward shift of the sounds' frequency modulation. After training, the crows instantaneously classified novel sounds into the correct auditory categories. The crows showed sharp category boundaries as a function of the relative frequency interval of the modulation. In addition, the crows generalized frequency-modulated sounds within a category and correctly classified novel sounds kept in working memory irrespective of other acoustic features of the sound. This suggests that crows can form and actively memorize auditory perceptual categories in the service of cognitive control of their goal-directed behaviors.

RevDate: 2020-11-23
CmpDate: 2020-11-23

Nieder A, R Mooney (2020)

The neurobiology of innate, volitional and learned vocalizations in mammals and birds.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 375(1789):20190054.

Vocalization is an ancient vertebrate trait essential to many forms of communication, ranging from courtship calls to free verse. Vocalizations may be entirely innate and evoked by sexual cues or emotional state, as with many types of calls made in primates, rodents and birds; volitional, as with innate calls that, following extensive training, can be evoked by arbitrary sensory cues in non-human primates and corvid songbirds; or learned, acoustically flexible and complex, as with human speech and the courtship songs of oscine songbirds. This review compares and contrasts the neural mechanisms underlying innate, volitional and learned vocalizations, with an emphasis on functional studies in primates, rodents and songbirds. This comparison reveals both highly conserved and convergent mechanisms of vocal production in these different groups, despite their often vast phylogenetic separation. This similarity of central mechanisms for different forms of vocal production presents experimentalists with useful avenues for gaining detailed mechanistic insight into how vocalizations are employed for social and sexual signalling, and how they can be modified through experience to yield new vocal repertoires customized to the individual's social group. This article is part of the theme issue 'What can animal communication teach us about human language?'

RevDate: 2020-11-20
CmpDate: 2020-11-20

Segura A, Jimenez J, P Acevedo (2020)

Predation of young tortoises by ravens: the effect of habitat structure on tortoise detectability and abundance.

Scientific reports, 10(1):1874.

The predation of young tortoise is considered a major cause of mortality for many tortoise species. The predation by common ravens has been identified as being responsible for significant decreases in tortoise populations. Mediterranean spur-thighed tortoise hatchlings and juveniles in Maamora forest (Morocco) were studied in order to describe the size/age class predation of common ravens on young tortoises and infer the drivers of predation risk and population abundance. The results showed a high level of predation on young tortoises (<75 mm carapace length) attributed to ravens in areas with low vegetation cover, representing 100% of the cases of mortality (n = 147), but it was moderate in covered areas (n = 19), representing 12-27%. The population structure of living juveniles differed significantly between covered and uncovered areas, thus suggesting that raven predation might modify juvenile population structure. Finally, N-mixture models showed a positive relationship between (i) bare cover and tortoise detectability that is only evidenced when the plot is far from a perch and (ii) population abundance and shrub species-richness, being higher in uncovered areas. Our results improve the knowledge on predation and survival on this critical stage in life, which is crucial for the conservation of the Mediterranean spur-thighed tortoise.

RevDate: 2020-11-16

Blum CR, Fitch WT, T Bugnyar (2020)

Rapid Learning and Long-Term Memory for Dangerous Humans in Ravens (Corvus corax).

Frontiers in psychology, 11:581794.

Like many predatory species, humans have pronounced individual differences in their interactions with potential prey: some humans pose a lethal threat while others may provide valuable resources. Recognizing individual humans would thus allow prey species to maximize potential rewards while ensuring survival. Previous studies on corvids showed they can recognize and remember individual humans. For instance, wild American crows produced alarm calls toward specifically masked humans up to 2.7 years after those humans had caught and ringed them while wearing that mask. However, individual behavior of the crows or the impact of social features on their responses, was hardly examined. Here, we studied predator learning and social effects on responses, using a similar method, in captive common ravens (Corvus corax). We investigated learning and the impact of key social components on individual reactions to artificial predators. Human experimenters wore two types of masks while walking past two raven aviaries. In four training trials, the "dangerous" mask was presented while carrying a dead raven, whereas the "neutral" mask was presented empty-handed. Between every training trial and in all following trials, we presented both masks without dead ravens. We assessed the subjects' (i) learning speed, (ii) selective long-term response, and (iii) potential effects of social dynamics on individual alarm calling frequency. Ravens learned quickly (often based on the first trial), and some individuals distinguished the dangerous from the neutral mask for the next 4 years. Despite having received the same amount and quality of exposure to the dangerous mask, we found pronounced individual differences in alarm calling that were fairly consistent across test trials in socially stable situations: dominance, but not sex explained individual differences in alarm responses, indicating the potential use of alarm calls as "status symbols." These findings fit to those in wild bird populations and dominant individuals signaling their quality. Changes in the individuals' participation and intensity of alarm calling coincided with changes in group composition and pair formation, further supporting the role of social context on ravens' alarm calling.

RevDate: 2020-11-07

Shahhosseini N, Frederick C, Racine T, et al (2020)

Modeling Host-Feeding Preference and Molecular Systematics of Mosquitoes in Different Ecological Niches in Canada.

Acta tropica pii:S0001-706X(20)31647-8 [Epub ahead of print].

Several mosquito-borne viruses (mobovirus) cause infections in Canada. Ecological data on mosquito species and host range in Canada remains elusive. The main aim of the current study is to determine the host range and molecular systematics of mosquito species in Canada. Mosquitoes were collected using BG-Sentinel traps and aspirators at 10 trapping sites in Canada during 2018 and 2019. Mosquitoes collected were identified via morphology and molecular techniques. Mosquito sequences were aligned by MUSCLE algorithm and evolutionary systematics were drawn using MEGA and SDT software. Moreover, the source of blood meals was identified using a DNA barcoding technique. A total of 5,708 female mosquitoes over 34 different taxa were collected. DNA barcodes and evolutionary tree analysis confirmed the identification of mosquito species in Canada. Of the total collected samples, 201 specimens were blood-fed female mosquitoes in 20 different taxa. Four mosquito species represented about half (51.47%) of all collected blood-fed specimens: Aede cinereus (39 specimens, 19.11%), Aedes triseriatus (23, 11.27%), Culex pipiens (22, 10.78%), and Anopheles punctipennis (21, 10.29%). The most common blood meal sources were humans (49 mosquito specimens, 24% of all blood-fed mosquito specimen), pigs (44, 21.5%), American red squirrel (28, 13.7%), white-tailed deer (28, 13.7%), and American crows (16, 7.8%). Here, we present the first analysis of the host-feeding preference of different mosquito species in Canada via molecular techniques. Our results on mosquito distribution and behavior will aid in the development of effective mitigation and control strategies to prevent or reduce human/animal health issues in regards to moboviruses.

RevDate: 2020-11-10
CmpDate: 2020-11-10

Jokimäki J, Suhonen J, Benedetti Y, et al (2020)

Land-sharing vs. land-sparing urban development modulate predator-prey interactions in Europe.

Ecological applications : a publication of the Ecological Society of America, 30(3):e02049.

Urban areas are expanding globally as a consequence of human population increases, with overall negative effects on biodiversity. To prevent the further loss of biodiversity, it is urgent to understand the mechanisms behind this loss to develop evidence-based sustainable solutions to preserve biodiversity in urban landscapes. The two extreme urban development types along a continuum, land-sparing (large, continuous green areas and high-density housing) and land-sharing (small, fragmented green areas and low-density housing) have been the recent focus of debates regarding the pattern of urban development. However, in this context, there is no information on the mechanisms behind the observed biodiversity changes. One of the main mechanisms proposed to explain urban biodiversity loss is the alteration of predator-prey interactions. Using ground-nesting birds as a model system and data from nine European cities, we experimentally tested the effects of these two extreme urban development types on artificial ground nest survival and whether nest survival correlates with the local abundance of ground-nesting birds and their nest predators. Nest survival (n = 554) was lower in land-sharing than in land-sparing urban areas. Nest survival decreased with increasing numbers of local predators (cats and corvids) and with nest visibility. Correspondingly, relative abundance of ground-nesting birds was greater in land-sparing than in land-sharing urban areas, though overall bird species richness was unaffected by the pattern of urban development. We provide the first evidence that predator-prey interactions differ between the two extreme urban development types. Changing interactions may explain the higher proportion of ground-nesting birds in land-sparing areas, and suggest a limitation of the land-sharing model. Nest predator control and the provision of more green-covered urban habitats may also improve conservation of sensitive birds in cities. Our findings provide information on how to further expand our cities without severe loss of urban-sensitive species and give support for land-sparing over land-sharing urban development.

RevDate: 2020-11-10
CmpDate: 2020-11-06

Krasheninnikova A, Brucks D, Buffenoir N, et al (2019)

Parrots do not show inequity aversion.

Scientific reports, 9(1):16416 pii:10.1038/s41598-019-52780-8.

Inequity aversion, the negative reaction to unequal treatment, is considered a mechanism for stabilizing cooperative interactions between non-kin group members. However, this might only be adaptive for species that switch cooperative partners. Utilizing a comparative approach, inequity aversion has been assessed in many mammalian species and recently also in corvids and one parrot species, kea, revealing mixed results. To broaden our knowledge about the phylogenetic distribution of inequity aversion, we tested four parrot species in the token exchange paradigm. We varied the quality of rewards delivered to dyads of birds, as well as the effort required to obtain a reward. Blue-headed macaws and African grey parrots showed no reaction to being rewarded unequally. The bigger macaws were less willing to exchange tokens in the "unequal" condition compared to the "equal high" condition in which both birds obtained high quality rewards, but a closer examination of the results and the findings from the control conditions reveal that inequity aversion does not account for it. None of the species responded to inequity in terms of effort. Parrots may not exhibit inequity aversion due to interdependence on their life-long partner and the high costs associated with finding a new partner.

RevDate: 2020-11-06
CmpDate: 2020-11-06

Probst C, Gethmann J, Amler S, et al (2019)

The potential role of scavengers in spreading African swine fever among wild boar.

Scientific reports, 9(1):11450 pii:10.1038/s41598-019-47623-5.

Understanding the transmission patterns of African swine fever (ASF) among wild boar (Sus scrofa) is an issue of major interest, especially in the wake of the current ASF epidemic. Given the high stability of ASF-virus, there is concern about scavengers spreading infectious carcass material in the environment. Here, we describe scavenging activities on 32 wild boar carcasses in their natural habitat in Germany. Using digital cameras, we detected 22 vertebrates at the study sites, thereof two mammal and three bird species scavenging. The most frequently detected species was the raccoon dog Nyctereutes procyonoides (44% of all visits). Raccoon dogs, red foxes (Vulpes vulpes), and buzzards (Buteo buteo) scavenged in the warm and the cold season, while ravens (Corvus corax) and white-tailed eagles (Haliaeetus albicilla) scavenged only in the cold season. In summer, however, insects removed most of the carcass biomass. Although most of the material was consumed on the spot, foxes, raccoon dogs and ravens left the study sites in rare cases with a small piece of meat in their mouths or beaks. We conclude that scavengers represent a minor risk factor for spreading ASF, but may contribute to reducing local virus persistence by metabolizing infected carcasses.

RevDate: 2020-11-03
CmpDate: 2020-11-03

Spanoudis CG, Andreadis SS, Bray DP, et al (2020)

Behavioural response of the house mosquitoes Culex quinquefasciatus and Culex pipiens molestus to avian odours and its reliance on carbon dioxide.

Medical and veterinary entomology, 34(2):129-137.

How Culex (Diptera: Culicidae) mosquitoes select and discriminate between potential avian hosts is critical for understanding the epidemiology of West Nile virus. Therefore, the present authors studied the behavioural responses of Culex quinquefasciatus (Say) and Culex pipiens molestus (Forsskål) to headspace volatiles of three avian species [chicken and pigeon (sexes analysed separately), and magpie], presented either alone or in combination with 600 p.p.m. carbon dioxide (CO2). The attraction of Cx. quinquefasciatus to the headspace volatiles of both sexes of chicken, and of female pigeon, in combination with CO2 was significantly higher than that achieved by the CO2 and solvent control. Although Cx. p. molestus was attracted to headspace volatiles of chickens and magpies, it was repelled by those of female pigeons when combined with CO2 . An increased effect between the avian volatiles and CO2 was observed for Cx. quinquefasciatus, whereas the addition of CO2 had no effect on the attraction of Cx. p. molestus females. The results of this study demonstrate that Cx. quinquefasciatus and Cx. p. molestus are attracted to the odour of potential avian hosts. Future studies aimed at identifying the bioactive volatile compounds in the headspace of chickens may contribute to the potential development of effective surveillance and control tools against Culex species.

RevDate: 2020-10-23
CmpDate: 2020-10-23

Martínez JG, Molina-Morales M, Precioso M, et al (2020)

Age-Related Brood Parasitism and Egg Rejection in Magpie Hosts.

The American naturalist, 195(5):876-885.

When the strength or nature of a host-parasite interaction changes over the host life cycle, the consequences of parasitism can depend on host population age structure. Avian brood parasites reduce hosts' breeding success, and host age may play a role in this interaction if younger hosts are more likely parasitized and/or less able to defend themselves. We analyzed whether the age of female magpie (Pica pica) hosts is associated with parasite attack or their ability to reject foreign eggs. We recorded parasitism and model egg rejection of known-age individuals over their lifetime and established whether the likelihood of parasitism or egg rejection changed with age or longevity. Parasitism probability did not change with female age, and there was a trend toward longer-lived females being less likely to be parasitized. However, model egg rejection probability increased with age for each individual female, and longer-lived females were more prone to reject model eggs. Most females in the population were young, and the majority of them accepted model eggs, suggesting that brood parasites exploiting younger host individuals are benefitting from a lower defense level of their hosts. Our results stress that the intensity of selection by brood parasites may be mediated by the age structure of host populations, a to-date neglected aspect in brood parasite-host research.

RevDate: 2020-10-20

Horn L, Bugnyar T, Griesser M, et al (2020)

Sex-specific effects of cooperative breeding and colonial nesting on prosociality in corvids.

eLife, 9: pii:58139 [Epub ahead of print].

The investigation of prosocial behavior is of particular interest from an evolutionary perspective. Comparisons of prosociality across non-human animal species have, however, so far largely focused on primates, and their interpretation is hampered by the diversity of paradigms and procedures used. Here we present the first systematic comparison of prosocial behavior across multiple species in a taxonomic group outside the primate order, namely the bird family Corvidae. We measured prosociality in 8 corvid species, which vary in the expression of cooperative breeding and colonial nesting. We show that cooperative breeding is positively associated with prosocial behavior across species. Also, colonial nesting is associated with a stronger propensity for prosocial behavior, but only in males. The combined results of our study strongly suggest that both cooperative breeding and colonial nesting, which may both rely on heightened social tolerance at the nest, are likely evolutionary pathways to prosocial behavior in corvids.

RevDate: 2020-10-16
CmpDate: 2020-10-16

England ME, Pearce-Kelly P, Brugman VA, et al (2020)

Culicoides species composition and molecular identification of host blood meals at two zoos in the UK.

Parasites & vectors, 13(1):139.

BACKGROUND: Culicoides biting midges are biological vectors of arboviruses including bluetongue virus (BTV), Schmallenberg virus (SBV) and African horse sickness virus (AHSV). Zoos are home to a wide range of 'at risk' exotic and native species of animals. These animals have a high value both in monetary terms, conservation significance and breeding potential. To understand the risk these viruses pose to zoo animals, it is necessary to characterise the Culicoides fauna at zoos and determine which potential vector species are feeding on which hosts.

METHODS: Light-suction traps were used at two UK zoos: the Zoological Society of London (ZSL) London Zoo (LZ) and ZSL Whipsnade Zoo (WZ). Traps were run one night each week from June 2014 to June 2015. Culicoides were morphologically identified to the species level and any blood-fed Culicoides were processed for blood-meal analysis. DNA from blood meals was extracted and amplified using previously published primers. Sequencing was then carried out to determine the host species.

RESULTS: A total of 11,648 Culicoides were trapped and identified (n = 5880 from ZSL WZ; n = 5768 from ZSL LZ), constituting 25 different species. The six putative vectors of BTV, SBV and AHSV in northern Europe were found at both zoos and made up the majority of the total catch (n = 10,701). A total of 31 host sequences were obtained from blood-fed Culicoides. Culicoides obsoletus/C. scoticus, Culicoides dewulfi, Culicoides parroti and Culicoides punctatus were found to be biting a wide range of mammals including Bactrian camels, Indian rhinoceros, Asian elephants and humans, with Culicoides obsoletus/C. scoticus also biting Darwin's rhea. The bird-biting species, Culicoides achrayi, was found to be feeding on blackbirds, blue tits, magpies and carrion crows.

CONCLUSIONS: To our knowledge, this is the first study to directly confirm blood-feeding of Culicoides on exotic zoo animals in the UK and shows that they are able to utilise a wide range of exotic as well as native host species. Due to the susceptibility of some zoo animals to Culicoides-borne arboviruses, this study demonstrates that in the event of an outbreak of one of these viruses in the UK, preventative and mitigating measures would need to be taken.

RevDate: 2020-10-01

Massen JJM, Haley SM, T Bugnyar (2020)

Azure-winged magpies' decisions to share food are contingent on the presence or absence of food for the recipient.

Scientific reports, 10(1):16147 pii:10.1038/s41598-020-73256-0.

Helping others is a key feature of human behavior. However, recent studies render this feature not uniquely human, and describe discoveries of prosocial behavior in non-human primates, other social mammals, and most recently in some bird species. Nevertheless, the cognitive underpinnings of this prosociality; i.e., whether animals take others' need for help into account, often remain obscured. In this study, we take a first step in investigating prosociality in azure-winged magpies by presenting them with the opportunity to share highly desired food with their conspecifics i) in a situation in which these conspecifics had no such food, ii) in a situation in which they too had access to that highly desired food, and iii) in an open, base-line, situation where all had equal access to the same food and could move around freely. We find that azure-winged magpies regularly share high-value food items, preferably with, but not restricted to, members of the opposite sex. Most notably, we find that these birds, and specifically the females, seem to differentiate between whether others have food or do not have food, and subsequently cater to that lack. Begging calls by those without food seem to function as cues that elicit the food-sharing, but the response to that begging is condition-dependent. Moreover, analyses on a restricted dataset that excluded those events in which there was begging showed exactly the same patterns, raising the possibility that the azure-winged magpies might truly notice when others have access to fewer resources (even in the absence of vocal cues). This sharing behavior could indicate a high level of social awareness and prosociality that should be further investigated. Further studies are needed to establish the order of intentionality at play in this system, and whether azure-winged magpies might be able to attribute desire states to their conspecifics.

RevDate: 2020-09-24

Hunt GR (2020)

New Caledonian crows' basic tool procurement is guided by heuristics, not matching or tracking probe site characteristics.

Animal cognition pii:10.1007/s10071-020-01427-7 [Epub ahead of print].

Contrasting findings made it unclear what cognitive processes New Caledonian crows use to procure suitable tools to solve tool tasks. Most previous studies suggested that their tool procurement is achieved by either trial and error or a simple heuristic. The latter provides a fast and cognitively efficient method for stable, routinized behaviour based on past experience with little or no deliberate decision-making. However, early papers by Chappell and Kacelnik reported that two New Caledonian crows procured tools after closely assessing the tool characteristics required for the task, thus using deliberate decision-making, or a 'customized strategy'. Here, I tested eight New Caledonian crows to determine their default behaviour in basic tool procurement tasks as a check on whether or not they use customized strategies. I used two rigorous experiments closely based on Chappell and Kacelnik's experiments. The crows did not use a customized strategy in either experiment, but their behaviour was clearly consistent with tool procurement predominantly guided by a familiarity heuristic. I discuss potential methodological issues that may have led to different conclusions in Chappell and Kacelnik's studies. Heuristic-guided, routinized behaviour in tool procurement has potential implications for understanding how standardization occurs in the early evolution of complex tool manufacture, both in New Caledonian crows and early humans.

RevDate: 2020-09-23
CmpDate: 2020-09-23

Engel N, Végvári Z, Rice R, et al (2020)

Incubating parents serve as visual cues to predators in Kentish plover (Charadrius alexandrinus).

PloS one, 15(7):e0236489.

Ground-nesting birds face many challenges to reproduce successfully, with nest predation being the main cause of reproductive failure. Visual predators such as corvids and egg-eating raptors, are among the most common causes of nest failure; thus, parental strategies that reduce the risk of visual nest predation should be favored by selection. To date, most research has focused on egg crypsis without considering adult crypsis, although in natural circumstances the eggs are covered by an incubating parent most of the time. Here we use a ground-nesting shorebird, the Kentish plover (Charadrius alexandrinus) as model species to experimentally test whether decoy parents influence nest predation. Using artificial nests with a male decoy, a female decoy or no decoy, we found that the presence of a decoy increased nest predation (N = 107 nests, p < 0.001). However, no difference was found in predation rates between nests with a male versus female decoy (p > 0.05). Additionally, we found that nests in densely vegetated habitats experienced higher survival compared to nests placed in sparsely vegetated habitats. Nest camera images, predator tracks and marks left on eggs identified the brown-necked raven (Corvus ruficollis) as the main visual nest predator. Our study suggests that the presence of incubating parents may enhance nest detectability to visual predators. However, parents may reduce the predation risk by placing a nest in sites where they are covered by vegetation. Our findings highlight the importance of nest site selection not only regarding egg crypsis but also considering incubating adult camouflage.

RevDate: 2020-09-16
CmpDate: 2020-09-16

Bravo C, Pays O, Sarasa M, et al (2020)

Revisiting an old question: Which predators eat eggs of ground-nesting birds in farmland landscapes?.

The Science of the total environment, 744:140895.

Nest predation is a major cause of reproductive failure in birds, but predator identity often remains unknown. Additionally, although corvids are considered major nest predators in farmland landscapes, whether breeders or floaters are involved remains contentious. In this study, we aimed to identify nest predators using artificial nests, and test whether territorial or non-breeders carrion crow (Corvus corone) and Eurasian magpie (Pica pica) were most likely involved. We set up an experiment with artificial ground nests (n = 1429) in farmland landscapes of western France, and assessed how different combinations of egg size and egg material (small plasticine egg, large plasticine egg, quail and natural hen eggs) might influence predation rates and predator species involved. Nest predators were identified using remotely triggered cameras and marks left in plasticine eggs. Corvids were by far the predators most involved (almost 80% of all predation events), independent of egg type. Carrion crows alone were involved in 60% of cases. Probability of predation increased with egg size, and predation rate was higher for natural than for artificial eggs, suggesting that, in addition to egg size, predators might perceive plasticine and natural eggs differently. Predation rates of artificial nests by corvids were related significantly to corvid abundance, and far more to breeder than floater abundances, for both carrion crows and magpies. This study emphasizes the importance of identifying predators at species level, and considering their social status when assessing corvid abundance impact on prey population dynamics. Combining camera traps and plasticine eggs can achieve this objective. Given the high predation rate by carrion crows, a better understanding of landscape-mediated changes in predator diet seems mandatory to design mitigation schemes able to confront ecological challenges raised by generalist predators.

RevDate: 2020-09-14
CmpDate: 2020-09-14

Moberly AC, J Reed (2019)

Making Sense of Sentences: Top-Down Processing of Speech by Adult Cochlear Implant Users.

Journal of speech, language, and hearing research : JSLHR, 62(8):2895-2905.

Purpose Speech recognition relies upon a listener's successful pairing of the acoustic-phonetic details from the bottom-up input with top-down linguistic processing of the incoming speech stream. When the speech is spectrally degraded, such as through a cochlear implant (CI), this role of top-down processing is poorly understood. This study explored the interactions of top-down processing, specifically the use of semantic context during sentence recognition, and the relative contributions of different neurocognitive functions during speech recognition in adult CI users. Method Data from 41 experienced adult CI users were collected and used in analyses. Participants were tested for recognition and immediate repetition of speech materials in the clear. They were asked to repeat 2 sets of sentence materials, 1 that was semantically meaningful and 1 that was syntactically appropriate but semantically anomalous. Participants also were tested on 4 visual measures of neurocognitive functioning to assess working memory capacity (Digit Span; Wechsler, 2004), speed of lexical access (Test of Word Reading Efficiency; Torgeson, Wagner, & Rashotte, 1999), inhibitory control (Stroop; Stroop, 1935), and nonverbal fluid reasoning (Raven's Progressive Matrices; Raven, 2000). Results Individual listeners' inhibitory control predicted recognition of meaningful sentences when controlling for performance on anomalous sentences, our proxy for the quality of the bottom-up input. Additionally, speed of lexical access and nonverbal reasoning predicted recognition of anomalous sentences. Conclusions Findings from this study identified inhibitory control as a potential mechanism at work when listeners make use of semantic context during sentence recognition. Moreover, speed of lexical access and nonverbal reasoning were associated with recognition of sentences that lacked semantic context. These results motivate the development of improved comprehensive rehabilitative approaches for adult patients with CIs to optimize use of top-down processing and underlying core neurocognitive functions.

RevDate: 2020-09-02
CmpDate: 2020-09-02

Hirschl RB, Newman E, Cooke-Barber J, et al (2020)

APSA 5.0: Saving even more lifetimes the Jay and Margie Grosfeld presidential symposium.

Journal of pediatric surgery, 55(1):2-17.

In light of APSA's 50th Anniversary, the typical Presidential Address was transformed into a "symposium" consisting of talks on the maturation of our organization to APSA 5.0 and the issues and opportunities related to its internal and external environment, especially as they apply to our pediatric surgical patients. Speakers included the President and experts in the fields of diversity, as well as inequity and poverty in the United States.

RevDate: 2020-07-30
CmpDate: 2020-07-30

Congdon JV, Hahn AH, Filippi P, et al (2019)

Hear them roar: A comparison of black-capped chickadee (Poecile atricapillus) and human (Homo sapiens) perception of arousal in vocalizations across all classes of terrestrial vertebrates.

Journal of comparative psychology (Washington, D.C. : 1983), 133(4):520-541.

Recently, evidence for acoustic universals in vocal communication was found by demonstrating that humans can identify levels of arousal in vocalizations produced by species across three biological classes (Filippi et al., 2017). Here, we extend this work by testing whether two vocal learning species, humans and chickadees, can discriminate vocalizations of high and low arousal using operant discrimination go/no-go tasks. Stimuli included vocalizations from nine species: giant panda, American alligator, common raven, hourglass treefrog, African elephant, Barbary macaque, domestic pig, black-capped chickadee, and human. Subjects were trained to respond to high or low arousal vocalizations, then tested with additional high and low arousal vocalizations produced by each species. Chickadees (Experiment 1) and humans (Experiment 2) learned to discriminate between high and low arousal stimuli and significantly transferred the discrimination to additional panda, human, and chickadee vocalizations. Finally, we conducted discriminant function analyses using four acoustic measures, finding evidence suggesting that fundamental frequency played a role in responding during the task. However, these analyses also suggest roles for other acoustic factors as well as familiarity. In sum, the results from these studies provide evidence that chickadees and humans are capable of perceiving arousal in vocalizations produced by multiple species. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

RevDate: 2020-07-30
CmpDate: 2020-07-30

Cumbo E, Cumbo S, Torregrossa S, et al (2019)

Treatment Effects of Vortioxetine on Cognitive Functions in Mild Alzheimer's Disease Patients with Depressive Symptoms: A 12 Month, Open-Label, Observational Study.

The journal of prevention of Alzheimer's disease, 6(3):192-197.

BACKGROUND/OBJECTIVES: depressive symptoms are common in Alzheimer's disease(AD). Aim of the study was to investigate the efficacy of vortioxetine compared with other conventional antidepressants on cognitive functions in AD patients with depressive symptoms.

DESIGN: Prospective, randomized, 12 month, parallel-group study.

SETTING: All participants were evaluated on-site at Neurodegenerative Disorders Unit, ASP2 Caltanissetta(Italy).

PARTICIPANTS: 108(71 female, 37 male) AD patients with depression(mean age 76.7 ± 4.3).

INTERVENTION: Randomized subjects received vortioxetine, 15 mg/day(n=36) or other common antidepressants(n=72).

MEASURES: Primary outcome was change from baseline in the MMSE; secondary outcomes were change in Attentive Matrices, Raven Coloured Progressive Matrices, Digit Span, HAM-D and Cornell scale.

RESULTS: Statistically significant improvement vs. controls was observed for vortioxetine on most of the cognitive tests and showed significantly baseline-to-endpoint reduction in both HAM-D and Cornell total scores.The most commonly reported adverse events were nausea and headache for votioxetine; nausea in the control group.

CONCLUSIONS: Vortioxetine had a beneficial effect on cognition and mood in elderly AD patients and was safe and well tolerated.

RevDate: 2020-07-18

Lee CY, Peralta-Sánchez JM, Martínez-Bueno M, et al (2020)

The gut microbiota of brood parasite and host nestlings reared within the same environment: disentangling genetic and environmental effects.

The ISME journal pii:10.1038/s41396-020-0719-y [Epub ahead of print].

Gut microbiota are essential for host health and survival, but we are still far from understanding the processes involved in shaping their composition and evolution. Controlled experimental work under lab conditions as well as human studies pointed at environmental factors (i.e., diet) as the main determinant of the microbiota with little evidence of genetic effects, while comparative interspecific studies detected significant phylogenetic effects. Different species, however, also differ in diet, feeding behavior, and environmental characteristics of habitats, all of which also vary interspecifically, and, therefore, can potentially explain most of the detected phylogenetic patterns. Here, we take advantage of the reproductive strategy of avian brood parasites and investigate gut microbiotas (esophageal (food and saliva) and intestinal) of great spotted cuckoo (Clamator glandarius) and magpie (Pica pica) nestlings that grow in the same nests. We also estimated diet received by each nestling and explored its association with gut microbiota characteristics. Although esophageal microbiota of magpies and great spotted cuckoos raised within the same environment (nest) did not vary, the microbiota of cloacal samples showed clear interspecific differences. Moreover, diet of great spotted cuckoo and magpie nestlings explained the microbiota composition of esophageal samples, but not of cloaca samples. These results strongly suggest a genetic component determining the intestinal microbiota of host and parasitic bird species, indicating that interspecific differences in gut morphology and physiology are responsible for such interspecific differences.

RevDate: 2020-07-18

Wei W, Zhen Q, Tang Z, et al (2020)

Risk assessment in the plateau pika (Ochotona curzoniae): intensity of behavioral response differs with predator species.

BMC ecology, 20(1):41 pii:10.1186/s12898-020-00309-3.

BACKGROUND: The ability of a prey species to assess the risk that a predator poses can have important fitness advantages for the prey species. To better understand predator-prey interactions, more species need to be observed to determine how prey behavioral responses differ in intensity when approached by different types of predators. The plateau pika (Ochotona curzoniae) is preyed upon by all predators occurring in its distribution area. Therefore, it is an ideal species to study anti-predator behavior. In this study, we investigated the intensity of anti-predator behavior of pikas in response to visual cues by using four predator species models in Maqu County on the eastern Qinghai-Tibetan Plateau.

RESULTS: The behavioral response metrics, such as Flight Initiation Distance (FID), the hiding time and the percentage of vigilance were significantly different when exposed to a Tibetan fox, a wolf, a Saker falcon and a large-billed crow, respectively. Pikas showed a stronger response to Saker falcons compared to any of the other predators.

CONCLUSIONS: Our results showed that pikas alter their behavioral (such as FID, the hiding time and the vigilance) response intensity to optimally balance the benefits when exposed to different taxidermy predator species models. We conclude that pikas are able to assess their actual risk of predation and show a threat-sensitive behavioral response.

RevDate: 2020-07-14

Baciadonna L, Cornero FM, Emery NJ, et al (2020)

Convergent evolution of complex cognition: Insights from the field of avian cognition into the study of self-awareness.

Learning & behavior pii:10.3758/s13420-020-00434-5 [Epub ahead of print].

Pioneering research on avian behaviour and cognitive neuroscience have highlighted that avian species, mainly corvids and parrots, have a cognitive tool kit comparable with apes and other large-brained mammals, despite conspicuous differences in their neuroarchitecture. This cognitive tool kit is driven by convergent evolution, and consists of complex processes such as casual reasoning, behavioural flexibility, imagination, and prospection. Here, we review experimental studies in corvids and parrots that tested complex cognitive processes within this tool kit. We then provide experimental examples for the potential involvement of metacognitive skills in the expression of the cognitive tool kit. We further expand the discussion of cognitive and metacognitive abilities in avian species, suggesting that an integrated assessment of these processes, together with revised and multiple tasks of mirror self-recognition, might shed light on one of the most highly debated topics in the literature-self-awareness in animals. Comparing the use of multiple assessments of self-awareness within species and across taxa will provide a more informative, richer picture of the level of consciousness in different organisms.

RevDate: 2020-07-02

Boucherie PH, Blum C, T Bugnyar (2020)

Effect of rearing style on the development of social behaviour in young ravens (Corvus corax).

Ethology : formerly Zeitschrift fur Tierpsychologie, 126(6):595-609.

Early social experiences can affect the development and expression of individual social behaviour throughout life. In particular, early-life social deprivations, notably of parental care, can later have deleterious consequences. We can, therefore, expect rearing procedures such as hand-raising-widely used in ethology and socio-cognitive science-to alter the development of individual social behaviour. We investigated how the rearing style later affected (a) variation in relationship strength among peers and (b) individuals' patterns of social interactions, in three captive groups of juvenile non-breeders consisting of either parent-raised or hand-raised birds, or a mix of both rearing styles. In the three groups, irrespectively of rearing style: strongest relationships (i.e., higher rates of association and affiliations) primarily emerged among siblings and familiar partners (i.e., non-relatives encountered in early life), and mixed-sex and male-male partners established relationships of similar strength, indicating that the rearing style does not severely affect the quality and structure of relationships in young ravens. However, compared to parent-raised ravens, hand-raised ravens showed higher connectedness, i.e., number of partners with whom they mainly associated and affiliated, but formed on average relationships of lower strength, indicating that social experience in early life is not without consequences on the development of ravens' patterns of social interaction. The deprivation of parental care associated with the presence of same-age peers during hand-raising seemed to maximize ravens' propensity to interact with others, indicating that besides parents, interactions with same-age peers matter. Opportunities to interact with, and socially learn from peers, might thus be the key to the acquisition of early social competences in ravens.

RevDate: 2020-07-02
CmpDate: 2020-07-02

McMillan JR, Marcet PL, Hoover CM, et al (2019)

Feeding Success and Host Selection by Culex quinquefasciatus Say Mosquitoes in Experimental Trials.

Vector borne and zoonotic diseases (Larchmont, N.Y.), 19(7):540-548.

Arthropod vector feeding preferences are defined as an overutilization of a particular host species given its abundance in relationship to other species in the community. Numerous methods exist to quantify vector feeding preferences; however, controlled host choice experiments are generally an underutilized approach. In this report, we present results from controlled vector host choice experiments using Culex quinquefasciatus Say (Diptera: Culicidae) mosquitoes and wild avian hosts identified as important contributors to West Nile virus (WNv) transmission in Atlanta, Georgia, United States. In each experiment, we allowed lab-reared F1Cx. quinquefasciatus to feed freely overnight on two avian individuals of a different species (i.e., northern cardinals, American robins, blue jays, brown thrashers, and gray catbirds). We then estimated WNv transmission potential using vectorial capacity and R0. We found that mosquito blood feeding success was extremely variable among experimental replicates and that patterns of host choice only occasionally aggregated to a particular bird species. Vectorial capacity was highest for American robins and blue jays due to these species' higher reservoir competence for WNv and greater probabilities of mosquito selection of these species. Despite species-specific differences in vectorial capacity, total community capacity was similar among species pairs. R0 estimates were qualitatively similar to capacity, and R0 was below and above unity across species pairs. Our results provide empirical evidence that C. quinquefasciatus is an opportunistic blood feeder and highlight how variability in vector-host contact rates as well as host community composition can influence the likelihood of WNv transmission in avian communities.

RevDate: 2020-07-01
CmpDate: 2020-07-01

Lambert ML, M Osvath (2020)

Investigating information seeking in ravens (Corvus corax).

Animal cognition, 23(4):671-680.

Measuring the responses of non-human animals to situations of uncertainty is thought to shed light on an animal's metacognitive processes; namely, whether they monitor their own knowledge states. For example, when presented with a foraging task, great apes and macaques selectively seek information about the location of a food item when they have not seen where it was hidden, compared to when they have. We presented this same information seeking task to ravens, in which a food item was hidden in one of three containers, and subjects could either watch where the food was hidden, infer its location through visual or auditory clues, or were given no information. We found that unlike several ape species and macaques, but similar to capuchin monkeys, the ravens looked inside at least one tube on every trial, but typically only once, inside the baited tube, when they had either witnessed it being baited or could visually infer the reward's location. In contrast, subjects looked more often within trials in which they had not witnessed the baiting or were provided with auditory cues about the reward's location. Several potential explanations for these ceiling levels of looking are discussed, including how it may relate to the uncertainty faced by ravens when retrieving food caches.

RevDate: 2020-07-01
CmpDate: 2020-07-01

Miller R, Frohnwieser A, Schiestl M, et al (2020)

Delayed gratification in New Caledonian crows and young children: influence of reward type and visibility.

Animal cognition, 23(1):71-85.

Self-control underlies cognitive abilities such as decision making and future planning. Delay of gratification is a measure of self-control and involves obtaining a more valuable outcome in the future by tolerating a delay or investing a greater effort in the present. Contextual issues, such as reward visibility and type, may influence delayed gratification performance, although there has been limited comparative investigation between humans and other animals, particularly non-primate species. Here, we adapted an automated 'rotating tray' paradigm used previously with capuchin monkeys to test for delay of gratification ability that requires little pre-test training, where the subject must forgo an immediate, less preferred reward for a delayed, more preferred one. We tested New Caledonian crows and 3-5-year-old human children. We manipulated reward types to differ in quality or quantity (Experiments 1 and 2) as well as visibility (Experiment 2). In Experiments 1 and 2, both species performed better when the rewards varied in quality as opposed to quantity, though performed above chance in both conditions. In Experiment 1, both crows and children were able to delay gratification when both rewards were visible. In Experiment 2, 5-year-old children outperformed 3- and 4-year olds, though overall children still performed well, while the crows struggled when reward visibility was manipulated, a result which may relate to difficulties in tracking the experimenters' hands during baiting. We discuss these findings in relation to the role of contextual issues on self-control when making species comparisons and investigating the mechanisms of self-control.

RevDate: 2020-06-16

Chakarov N, Kampen H, Wiegmann A, et al (2020)

Blood parasites in vectors reveal a united blackfly community in the upper canopy.

Parasites & vectors, 13(1):309 pii:10.1186/s13071-020-04177-0.

BACKGROUND: The behaviour of blood-sucking arthropods is a crucial determinant of blood protozoan distribution and hence of host-parasite coevolution, but it is very challenging to study in the wild. The molecular identification of parasite lineages in vectors can be a useful key to understand the behaviour and transmission patterns realised by these vectors.

METHODS: In this study, we collected blackflies around nests of three raptor species in the upper forest canopy in central Europe and examined the presence of vertebrate DNA and haemosporidian parasites in them. We molecularly analysed 156 blackfly individuals, their vertebrate blood meals, and the haemosporidian parasite lineages they carried.

RESULTS: We identified nine species of Simulium blackflies, largely belonging to the subgenera Nevermannia and Eusimulium. Only 1% of the collected specimens was visibly engorged, and only 4% contained remains of host DNA. However, in 29% of the blackflies Leucocytozoon lineages were identified, which is evidence of a previous blood meal on an avian host. Based on the known vertebrate hosts of the recorded Leucocytozoon lineages, we can infer that large and/or abundant birds, such as thrushes, crows, pigeons, birds of prey, owls and tits are the main targets of ornithophilic blackflies in the canopy. Blackfly species contained similar proportions of host group-specific parasite lineages and thus do not appear to be associated with particular host groups.

CONCLUSIONS: The Leucocytozoon clade infecting thrushes, crows, and pigeons present in most represented blackfly species suggests a lack of association between hosts and blackflies, which can increase the probability of host switches of blood parasites. However, the composition of the simuliid species differed between nests of common buzzards, goshawks and red kites. This segregation can be explained by coinciding habitat preferences between host and vector, and may lead to the fast speciation of Leucocytozoon parasites. Thus, subtle ecological preferences and lack of host preference of vectors in the canopy may enable both parasite diversification and host switches, and enforce a habitat-dependent evolution of avian malaria parasites and related haemosporidia.

RevDate: 2020-06-02

Wang L, Luo Y, Wang H, et al (2020)

Azure-winged magpies fail to understand the principle of mirror imaging.

Behavioural processes pii:S0376-6357(19)30396-1 [Epub ahead of print].

Mirror self-recognition (MSR) is considered a crucial step in the emergence of self-cognition. The MSR paradigm has become a standard method for evaluating self-cognition in several species. For example, Eurasian magpies and Indian house crows have passed the mark test for self-cognition, whereas efforts to find MSR in other corvid species have failed. However, no literature has conducted MSR tests on azure-winged magpies, a species of corvids. Therefore, the current research aimed to investigate the MSR behaviours of azure-winged magpies upon looking into a mirror for the first time. The study included four tests: (1) mirror preference and standardised mirror exploration, (2) single vertical mirror test, (3) mark test and (4) mirror-triggered search test. The azure-winged magpies displayed immense curiosity towards the mirror and their images in the mirror in Test 1&2. In the subsequent mark tests, they failed to recognise themselves in the mirror and regarded their images as conspecifics. Behaviour analysis showed no significant difference between marked and unmarked behaviours. Finally they seemed to infer the presence of bait from the image in the mirror, but were found to fail to understand that the location of the bait in the mirror was the same as that in the real world. For a better insight into the MSR behaviour of azure-winged magpies, research studies involving prolonged mirror exposure and training are recommended.

RevDate: 2020-05-28

Brecht KF, Müller J, A Nieder (2020)

Carrion crows (Corvus corone corone) fail the mirror mark test yet again.

Journal of comparative psychology (Washington, D.C. : 1983) pii:2020-37266-001 [Epub ahead of print].

The mirror mark test is generally considered to be an indicator of an animal's ability to recognize itself in the mirror. For this test, an animal is confronted with a mirror and has a mark placed where it can see the mark only with the help of the mirror. When the animal extensively touches or interacts with the mark, compared with control conditions, the mirror mark test is passed. Many nonhuman animal species have been tested, but few have succeeded. After magpies and Indian house crows passed, there has been a sustained interest to find out whether other corvids would pass the mirror mark test. Here, we presented 12 carrion crows (Corvus corone corone) with the mirror mark test. There was no significant increase of mark-directed behavior in the mirror mark test, compared with control conditions. We find very few occasions of mark-directed behaviors and have to interpret them in the context of self-directed behavior more generally. In addition, we show that our crows were motivated to interact with a mark when it was visible to them without the aid of a mirror. We conclude that our crows fail the test, and thereby replicate previous studies showing a similar failure in corvids, and crows in particular. Because our study adds to the growing literature of corvids failing the mirror mark test, the issue of mirror self-recognition in these birds remains controversial. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

RevDate: 2020-05-21

Clarke MJ, Fraser EE, IG Warkentin (2020)

Fine spatial-scale variation in scavenger activity influences avian mortality assessments on a boreal island.

PloS one, 15(5):e0233427 pii:PONE-D-19-28121.

Bird-window collisions are the second leading cause of human-related avian mortality for songbirds in Canada. Our ability to accurately estimate the number of fatalities caused by window collisions is affected by several biases, including the removal of carcasses by scavengers prior to those carcasses being detected during surveys. We investigated the role of scavenger behavior in modifying perceived carcass removal rate while describing habitat-specific differences for the scavengers present in a relatively scavenger-depauperate island ecosystem. We used motion activated cameras to monitor the fate of hatchling chicken carcasses placed at building (under both windows and windowless walls) and forest (open and closed canopy) sites in western Newfoundland, Canada. We recorded the identity of scavengers, timing of events, and frequency of repeat scavenging at sites. Using 2 treatments, we also assessed how scavenging varied with 2 levels of carcass availability (daily versus every third day). Scavenger activities differed substantially between forest and building sites. Only common ravens (Corvus corax) removed carcasses at building sites, with 25 of 26 removals occurring under windows. Burying beetles (Nicrophorus spp.) dominated scavenging at forest sites (14 of 18 removals), completely removing carcasses from sight in under 24 hours. Availability had no effect on removal rate. These findings suggest that ravens look for carcasses near building windows, where bird-window collision fatalities create predictable food sources, but that this learning preceded the study. Such behavior resulted in highly heterogeneous scavenging rates at fine spatial scales indicating the need for careful consideration of carcass and camera placement when monitoring scavenger activity. Our observations of burying beetle activity indicate that future studies investigating bird collision mortality near forested habitats and with infrequent surveys, should consider local invertebrate community composition during survey design. The high incidence of invertebrate scavenging may compensate for the reduced vertebrate scavenger community of insular Newfoundland.

RevDate: 2020-05-18
CmpDate: 2020-05-12

Miller R, Gruber R, Frohnwieser A, et al (2020)

Decision-making flexibility in New Caledonian crows, young children and adult humans in a multi-dimensional tool-use task.

PloS one, 15(3):e0219874.

The ability to make profitable decisions in natural foraging contexts may be influenced by an additional requirement of tool-use, due to increased levels of relational complexity and additional work-effort imposed by tool-use, compared with simply choosing between an immediate and delayed food item. We examined the flexibility for making the most profitable decisions in a multi-dimensional tool-use task, involving different apparatuses, tools and rewards of varying quality, in 3-5-year-old children, adult humans and tool-making New Caledonian crows (Corvus moneduloides). We also compared our results to previous studies on habitually tool-making orangutans (Pongo abelii) and non-tool-making Goffin's cockatoos (Cacatua goffiniana). Adult humans, cockatoos and crows, but not children and orangutans, did not select a tool when it was not necessary, which was the more profitable choice in this situation. Adult humans, orangutans and cockatoos, but not crows and children, were able to refrain from selecting non-functional tools. By contrast, the birds, but not the primates tested, struggled to attend to multiple variables-where two apparatuses, two tools and two reward qualities were presented simultaneously-without extended experience. These findings indicate: (1) in a similar manner to humans and orangutans, New Caledonian crows and Goffin's cockatoos can flexibly make profitable decisions in some decision-making tool-use tasks, though the birds may struggle when tasks become more complex; (2) children and orangutans may have a bias to use tools in situations where adults and other tool-making species do not.

RevDate: 2020-05-14

Soler M, Colmenero JM, Pérez-Contreras T, et al (2020)

Replication of the mirror mark test experiment in the magpie (Pica pica) does not provide evidence of self-recognition.

Journal of comparative psychology (Washington, D.C. : 1983) pii:2020-31404-001 [Epub ahead of print].

Self-recognition in animals is demonstrated when individuals pass the mark test. Formerly, it was thought that self-recognition was restricted to humans, great apes, and certain mammals with large brains and highly evolved social cognition. However, 1 study showed that 2 out of 5 magpies (Pica pica) passed the mark test, suggesting that magpies have a similar level of cognitive abilities to great apes. The scientific advancement depends on confidence in published science, and this confidence can be reached only after rigorous replication of published studies. Here, we present a close replication of the magpie study but using a larger sample size while following a very similar experimental protocol. Like the previous study, in our experiment, magpies showed both social and self-directed behavior more frequently in front of the mirror versus a control cardboard stimulus. However, during the mark test, self-directed behavior proved more frequent in front of the cardboard than in the mirror. Thus, our replication failed to confirm the previous results. Close replications, while not disproving an earlier study, identify results that should be considered with caution. Therefore, more replication studies and additional experimental work is needed to unambiguously demonstrate that magpies are consistently able to pass the mark test. The existence of compelling evidence of self-recognition in other corvid species is discussed in depth. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

RevDate: 2020-05-06

Gill LF, van Schaik J, von Bayern AMP, et al (2020)

Genetic monogamy despite frequent extrapair copulations in "strictly monogamous" wild jackdaws.

Behavioral ecology : official journal of the International Society for Behavioral Ecology, 31(1):247-260.

"Monogamy" refers to different components of pair exclusiveness: the social pair, sexual partners, and the genetic outcome of sexual encounters. Avian monogamy is usually defined socially or genetically, whereas quantifications of sexual behavior remain scarce. Jackdaws (Corvus monedula) are considered a rare example of strict monogamy in songbirds, with lifelong pair bonds and little genetic evidence for extrapair (EP) offspring. Yet jackdaw copulations, although accompanied by loud copulation calls, are rarely observed because they occur visually concealed inside nest cavities. Using full-day nest-box video surveillance and on-bird acoustic bio-logging, we directly observed jackdaw sexual behavior and compared it to the corresponding genetic outcome obtained via molecular parentage analysis. In the video-observed nests, we found genetic monogamy but frequently detected forced EP sexual behavior, accompanied by characteristic male copulation calls. We, thus, challenge the long-held notion of strict jackdaw monogamy at the sexual level. Our data suggest that male mate guarding and frequent intrapair copulations during the female fertile phase, as well as the forced nature of the copulations, could explain the absence of EP offspring. Because EP copulation behavior appeared to be costly for both sexes, we suggest that immediate fitness benefits are an unlikely explanation for its prevalence. Instead, sexual conflict and dominance effects could interact to shape the spatiotemporal pattern of EP sexual behavior in this species. Our results call for larger-scale investigations of jackdaw sexual behavior and parentage and highlight the importance of combining social, sexual, and genetic data sets for a more complete understanding of mating systems.

RevDate: 2020-05-05
CmpDate: 2020-05-05

Huerta-Franco MR, Vargas-Luna M, Somoza X, et al (2019)

Gastric responses to acute psychological stress in climacteric women: a pilot study.

Menopause (New York, N.Y.), 26(5):469-475.

OBJECTIVE: Women exhibit reduced ovarian sex hormones during the menopausal period that result in well-known physical and psychological symptoms. However, symptoms related to gastric motility (GM) have not been thoroughly investigated. We hypothesized that stress response gastric motility (SRGM) is lower in postmenopausal (PM) and perimenopausal (PERIM) women than in premenopausal (PREM) women. Estrogenic decline leads to neuroendocrine changes in different areas of the brain. These changes can result in hypothalamic vasomotor symptoms, disorders in eating behaviours, and altered blood pressure, in addition to psychological disorders such as stress, anxiety, depression, and irritability related to alterations in the limbic system.

METHODS: In this pilot study, 55 PREM, PERIM, and PM women were clinically evaluated using the Nowack stress profile (SP) and State-Trait Anxiety Inventory (STAI). GM was assessed via electrical bioimpedance using two psychological stress tests (Stroop and Raven tests).

RESULTS: Basal SP and STAI-anxiety test scores were similar among the three groups of women (P > 0.05). PERIM women had lower GM in the basal state (P < 0.05) than did other women. PREM and PM women had significantly decreased GM during the stress tests (P < 0.05). However, PERIM did not exhibit GM changes during stress tests (P > 0.05).

CONCLUSION: Changes in sex hormones during PERIM may affect GM and SRGM.

RevDate: 2020-04-24
CmpDate: 2020-04-24

Matsui H, EI Izawa (2019)

Rapid adjustment of pecking trajectory to prism-induced visual shifts in crows as compared with pigeons.

The Journal of experimental biology, 222(Pt 4): pii:jeb.182345.

Pecking in birds is analogous to reaching and grasping movements in primates. Earlier studies on visuomotor control in birds, which were conducted mostly in pigeons, suggested that avian pecking is controlled feedforwardly, and is out of the control of visual guidance during movement. However, recent studies using crows suggested a role of vision in pecking control during movement. To unveil what visuomotor mechanisms underlie the flexibility of pecking in crows, we examined whether pigeons and crows adjust their pecking to the visual distortion induced by prisms. Because prisms induce visual shifts of object positions, birds were required to adjust their movements. Pecking kinematics were examined before and after attaching prisms in front of the birds' eyes. Analysis of lateral deviation caused by the prisms showed that crows rapidly adjusted their pecking trajectories, but pigeons did so slowly. Angular displacement also increased in pigeons after attachment of the prism, but decreased in crows. These responses to prisms were consistent among individuals in pigeons but varied in crows, though the adjustment of pecking commonly succeeded in crows. These results suggest that pecking in pigeons predominantly involves feedforward control and that the movement is determined depending on the visual information available before the initiation of pecking. In contrast, the results from crows suggest that their pecking trajectories are corrected during the movement, supporting on-line visual control. Our findings provide the first evidence to suggest the on-line visual control of pecking in birds.

RevDate: 2020-03-23

Gallego-Abenza M, Loretto MC, T Bugnyar (2020)

Decision time modulates social foraging success in wild common ravens, Corvus corax.

Ethology : formerly Zeitschrift fur Tierpsychologie, 126(4):413-422.

Social foraging provides several benefits for individuals but also bears the potential costs of higher competition. In some species, such competition arises through kleptoparasitism, that is when an animal takes food which was caught or collected by a member of its social group. Except in the context of caching, few studies have investigated how individuals avoid kleptoparasitism, which could be based on physical strength/dominance but also cognitive skills. Here, we investigated the foraging success of wild common ravens, Corvus corax, experiencing high levels of kleptoparasitism from conspecifics when snatching food from the daily feedings of captive wild boars in a game park in the Austrian Alps. Success in keeping the food depended mainly on the individuals' age class and was positively correlated with the time to make a decision in whether to fly off with food or consume it on site. While the effect of age class suggests that dominant and/or experienced individuals are better in avoiding kleptoparasitism, the effect of decision time indicates that individuals benefit from applying cognition to such decision-making, independently of age class. We discuss our findings in the context of the ecological and social intelligence hypotheses referring to the development of cognitive abilities. We conclude that investigating which factors underline kleptoparasitism avoidance is a promising scenario to test specific predictions derived from these hypotheses.

RevDate: 2020-03-17
CmpDate: 2020-03-17

Schlötelburg A, Plekat A, Bellingrath-Kimura S, et al (2020)

Self-service traps inspected by avian and terrestrial predators as a management option for rodents.

Pest management science, 76(1):103-110.

BACKGROUND: Worldwide, serval rodent species are major pests in agricultural landscapes. A vole-specific tub-trap combining trapping and natural predators was developed to minimize the migration of rodents into agricultural crops. The trap was tested in enclosures in terms of its trapability of common voles (Microtus arvalis Pallas) and in the field regarding predator access and removal of voles, both in comparison to a commercially available self-service trap (standby-box).

RESULTS: The trapability of voles was equal for tub-traps and standby-boxes. The removal of voles occurred four times more often from tub-traps by a wider variety of predators (e.g. smaller terrestrial predators, birds of prey). Visits by predators were most likely if study sites were not surrounded by artificial surfaces (70% visit probability by terrestrial predators) or if they were in areas that were more than 25% (semi)natural (95% visit probability by avian predators). Furthermore, visits by avian predators increased with time and a learning effect could be demonstrated for magpies (Pica pica L.). From the first to the fifth day, the visit probability of magpies quadrupled.

CONCLUSIONS: Visits by predators decreased with increasing cover of artificial surfaces or decreasing cover of (semi)natural areas, proving the importance of (semi)natural areas in the agricultural landscape. Long-term trials with different baiting techniques and in landscapes characterized by organic farming should be conducted to ensure the regular removal of voles. The use of tub-traps that are frequently visited by predators could support crop protection, which might limit the use of rodenticide and the associated exposure risk of non-target wildlife. © 2019 Society of Chemical Industry.

RevDate: 2020-03-03
CmpDate: 2020-03-03

Gruber R, Schiestl M, Boeckle M, et al (2019)

New Caledonian Crows Use Mental Representations to Solve Metatool Problems.

Current biology : CB, 29(4):686-692.e3.

One of the mysteries of animal problem-solving is the extent to which animals mentally represent problems in their minds. Humans can imagine both the solution to a problem and the stages along the way [1-3], such as when we plan one or two moves ahead in chess. The extent to which other animals can do the same is far less clear [4-25]. Here, we presented New Caledonian crows with a series of metatool problems where each stage was out of sight of the others and the crows had to avoid either a distractor apparatus containing a non-functional tool or a non-functional apparatus containing a functional tool. Crows were able to mentally represent the sub-goals and goals of metatool problems: crows kept in mind the location and identities of out-of-sight tools and apparatuses while planning and performing a sequence of tool behaviors. This provides the first conclusive evidence that birds can plan several moves ahead while using tools.

RevDate: 2020-02-27
CmpDate: 2020-02-27

Brecht KF, Hage SR, Gavrilov N, et al (2019)

Volitional control of vocalizations in corvid songbirds.

PLoS biology, 17(8):e3000375 pii:PBIOLOGY-D-19-00036.

Songbirds are renowned for their acoustically elaborate songs. However, it is unclear whether songbirds can cognitively control their vocal output. Here, we show that crows, songbirds of the corvid family, can be trained to exert control over their vocalizations. In a detection task, three male carrion crows rapidly learned to emit vocalizations in response to a visual cue with no inherent meaning (go trials) and to withhold vocalizations in response to another cue (catch trials). Two of these crows were then trained on a go/nogo task, with the cue colors reversed, in addition to being rewarded for withholding vocalizations to yet another cue (nogo trials). Vocalizations in response to the detection of the go cue were temporally precise and highly reliable in all three crows. Crows also quickly learned to withhold vocal output in nogo trials, showing that vocalizations were not produced by an anticipation of a food reward in correct trials. The results demonstrate that corvids can volitionally control the release and onset of their vocalizations, suggesting that songbird vocalizations are under cognitive control and can be decoupled from affective states.

RevDate: 2020-02-25

Tringali A, Sherer DL, Cosgrove J, et al (2020)

Life history stage explains behavior in a social network before and during the early breeding season in a cooperatively breeding bird.

PeerJ, 8:e8302 pii:8302.

In species with stage-structured populations selection pressures may vary between different life history stages and result in stage-specific behaviors. We use life history stage to explain variation in the pre and early breeding season social behavior of a cooperatively breeding bird, the Florida scrub-jay (Aphelocoma coerulescens) using social network analysis. Life history stage explains much of the variation we observed in social network position. These differences are consistent with nearly 50 years of natural history observations and generally conform to a priori predictions about how individuals in different stages should behave to maximize their individual fitness. Where the results from the social network analysis differ from the a priori predictions suggest that social interactions between members of different groups are more important for breeders than previously thought. Our results emphasize the importance of accounting for life history stage in studies of individual social behavior.

RevDate: 2020-02-21
CmpDate: 2020-02-21

Rutz C, Hunt GR, JJH St Clair (2018)

Corvid Technologies: How Do New Caledonian Crows Get Their Tool Designs?.

Current biology : CB, 28(18):R1109-R1111.

Recent research shows that New Caledonian crows can incorporate information from researcher-made objects into objects they subsequently manufacture. This 'mental template matching' is one of several possible - mutually compatible - mechanisms for the cultural transmission of tool designs among wild crows.

RevDate: 2020-02-19
CmpDate: 2020-02-19

Taufique ST, Prabhat A, V Kumar (2019)

Light at night affects hippocampal and nidopallial cytoarchitecture: Implication for impairment of brain function in diurnal corvids.

Journal of experimental zoology. Part A, Ecological and integrative physiology, 331(2):149-156.

Our previous studies have shown that light at night (LAN) impaired cognitive performance and affected neurogenesis and neurochemistry in the cognition-associated brain regions, particularly the hippocampus (HP) and lateral caudal nidopallium (NCL) of Indian house crows (Corvus splendens). Here, we examined the cytoarchitecture and mapped out the morphology of neurons and glia-neuron density in HP and NCL regions of crows that were first entrained to 12-hr light (LL): 12-hr darkness (LD) and then exposed to the light regime in which 12-hr darkness was either replaced by daytime light (i.e., constant light, LL) or by dim light (i.e., dim light at night, dLAN), with controls continued on LD 12:12. Compared with LD, there was a significant decrease in the soma size, suggesting reduced neuronal plasticity without affecting the neuronal density of both HP and NCL of crows under LL and dLAN conditions. In parallel, we found a reduced number of glia cells and, hence, decreased glia-neuron ratio positively correlated with soma size in both, HP and NCL regions. These results for the first time demonstrate LAN-induced negative effects on the brain cytoarchitecture of a diurnal species and give insight for possible influence on the brain health and functions in animals including humans that might be inadvertently exposed to LAN in an emerging night-illuminated urban environment.

RevDate: 2020-02-13

Tryjanowski P, Hetman M, Czechowski P, et al (2020)

Birds Drinking Alcohol: Species and Relationship with People. A Review of Information from Scientific Literature and Social Media.

Animals : an open access journal from MDPI, 10(2): pii:ani10020270.

Ethanol is a natural by-product of the fermentation process of fruit sugars and is occasionally consumed by fruit-eating and tree sap drinking birds. Information on this form of alcohol consumption features in the scientific literature. However, as pets or as wild animals living close to humans in urban habitats, birds have increasing possibilities to consume alcohol from beverages, such as beer, wine or spirits. Some observations have been discussed in a light-hearted manner in mass media and social media, but without any generalization of why some bird species drink the beverages intentionally or unintentionally provided by humans. To check which species and in what circumstances birds drink alcohol and how this is evaluated by humans, we reviewed the scientific literature and analysed videos from YouTube. In total we found and analysed 8 scientific papers and 179 YouTube videos, from which we identified at least 55 species (in some cases not all birds were identified to species level), 11 in the scientific literature and 47 in videos. The distribution of these species over the avian phylogenetic tree suggests that the origin of this convergent behaviour is mainly by human influence. The two data sources differed in the species covered. Videos typically presented interactions of birds with human-provided alcoholic beverages, and were dominated by two groups of intelligent birds: parrots and corvids. The popularity of YouTube videos for a particular species was positively correlated with the general popularity of the species as measured by the number of hits (results listed) on Google. Human responses to the videos were generally very positive and we analysed how the responses were influenced by factors derived from viewing the videos. Moreover, YouTube videos also provide information on at least 47 new bird species not previously mentioned as using alcohol, and our results suggest that parrots in particular can be potentially good candidates for future restricted laboratory studies on the effect of ethanol on birds and their relationship with humans.

RevDate: 2020-01-18

Dutour M, AR Ridley (2020)

Females sing more often and at higher frequencies than males in Australian magpies.

Behavioural processes pii:S0376-6357(19)30305-5 [Epub ahead of print].

Birdsong is a particularly useful model for animal communication studies. However, current knowledge is derived mainly from the study of male song, and is therefore incomplete. Here, we investigated whether singing behaviour differs between sexes in the cooperatively breeding Western Australian magpie (Gymnorhina tibicen dorsalis). This subspecies lives in territorial groups, and in our population there is a female-biased sex ratio, which may lead to a high level of female-female competition for males. Observations of 94 magpies (54 females, 40 males) revealed that females sang more often than males. As bird song is a sexually multidimensional signal, we also studied amplitude and structure of the main territorial high-amplitude song in magpie; the carol. We found that females sing at the same amplitude as males, but that male and female carols exhibit differences in frequency. These results highlight the importance of studying female song and may change our perception regarding the evolution of sex-specific traits, given the primary focus on male singing as a sexually selected trait in the literature to date. The next step is to discover additional species in which females sing more than males in order to improve our currently incomplete understanding of the evolution of bird song.

RevDate: 2020-01-16

Vernouillet A, DM Kelly (2020)

Individual exploratory responses are not repeatable across time or context for four species of food-storing corvid.

Scientific reports, 10(1):394 pii:10.1038/s41598-019-56138-y.

Exploration is among one of the most studied of animal personality traits (i.e., individual-level behavioural responses repeatable across time and contexts). However, not all species show clear evidence of this personality trait, and this is particularly so for members of the Corvidae family. We assessed the exploratory behaviour of four food-caching corvid species: pinyon jays (Gymnorhinus cyanocephalus), Clark's nutcrackers (Nucifraga columbiana), California scrub jays (Aphelocoma californica), and black-billed magpies (Pica hudsonia). Contextual repeatability was assessed through examining behavioural measures during the Novel Environment task and the Novel Object task, whereas temporal repeatability was assessed by examining changes in these measures over repeated trials. Our results suggest that, for corvids, an individual's exploratory behaviour was not repeatable across contexts or over time. Hence, we found no evidence that exploration constitutes a personality trait for these species of corvid. We did find differences in exploratory behaviour, at a species level, that may be explained by relative reliance on cached food.

RevDate: 2020-01-15

Kövér L, Lengyel S, Takenaka M, et al (2019)

Why do zoos attract crows? A comparative study from Europe and Asia.

Ecology and evolution, 9(24):14465-14475 pii:ECE35881.

Crows have successfully colonized many cities, and urban zoos have been important in this process. To evaluate why zoos attract crows, we quantified crow numbers and behavior in three zoos in Europe (Debrecen, Edinburgh, Vienna) and one in Asia (Sapporo). Data were collected in 445 surveys over 297 days in summer 2014 and winter 2014-2015. We found that crow numbers were highest in Vienna, intermediate in Debrecen and Edinburgh and lowest in Sapporo, increased significantly from summer to winter (Debrecen, Edinburgh, Vienna), and from mornings to afternoons (Debrecen, Sapporo, Vienna), and were higher in sunny weather than in cloudy weather with precipitation and when visitor numbers were low (Debrecen, Vienna). The crows' use of natural food was highest in Vienna, intermediate in Edinburgh and Sapporo, and low in Debrecen. The use of anthropogenic food was high in Debrecen and Sapporo, where the availability of open grassy areas typically used by crows for natural foraging was low. In Sapporo, food availability was more limited than in other zoos, resulting in strong territoriality and few crows in summer, which decreased further in winter. Our study indicates that crows are primarily attracted to zoos by food availability and secondarily by breeding opportunities and that the relative importance of natural versus anthropogenic food sources may vary with zoo habitat structure. Our study draws attention to a previously overlooked role of zoos in urban biodiversity conservation. It may also provide useful information for the management of crow populations, if necessary, and for the planning of urban areas.

RevDate: 2020-01-14

Jiang S, Li Z, Cheng X, et al (2020)

The first pterosaur basihyal, shedding light on the evolution and function of pterosaur hyoid apparatuses.

PeerJ, 8:e8292 pii:8292.

The pterosaur is the first known vertebrate clade to achieve powered flight. Its hyoid apparatus shows a simplification similar to that of birds, although samples of the apparatus are rare, limiting the ability to make an accurate determination. In this study we reveal a new pterosaur specimen, including the first definite basihyal. Through the comparison of pterosaur hyoids, a trend has been discovered for the shortened hyoid relative to the length of the skull, indicating a diminished role of lingual retraction during the evolution of the pterosaur. The new material, possibly from a gallodactylid Gladocephaloideus, represents one of the least effective lingual retractions in all pterosaurs. Based on the structure of an elongated ceratobranchial and retroarticular process on mandibles, the function of the Y-shaped istiodactylid tongue bone is similar to those of scavenger crows rather than chameleons, which is consistent with the interpretation of the scavenging behavior of this taxon. More fossil samples are needed for further study on the function of other pterosaur hyoids.

RevDate: 2020-01-02

Abadi SH, Wacker DW, Newton JG, et al (2019)

Acoustic localization of crows in pre-roost aggregations.

The Journal of the Acoustical Society of America, 146(6):4664.

Crows are highly intelligent and social creatures. Each night during the non-breeding period, they gather on large pre-roost aggregations as they move towards their communal roost where they sleep. Crows make numerous and varied vocalizations on these pre-roost aggregations, but the purpose of these calls, and vocal communication in general, in these pre-roost aggregations is not fully understood. In this paper, an array of four microphones is used as a non-intrusive means to observe crow vocal behavior in pre-roost aggregations in the absence of human observers. By passively localizing animal vocalizations, the location of individuals can be monitored while simultaneously recording the acoustic structure and organization of their calls. Simulations and experiment are undertaken to study the performance of two time difference of arrival-based methods (hyperbolic location estimator and maximum likelihood estimator) for call localization. The effect of signal-to-noise ratio and uncertainty in measurement on the localization error is presented. By describing, modeling, and testing these techniques in this innovative context, the authors hope that researchers will employ the authors' approaches in future empirical studies to more fully understand crow vocal behavior.

RevDate: 2019-12-26

Ashton BJ, Thornton A, AR Ridley (2019)

Larger group sizes facilitate the emergence and spread of innovations in a group-living bird.

Animal behaviour, 158:1-7.

The benefits of group living have traditionally been attributed to risk dilution or the efficient exploitation of resources; individuals in social groups may therefore benefit from access to valuable information. If sociality facilitates access to information, then individuals in larger groups may be predicted to solve novel problems faster than individuals in smaller groups. Additionally, larger group sizes may facilitate the subsequent spread of innovations within animal groups, as has been proposed for human societies. We presented a novel foraging task (where a food reward could be accessed by pushing a self-shutting sliding door) to 16 groups of wild, cooperatively breeding Australian magpies, Cracticus tibicen dorsalis, ranging in size from two to 11 individuals. We found a nonlinear decline in the time taken for the innovative behaviour to emerge with increasing group size, and social information use facilitated the transmission of novel behaviour, with it spreading more quickly in larger than smaller groups. This study provides important evidence for a nonlinear relationship between group size and the emergence of innovation (and its subsequent transmission) in a wild population of animals. Further work investigating the scope and strength of group size-innovation relationships, and the mechanisms underpinning them, will help us understand the potential advantages of living in larger social groups.

RevDate: 2019-12-18

Ben-David A, Shamon H, Izhaki I, et al (2019)

Increased songbird nest depredation due to Aleppo pine (Pinus halepensis) encroachment in Mediterranean shrubland.

BMC ecology, 19(1):52 pii:10.1186/s12898-019-0270-8.

BACKGROUND: In recent decades, a decrease of passerine densities was documented in Mediterranean shrublands. At the same time, a widespread encroachment of Aleppo pines (Pinus halepensis) to Mediterranean shrubland occurred. Such changes in vegetation structure may affect passerine predator assemblage and densities, and in turn impact passerine densities. Depredation during the nesting season is an important factor to influence passerine population size. Understanding the effects of changes in vegetation structure (pine encroachment) on passerine nesting success is the main objective of this study. We do so by assessing the effects of Aleppo pine encroachment on Sardinian warbler (Sylvia melanocephala) nest depredation in Mediterranean shrublands. We examined direct and indirect predation pressures through a gradients of pine density, using four methods: (1) placing dummy nests; (2) acoustic monitoring of mobbing events; (3) direct observations on nest predation using cameras; and (4) observation of Eurasian jay (Garrulus glandarius) behaviour as indirect evidence of predation risk.

RESULTS: We found that Aleppo pine encroachment to Mediterranean shrublands increased nest predation by Eurasian jays. Nest predation was highest in mixed shrubland and pines. These areas are suitable for warblers but had high occurrence rate of Eurasian jays.

CONCLUSIONS: Encroaching pines directly increase activity of Eurasian jays in shrubland habitats, which reduced the nesting success of Sardinian warblers. These findings are supported by multiple methodologies, illustrating different predation pressures along a gradient of pine densities in natural shrublands. Management of Aleppo pine seedlings and removal of unwanted trees in natural shrubland might mitigate arrival and expansion of predators and decrease the predation pressure on passerine nests.

RevDate: 2019-12-17
CmpDate: 2019-12-12

Maron JL, Agrawal AA, DW Schemske (2019)

Plant-herbivore coevolution and plant speciation.

Ecology, 100(7):e02704.

More than five decades ago, Ehrlich and Raven proposed a revolutionary idea-that the evolution of novel plant defense could spur adaptive radiation in plants. Despite motivating much work on plant-herbivore coevolution and defense theory, Ehrlich and Raven never proposed a mechanism for their "escape and radiate" model. Recent intriguing mechanisms proposed by Marquis et al. include sympatric divergence, pleiotropic effects of plant defense traits on reproductive isolation, and strong postzygotic isolation, but these may not be general features of herbivore-mediated speciation. An alternate view is that herbivores may impose strong divergent selection on defenses in allopatric plant populations, with plant-herbivore coevolution driving local adaptation resulting in plant speciation. Building on these ideas, we propose three scenarios that consider the role of herbivores in plant speciation. These include (1) vicariance, subsequent coevolution within populations and adaptive divergence between geographically isolated populations, (2) colonization of a new habitat lacking effective herbivores followed by loss of defense and then re-evolution and coevolution of defense in response to novel herbivores, and (3) evolution of a new defense followed by range expansion, vicariance, and coevolution. We discuss the general role of coevolution in plant speciation and consider outstanding issues related to understanding: (1) the mechanisms behind cospeciation of plants and insects, (2) geographic variation in defense phenotypes, (3) how defensive traits and geography map on plant phylogenies, and (4) the role of herbivores in driving character displacement in defense phenotypes of related species in sympatry.

RevDate: 2019-12-17
CmpDate: 2019-12-17

Bugnyar T (2019)

Tool Use: New Caledonian Crows Engage in Mental Planning.

Current biology : CB, 29(6):R200-R202.

New Caledonian crows are able to flexibly use different tools in a sequence to retrieve food, whereby each step is out-of-sight of the others. Mental planning is thus not a human-specific trait.

RevDate: 2019-12-17
CmpDate: 2019-12-11

Bayern AMPV, Danel S, Auersperg AMI, et al (2018)

Compound tool construction by New Caledonian crows.

Scientific reports, 8(1):15676.

The construction of novel compound tools through assemblage of otherwise non-functional elements involves anticipation of the affordances of the tools to be built. Except for few observations in captive great apes, compound tool construction is unknown outside humans, and tool innovation appears late in human ontogeny. We report that habitually tool-using New Caledonian crows (Corvus moneduloides) can combine objects to construct novel compound tools. We presented 8 naïve crows with combinable elements too short to retrieve food targets. Four crows spontaneously combined elements to make functional tools, and did so conditionally on the position of food. One of them made 3- and 4-piece tools when required. In humans, individual innovation in compound tool construction is often claimed to be evolutionarily and mechanistically related to planning, complex task coordination, executive control, and even language. Our results are not accountable by direct reinforcement learning but corroborate that these crows possess highly flexible abilities that allow them to solve novel problems rapidly. The underlying cognitive processes however remain opaque for now. They probably include the species' typical propensity to use tools, their ability to judge affordances that make some objects usable as tools, and an ability to innovate perhaps through virtual, cognitive simulations.

RevDate: 2019-12-10
CmpDate: 2017-04-28

Kazemeini T, JS Fadardi (2016)

Executive Function: Comparing Bilingual and Monolingual Iranian University Students.

Journal of psycholinguistic research, 45(6):1315-1326.

The study aimed to examine whether Kurdish-Persian early Bilingual university students (EBL) and Persian Monolingual university students (ML) differ on tasks of executive function (EF). Thirty male EBL and 30 male ML students from Ferdowsi University of Mashhad completed a Persian Stroop Color-Word task (SCWT), Backward Digit Span Test (BDST), Raven Standard Progressive Matrices, and a demographic questionnaire. The results of an analysis of variance showed EBL students responded faster on the SCWT compared with ML students, suggesting an inhibition advantage for EBL students. Moreover, mean scores of BDST showed better performance of EBL students in working memory than ML students. These results provided evidence of advantaged EF among EBL and were consistent with the possibility that individuals who began speaking a second language (L2) earlier in childhood have greater advantages, due either to effects of acquiring an L2 earlier or to a longer duration of bilingual experience.

RevDate: 2019-12-12

Tätte K, Møller AP, R Mänd (2019)

Corvids exhibit dynamic risk assessment during escape.

Behavioural processes pii:S0376-6357(19)30346-8 [Epub ahead of print].

It is widely accepted that stationary prey are able to carefully assess the risk levels associated with an approaching predator to make informative decisions on when to escape. However, little is known about subsequent decision-making process. We set out to compare whether escape durations of three species of corvids differ depending on how a human observer (in the role of a predator) behaves after the escape has begun. When birds were being followed during escape, escape durations were the longest, escape trajectory was modified the most during escape, and a larger proportion of individuals changed from terrestrial to aerial escape strategy compared to observations where birds were not followed. Mean horizontal escape angle of ca 120º was also a potential indication that monitoring the threat is taken into account when deciding on the escape trajectory. While there were some differences between the behaviour of these three closely related species, the general patterns supported the notion that birds dynamically assess risk during escape to find an optimal balance between getting caught and spending too much time and energy on escaping. Further research using different predator-prey combinations or making comparisons between habitats could help understand the generality of our results.

RevDate: 2019-11-26

Klump BC (2019)

Of crows and tools.

Science (New York, N.Y.), 366(6468):965.

RevDate: 2019-11-29

Lambert CT, Sewall KB, LM Guillette (2019)

Questioning the developmental effects of group size on cognitive abilities.

Learning & behavior, 47(4):280-283.

Australian magpies living in larger social groups learned quicker and made fewer errors across four cognitive tasks compared with birds living in smaller social groups, and this pattern may be driven by a developmental effect associated with the cognitive demands of living in larger groups. While Smulders (2018, Learning and Behavior, 1-2, doi:10.3758/s13420-018-0335-0) questioned whether this group size-cognitive performance pattern was driven by motivation rather than cognitive abilities, we question whether there is truly evidence of a developmental effect and whether the relationship between group size and cognitive performance can be explained in other ways. We highlight potential alternative explanations for the relationship between group size and cognitive performance and highlight some of the theoretical issues underlying the developmental effects of group size on cognitive abilities.

RevDate: 2019-11-21

Ling H, Mclvor GE, Westley J, et al (2019)

Behavioural plasticity and the transition to order in jackdaw flocks.

Nature communications, 10(1):5174.

Collective behaviour is typically thought to arise from individuals following fixed interaction rules. The possibility that interaction rules may change under different circumstances has thus only rarely been investigated. Here we show that local interactions in flocks of wild jackdaws (Corvus monedula) vary drastically in different contexts, leading to distinct group-level properties. Jackdaws interact with a fixed number of neighbours (topological interactions) when traveling to roosts, but coordinate with neighbours based on spatial distance (metric interactions) during collective anti-predator mobbing events. Consequently, mobbing flocks exhibit a dramatic transition from disordered aggregations to ordered motion as group density increases, unlike transit flocks where order is independent of density. The relationship between group density and group order during this transition agrees well with a generic self-propelled particle model. Our results demonstrate plasticity in local interaction rules and have implications for both natural and artificial collective systems.

RevDate: 2019-11-26

Coomes JR, McIvor GE, A Thornton (2019)

Correction to 'Evidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula)'.

Biology letters, 15(11):20190740.

RevDate: 2019-11-14

Holtmann B, Buskas J, Steele M, et al (2019)

Dominance relationships and coalitionary aggression against conspecifics in female carrion crows.

Scientific reports, 9(1):15922.

Cooperation is a prevailing feature of many animal systems. Coalitionary aggression, where a group of individuals engages in coordinated behaviour to the detriment of conspecific targets, is a form of cooperation involving complex social interactions. To date, evidence has been dominated by studies in humans and other primates with a clear bias towards studies of male-male coalitions. We here characterize coalitionary aggression behaviour in a group of female carrion crows consisting of recruitment, coordinated chase, and attack. The individual of highest social rank liaised with the second most dominant individual to engage in coordinated chase and attack of a lower ranked crow on several occasions. Despite active intervention by the third most highly ranked individual opposing the offenders, the attack finally resulted in the death of the victim. All individuals were unrelated, of the same sex, and naïve to the behaviour excluding kinship, reproduction, and social learning as possible drivers. Instead, the coalition may reflect a strategy of the dominant individual to secure long-term social benefits. Overall, the study provides evidence that members of the crow family engage in coordinated alliances directed against conspecifics as a possible means to manipulate their social environment.

RevDate: 2019-11-14

Ling H, Mclvor GE, Westley J, et al (2019)

Collective turns in jackdaw flocks: kinematics and information transfer.

Journal of the Royal Society, Interface, 16(159):20190450.

The rapid, cohesive turns of bird flocks are one of the most vivid examples of collective behaviour in nature, and have attracted much research. Three-dimensional imaging techniques now allow us to characterize the kinematics of turning and their group-level consequences in precise detail. We measured the kinematics of flocks of wild jackdaws executing collective turns in two contexts: during transit to roosts and anti-predator mobbing. All flocks reduced their speed during turns, probably because of constraints on individual flight capability. Turn rates increased with the angle of the turn so that the time to complete turns remained constant. We also find that context may alter where turns are initiated in the flocks: for transit flocks in the absence of predators, initiators were located throughout the flocks, but for mobbing flocks with a fixed ground-based predator, they were always located at the front. Moreover, in some transit flocks, initiators were far apart from each other, potentially because of the existence of subgroups and variation in individual interaction ranges. Finally, we find that as the group size increased the information transfer speed initially increased, but rapidly saturated to a constant value. Our results highlight previously unrecognized complexity in turning kinematics and information transfer in social animals.

RevDate: 2019-10-16

El-Sayed AK, S Hassan (2019)

Gross morphological features of the air sacs of the hooded crow (Corvus cornix).

Anatomia, histologia, embryologia [Epub ahead of print].

Air sacs are considered to be one of the controlling factors of bird behaviour and habits in addition to their roles in ventilation, regulating body temperature, swimming and flight. As a scavenger and an omnivorous flight bird, air sacs of the hooded crow were the focus of this study. Eight healthy, adult hooded crows were used to examine the morphological characteristics of the air sacs, which were examined grossly and with latex and cast preparations. In general, the morphological overview of the hooded crow air sacs is similar to other avian species. We observed nine air sacs; four paired sacs (cervical, cranial thoracic, caudal thoracic and abdominal air sacs) and one unpaired sac; the clavicular air sac. The cervical air sac communicated to the lung through the medioventral bronchus and had three diverticula; intermuscular, subscapular and subcutaneous. The clavicular air sac communicated with lung through the medioventral bronchus and had subscapular, axillary, humeral, subpectoral and sternal diverticula. The cranial and caudal thoracic air sacs were communicated with lung through the lateroventral bronchi and the both sacs did not have any diverticula. The abdominal air sacs were posterior to the caudal thoracic air sacs. The left abdominal sac was the largest air sac. The right and left abdominal sacs gave off branches to diverticula that pneumatized synsacrum. The abdominal air sacs gave off femoral diverticula behind the hip joint as well as perirenal diverticula.

RevDate: 2019-10-07

Vanhooland LC, Bugnyar T, JJM Massen (2019)

Crows (Corvus corone ssp.) check contingency in a mirror yet fail the mirror-mark test.

Journal of comparative psychology (Washington, D.C. : 1983) pii:2019-59593-001 [Epub ahead of print].

Mirror reflections can elicit various behavioral responses ranging from social behavior, which suggests that an animal treats its own reflection as a conspecific, to mirror-guided self-directed behaviors, which appears to be an indication for mirror self-recognition (MSR). MSR is scarcely spread in the animal kingdom. Until recently, only great apes, dolphins, and elephants had successfully passed this test. The range of convergence was, however, expanded by an avian species, the Eurasian magpie (Pica pica). Efforts to find MSR in other corvid species have so far failed, and with only a few studies conducted, the cause of these discrepancies is difficult to identify. In the present study, we examined the responses to mirrors and the ability of MSR in hitherto untested species: the carrion and hooded crows (Corvus corone ssp.). These crows showed a pronounced and lasting interest in the mirror; unlike many species, they did not exhibit social behaviors on their first encounters but immediately started investigating the mirror. Some crows showed contingent behaviors in front of the mirror, but none of the crows showed significant mirror-guided self-directed behaviors nor mark-directed behavior during the subsequent mark test. This lack of mark-directed behavior could not be explained by a lack of interest in the mirror nor in the mark. These findings could indicate that crows lack a concept of self, or the need for other means of investigating self-recognition and self-awareness in avian species. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

RevDate: 2019-12-10

Coomes JR, McIvor GE, A Thornton (2019)

Evidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula).

Biology letters, 15(10):20190380.

Collective responses to threats occur throughout the animal kingdom but little is known about the cognitive processes underpinning them. Antipredator mobbing is one such response. Approaching a predator may be highly risky, but the individual risk declines and the likelihood of repelling the predator increases in larger mobbing groups. The ability to appraise the number of conspecifics involved in a mobbing event could therefore facilitate strategic decisions about whether to join. Mobs are commonly initiated by recruitment calls, which may provide valuable information to guide decision-making. We tested whether the number of wild jackdaws responding to recruitment calls was influenced by the number of callers. As predicted, playbacks simulating three or five callers tended to recruit more individuals than playbacks of one caller. Recruitment also substantially increased if recruits themselves produced calls. These results suggest that jackdaws use individual vocal discrimination to assess the number of conspecifics involved in initiating mobbing events, and use this information to guide their responses. Our results show support for the use of numerical assessment in antipredator mobbing responses and highlight the need for a greater understanding of the cognitive processes involved in collective behaviour.

RevDate: 2019-10-23

Forti LR, Haddad CFB, Leite F, et al (2019)

Notes on vocalizations of Brazilian amphibians IV: advertisement calls of 20 Atlantic Forest frog species.

PeerJ, 7:e7612.

Bioacoustics is a powerful tool used for anuran species diagnoses, given that advertisement calls are signals related to specific recognition and mate attraction. Thus, call descriptions can support species taxonomy. In spite of that, call descriptions are lacking for many species, delaying advances in biodiversity research. Here, we describe the advertisement calls of 20 anuran species from the Brazilian Atlantic Forest. We accessed 50 digital recordings deposited in the Fonoteca Neotropical Jacques Vielliard. Acoustic analyses were carried out in the software Raven pro 1.5. We provide a general comparison of call structure among species inside taxonomic groups and genera. The vocalizations described here belong to poorly known species, which are representatives of six families: Brachycephalidae, Bufonidae, Ceratophryidae, Cycloramphidae, Hylidae, and Phyllomedusidae. Despite this, still there are 163 species of anurans from Atlantic Forest with calls not formally described. Our work represents an important step in providing data for a taxonomic perspective and improving the knowledge of the Atlantic Forest anuran diversity.

RevDate: 2019-10-26

Blasco R, Rosell J, Sánchez-Marco A, et al (2019)

Feathers and food: Human-bird interactions at Middle Pleistocene Qesem Cave, Israel.

Journal of human evolution, 136:102653.

The presence of fast-moving small game in the Paleolithic archaeological faunal record has long been considered a key variable to assess fundamental aspects of human behavior and subsistence. Birds occupy a prominent place in this debate not only due to their small size and to the difficulties in capturing them (essentially due to their ability to fly and their elusiveness), but also due to their possible role in the symbolic array in regard to non-nutritional elements (feathers, talons, etc.) and as reflectors of complex human-world relationships. In this study, we attempt to contribute to this topic by presenting taphonomical data of bird specimens from Qesem Cave (Israel), dated between 420 and 200 ka. Human-induced damage, including cut marks, peeling and human gnawing, has been identified on wing bones of Cygnus sp., Columba sp., Corvus ruficollis and Sturnus sp. Our evidence suggests that avian exploitation was not limited to food only-either to complement the human diet or as occasional food item-but also presumably for the use of feathers. While the consumption of birds as a dietary source seems to be evident as early as the Early Pleistocene, the non-alimentary use of inedible elements, such as feathers and talons, appears to be a practice from the Middle Paleolithic onwards. We argue that the combined nutritional and symbolic use of birds is one characteristic of the new mode of adaptation practiced already by the late Lower Paleolithic Acheulo-Yabrudian hominins in the Levant starting 400 ka. The Qesem findings point to the possible emergence of new cognitive and behavioral skills, which are followed in later periods in the Old World. Finally, we discuss the possible ontological and cosmological significance of human-bird interactions to illuminate our hypothesis regarding the emergence of a new perception of human relationships with the world as an integral part of the new Acheulo-Yabrudian mode of adaptation.

RevDate: 2019-09-13

Shekhawat S, A Saxena (2019)

Development and applications of an intelligent crow search algorithm based on opposition based learning.

ISA transactions pii:S0019-0578(19)30419-7 [Epub ahead of print].

Metaheuristics are proven beneficial tools for solving complex, hard optimization problems. Recently, a plethora of work has been reported on bio inspired optimization algorithms. These algorithms are mimicry of behavior of animals, plants and processes into mathematical paradigms. With these developments, a new entrant in this group is Crow Search Algorithm (CSA). CSA is based on the strategic behavior of crows while searching food, thievery and chasing behavior. This algorithm sometimes suffers with local minima stagnation and unbalance exploration and exploitation phases. To overcome this problem, a cosine function is proposed first, to accelerate the exploration and retard the exploitation process with due course of the iterative process. Secondly the opposition based learning concept is incorporated for enhancing the exploration virtue of CSA. The evolved variant with the inculcation of these two concepts is named as Intelligent Crow Search Algorithm (ICSA). The algorithm is benchmarked on two benchmark function sets, one is the set of 23 standard test functions and another is set of latest benchmark function CEC-2017. Further, the applicability of this variant is tested over structural design problem, frequency wave synthesis problem and Model Order Reduction (MOR). Results reveal that ICSA exhibits competitive performance on benchmarks and real applications when compared with some contemporary optimizers.

RevDate: 2019-09-29

Vonk J (2019)

Emotional contagion or sensitivity to behavior in ravens?.

Proceedings of the National Academy of Sciences of the United States of America, 116(37):18168.

RevDate: 2019-08-20

McCoy DE, Schiestl M, Neilands P, et al (2019)

New Caledonian Crows Behave Optimistically after Using Tools.

Current biology : CB, 29(16):2737-2742.e3.

Are complex, species-specific behaviors in animals reinforced by material reward alone or do they also induce positive emotions? Many adaptive human behaviors are intrinsically motivated: they not only improve our material outcomes, but improve our affect as well [1-8]. Work to date on animal optimism, as an indicator of positive affect, has generally focused on how animals react to change in their circumstances, such as when their environment is enriched [9-14] or they are manipulated by humans [15-23], rather than whether complex actions improve emotional state. Here, we show that wild New Caledonian crows are optimistic after tool use, a complex, species-specific behavior. We further demonstrate that this finding cannot be explained by the crows needing to put more effort into gaining food. Our findings therefore raise the possibility that intrinsic motivation (enjoyment) may be a fundamental proximate cause in the evolution of tool use and other complex behaviors. VIDEO ABSTRACT.

RevDate: 2019-07-22

Lazareva OF, Gould K, Linert J, et al (2019)

Smaller on the left? Flexible association between space and magnitude in pigeons (Columba livia) and blue jays (Cyanocitta cristata).

Journal of comparative psychology (Washington, D.C. : 1983) pii:2019-41901-001 [Epub ahead of print].

Humans and other apes represent magnitudes spatially, demonstrated by their responding faster and more accurately to one side of space when presented with small quantities and to the other side of space when presented with large quantities. This representation is flexible and shows substantial variability between cultural groups in humans and between and within individuals in great apes. In contrast, recent findings suggest that chicks show a spatial representation of magnitude that is highly lateralized and inflexible, implying a qualitatively different underlying representation than in primates. Using methods similar to those used with great apes and humans, we trained adult domestic pigeons (Columba livia) and blue jays (Cyanocitta cristata) to select the smaller (or larger) of two nonadjacent quantity arrays; later, this task was reversed. At test, birds were presented with novel probe pairs consisting of adjacent quantity pairs (e.g., 2 vs. 3). Both species showed robust evidence for a flexible spatial representation of magnitude with considerable individual variability in the orientation of this representation. These results are not consistent with an inflexible, lateralized, left-to-right representation of magnitude in birds, but are consistent with the flexible spatial representation of magnitude observed in apes and humans. We conclude that the tendency to organize quantities spatially may be a fundamental and evolutionarily ancient feature of cognition that is widespread among vertebrates. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

RevDate: 2019-07-04

Vonk J (2019)

Sticks and stones: Associative learning alone?.

Learning & behavior pii:10.3758/s13420-019-00387-4 [Epub ahead of print].

Gruber et al. (Current Biology, 29, 686-692, 2019) report that New Caledonian crows engage in mental representation to solve a problem involving a tool. Although the crows' success is impressive, an associative account of their behavior calls into question the extent to which the data reflect representation of future states.

RevDate: 2019-07-30

Ling H, Mclvor GE, van der Vaart K, et al (2019)

Local interactions and their group-level consequences in flocking jackdaws.

Proceedings. Biological sciences, 286(1906):20190865.

As one of nature's most striking examples of collective behaviour, bird flocks have attracted extensive research. However, we still lack an understanding of the attractive and repulsive forces that govern interactions between individuals within flocks and how these forces influence neighbours' relative positions and ultimately determine the shape of flocks. We address these issues by analysing the three-dimensional movements of wild jackdaws (Corvus monedula) in flocks containing 2-338 individuals. We quantify the social interaction forces in large, airborne flocks and find that these forces are highly anisotropic. The long-range attraction in the direction perpendicular to the movement direction is stronger than that along it, and the short-range repulsion is generated mainly by turning rather than changing speed. We explain this phenomenon by considering wingbeat frequency and the change in kinetic and gravitational potential energy during flight, and find that changing the direction of movement is less energetically costly than adjusting speed for birds. Furthermore, our data show that collision avoidance by turning can alter local neighbour distributions and ultimately change the group shape. Our results illustrate the macroscopic consequences of anisotropic interaction forces in bird flocks, and help to draw links between group structure, local interactions and the biophysics of animal locomotion.

RevDate: 2019-10-12

Federspiel IG, Boeckle M, von Bayern AMP, et al (2019)

Exploring individual and social learning in jackdaws (Corvus monedula).

Learning & behavior, 47(3):258-270.

Information about novel environments or foods can be gathered via individual or social learning. Whereas individual learning is assumed to be more costly and less effective than social learning, it also yields more detailed information. Juveniles are often found to be more explorative than adults. Still under the protection of their parents, this allows them to sample their environment in preparation for later in life. We tested individual and social learning in jackdaws (Corvus monedula) of different age groups in a semi-natural group setting. Juvenile and adult jackdaws differed in their learning propensity. Juveniles spent more time at the test apparatus, were more explorative, and caused the apparatus to open. Almost all the openings at the apparatus matched the demonstrated method. As more observers became available, the juveniles could observe each other. Individuals preferentially watched successful conspecifics and those they could scrounge food from. Lower-ranking individuals tended to watch higher ranking ones; higher ranking individuals preferentially watched conspecifics of similar rank. The control group did not manipulate the apparatus. Due to the lack of this baseline, it was difficult to determine for certain whether the opening technique was acquired via individual or social learning. We conclude that if social learning played a role, the underlying mechanism was most likely local or stimulus enhancement. It is, however, more parsimonious to assume that juveniles were more explorative than adults, and that their opening technique was potentially easier to acquire than the one demonstrated to adults.

RevDate: 2019-11-20

Adriaense JEC, Martin JS, Schiestl M, et al (2019)

Negative emotional contagion and cognitive bias in common ravens (Corvus corax).

Proceedings of the National Academy of Sciences of the United States of America, 116(23):11547-11552.

Emotional contagion is described as an emotional state matching between subjects, and has been suggested to facilitate communication and coordination in complex social groups. Empirical studies typically focus on the measurement of behavioral contagion and emotional arousal, yet, while highly important, such an approach often disregards an additional evaluation of the underlying emotional valence. Here, we studied emotional contagion in ravens by applying a judgment bias paradigm to assess emotional valence. We experimentally manipulated positive and negative affective states in demonstrator ravens, to which they responded with increased attention and interest in the positive condition, as well as increased redirected behavior and a left-eye lateralization in the negative condition. During this emotion manipulation, another raven observed the demonstrator's behavior, and we used a bias paradigm to assess the emotional valence of the observer to determine whether emotional contagion had occurred. Observers showed a pessimism bias toward the presented ambiguous stimuli after perceiving demonstrators in a negative state, indicating emotional state matching based on the demonstrators' behavioral cues and confirming our prediction of negative emotional contagion. We did not find any judgment bias in the positive condition. This result critically expands upon observational studies of contagious play in ravens, providing experimental evidence that emotional contagion is present not only in mammalian but also in avian species. Importantly, this finding also acts as a stepping stone toward understanding the evolution of empathy, as this essential social skill may have emerged across these taxa in response to similar socioecological challenges.


RJR Experience and Expertise


Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.


Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.


Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.


Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.


While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.


Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.


Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.


Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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This is a must read book for anyone with an interest in invasion biology. The full title of the book lays out the author's premise — The New Wild: Why Invasive Species Will Be Nature's Salvation. Not only is species movement not bad for ecosystems, it is the way that ecosystems respond to perturbation — it is the way ecosystems heal. Even if you are one of those who is absolutely convinced that invasive species are actually "a blight, pollution, an epidemic, or a cancer on nature", you should read this book to clarify your own thinking. True scientific understanding never comes from just interacting with those with whom you already agree. R. Robbins

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Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

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