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Bibliography on: Corvids: Behavior

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Robert J. Robbins is a biologist, an educator, a science administrator, a publisher, an information technologist, and an IT leader and manager who specializes in advancing biomedical knowledge and supporting education through the application of information technology. More About:  RJR | OUR TEAM | OUR SERVICES | THIS WEBSITE

RJR: Recommended Bibliography 16 Nov 2019 at 01:35 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: 2019-11-15

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

Behavioural plasticity and the transition to order in jackdaw flocks.

Nature communications, 10(1):5174 pii:10.1038/s41467-019-13281-4.

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: 2019-11-14
CmpDate: 2019-11-14

Taufique SKT, Prabhat A, V Kumar (2018)

Illuminated night alters hippocampal gene expressions and induces depressive-like responses in diurnal corvids.

The European journal of neuroscience, 48(9):3005-3018.

Artificial light at night induces circadian disruptions and causes cognitive impairment and mood disorders; yet very little is known about the neural and molecular correlates of these effects in diurnal animals. We manipulated the night environment and examined cellular and molecular changes in hippocampus, the brain region involved in cognition and mood, of Indian house crows (Corvus splendens) exposed to 12 hr light (150 lux): 12 hr darkness (0 lux). Diurnal corvids are an ideal model species with cognitive abilities at par with mammals. Dim light (6 lux) at night (dLAN) altered daily activity:rest pattern, reduced sleep, and induced depressive-like responses (decreased eating and self-grooming, self-mutilation, and reduced novel object exploration); return to an absolute dark night reversed these negative effects. dLAN suppressed nocturnal melatonin levels; however, diurnal corticosterone levels were unaffected. Concomitant reduction of immunoreactivity for DCX and BDNF suggested dLAN-induced suppression of hippocampal neurogenesis and compromised neuronal health. dLAN also negatively influenced hippocampal expression of genes associated with depressive-like responses (bdnf, il-1β, tnfr1, nr4a2), but not of those associated with neuronal plasticity (egr1, creb, syngap, syn2, grin2a, grin2b), cellular oxidative stress (gst, sod3, cat1) and neuronal death (caspase2, caspase3, foxo3). Furthermore, we envisaged the role of BDNF and showed epigenetic modification of bdnf gene by decreased histone H3 acetylation and increased hdac4 expression under dLAN. These results demonstrate transcriptional and epigenetic bases of dLAN-induced negative effects in diurnal crows, and provide insights into the risks of exposure to illuminated nights to animals including humans in an urban setting.

RevDate: 2019-11-06

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: 2019-11-05

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 pii:10.1038/s41598-019-52177-7.

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: 2019-10-23

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: 2019-10-23
CmpDate: 2019-10-23

Klump BC, Cantat M, C Rutz (2019)

Raw-material selectivity in hook-tool-crafting New Caledonian crows.

Biology letters, 15(2):20180836.

Animals that manufacture foraging tools face the challenge of identifying suitable raw materials among a multitude of options. New Caledonian crows exhibit strong population-specific material preferences for the manufacture of hooked stick tools, but it is unknown how they identify their favourite plants. We investigated experimentally whether crows pay attention to the stems of plants (from which the tools are made) and/or their leaves (which are usually discarded during manufacture but may enable rapid and reliable species identification at a distance). Subjects were highly selective in choice trials with multiple plant species. Two additional treatments with experimental leaf-stem combinations revealed that birds can identify their preferred plant species by its stems alone, and possibly also its leaves. These findings encourage future experiments that investigate whether New Caledonian crows attend to features of the stem that are required for the production of efficient hooked stick tools. Our study provides one of the most detailed assessments to date of how non-human animals identify raw materials for tool manufacture.

RevDate: 2019-10-22
CmpDate: 2019-10-21

Jelbert SA, Hosking RJ, Taylor AH, et al (2018)

Mental template matching is a potential cultural transmission mechanism for New Caledonian crow tool manufacturing traditions.

Scientific reports, 8(1):8956.

Cumulative cultural evolution occurs when social traditions accumulate improvements over time. In humans cumulative cultural evolution is thought to depend on a unique suite of cognitive abilities, including teaching, language and imitation. Tool-making New Caledonian crows show some hallmarks of cumulative culture; but this claim is contentious, in part because these birds do not appear to imitate. One alternative hypothesis is that crows' tool designs could be culturally transmitted through a process of mental template matching. That is, individuals could use or observe conspecifics' tools, form a mental template of a particular tool design, and then reproduce this in their own manufacture - a process analogous to birdsong learning. Here, we provide the first evidence supporting this hypothesis, by demonstrating that New Caledonian crows have the cognitive capacity for mental template matching. Using a novel manufacture paradigm, crows were first trained to drop paper into a vending machine to retrieve rewards. They later learnt that only items of a particular size (large or small templates) were rewarded. At test, despite being rewarded at random, and with no physical templates present, crows manufactured items that were more similar in size to previously rewarded, than unrewarded, templates. Our results provide the first evidence that this cognitive ability may underpin the transmission of New Caledonian crows' natural tool designs.

RevDate: 2019-10-18
CmpDate: 2019-10-18

Hirst RB, Conaboy C, Vaughn D, et al (2018)

The "Jay-Dar" Phenomenon: Individuals Discriminate Cannabis Users from Nonusers Based Upon a Photograph.

Substance use & misuse, 53(14):2359-2367.

OBJECTIVE: With increasing legalization of medicinal and recreational cannabis, use is on the rise. Research suggests individuals may be able to guess cannabis user status based upon appearance; however, these findings utilized a small sample of photographs that was not balanced on user status or gender. Further, no studies examined whether raters with cannabis experience are better at judging others' cannabis use, or what physical features they use to make these judgments. This study explored these factors using a larger, balanced photograph database.

METHOD: An American sample (n = 249, 48.6% female, mean age = 35.19 years) rated 36 photographs (18 cannabis users, 18 nonusers) balanced on gender and age on the likelihood that the photographed individuals use cannabis, producing 8964 ratings. Respondents also reported physical features considered in their ratings, as well as their own cannabis use history.

RESULTS: As hypothesized, photographs of users received higher ratings on the Marijuana Use Likelihood Index relative to nonusers. Further, results revealed a gender by rater user status interaction, indicating that raters with no previous cannabis experience rated males higher than females, while raters with cannabis experience did not demonstrate this rating discrepancy. Cannabis use explained over 9% of the variance in ratings across all photographs.

CONCLUSIONS: Results suggest individuals do rate cannabis users as more likely to be users, relative to nonusers, based upon appearance alone. These findings have important implications, not only for research on chronic cannabis use effects, but also for social and achievement factors such as potential stigma.

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: 2019-10-01

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: 2019-10-01
CmpDate: 2019-10-01

Bose A, Dürr T, Klenke RA, et al (2018)

Collision sensitive niche profile of the worst affected bird-groups at wind turbine structures in the Federal State of Brandenburg, Germany.

Scientific reports, 8(1):3777.

Biodiversity-related impacts at wind energy facilities have increasingly become a cause of conservation concern, central issue being the collision of birds. Utilizing spatial information of their carcass detections at wind turbines (WTs), we quantified the detections in relation to the metric distances of the respective turbines to different land-use types. We used ecological niche factor analysis (ENFA) to identify combinations of land-use distances with respect to the spatial allocation of WTs that led to higher proportions of collisions among the worst affected bird-groups: Buntings, Crows, Larks, Pigeons and Raptors. We also assessed their respective similarities to the collision phenomenon by checking for overlaps amongst their distance combinations. Crows and Larks showed the narrowest "collision sensitive niche"; a part of ecological niche under higher risk of collisions with turbines, followed by that of Buntings and Pigeons. Raptors had the broadest niche showing significant overlaps with the collision sensitive niches of the other groups. This can probably be attributed to their larger home range combined with their hunting affinities to open landscapes. Identification of collision sensitive niches could be a powerful tool for landscape planning; helping avoid regions with higher risks of collisions for turbine allocations and thus protecting sensitive bird populations.

RevDate: 2019-09-30

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 pii:7612.

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: 2019-09-26
CmpDate: 2019-09-26

Scott AB, Phalen D, Hernandez-Jover M, et al (2018)

Wildlife Presence and Interactions with Chickens on Australian Commercial Chicken Farms Assessed by Camera Traps.

Avian diseases, 62(1):65-72.

The types of wildlife and the frequency of their visits to commercial chicken farms in Australia were assessed using infrared and motion-sensing camera traps. Cameras were set up on 14 free-range layer farms, three cage layer farms, two barn layer farms, five non-free-range meat chicken farms, and six free-range meat chicken farms in the Sydney basin region and South East Queensland. Wildlife visits were found on every farm type and were most frequent on cage layer farms (73%), followed by free-range layer farms (15%). The common mynah (Acridotheres tristis) was the most frequent wildlife visitor in the study (23.9%), followed by corvids (22.9%) and Columbiformes (7.5%). Most wildlife visits occurred during the day from 6 am to 6 pm (85%). There were infrequent observations of direct contact between chickens and wildlife, suggesting the indirect route of pathogen transfer may be more significant. The level of biosecurity on the farm is suggested to impact the frequency of wildlife visits more so than the farm type.

RevDate: 2019-09-22

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 pii:S0047-2484(19)30129-0 [Epub ahead of print].

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: 2019-09-19
CmpDate: 2019-09-19

Wagener L, Loconsole M, Ditz HM, et al (2018)

Neurons in the Endbrain of Numerically Naive Crows Spontaneously Encode Visual Numerosity.

Current biology : CB, 28(7):1090-1094.e4.

Endowed with an elaborate cerebral cortex, humans and other primates can assess the number of items in a set, or numerosity, from birth on [1] and without being trained [2]. Whether spontaneous numerosity extraction is a unique feat of the mammalian cerebral cortex [3-7] or rather an adaptive property that can be found in differently designed and independently evolved neural substrates, such as the avian enbrain [8], is unknown. To address this question, we recorded single-cell activity from the nidopallium caudolaterale (NCL), a high-level avian association brain area [9-11], of numerically naive crows. We found that a proportion of NCL neurons were spontaneously responsive to numerosity and tuned to the number of items, even though the crows were never trained to assess numerical quantity. Our data show that numerosity-selective neuronal responses are spontaneously present in the distinct endbrains of diverge vertebrate taxa. This seemingly hard-wired property of the avian endbrain to extract numerical quantity explains how birds in the wild, or right after hatching, can exploit numerical cues when making foraging or social decisions. It suggests that endbrain circuitries that evolved based on convergent evolution, such as the avian endbrain, give rise to the same numerosity code.

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: 2019-08-21

Vonk J (2019)

Emotional contagion or sensitivity to behavior in ravens?.

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: 2019-08-22

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: 2019-06-18

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.

RevDate: 2019-05-20

Miller R, Boeckle M, Jelbert SA, et al (2019)

Self-control in crows, parrots and nonhuman primates.

Wiley interdisciplinary reviews. Cognitive science [Epub ahead of print].

Self-control is critical for both humans and nonhuman animals because it underlies complex cognitive abilities, such as decision-making and future planning, enabling goal-directed behavior. For instance, it is positively associated with social competence and life success measures in humans. We present the first review of delay of gratification as a measure of self-control in nonhuman primates, corvids (crow family) and psittacines (parrot order): disparate groups that show comparable advanced cognitive abilities and similar socio-ecological factors. We compare delay of gratification performance and identify key issues and outstanding areas for future research, including finding the best measures and drivers of delayed gratification. Our review therefore contributes to our understanding of both delayed gratification as a measure of self-control and of complex cognition in animals. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Psychology > Comparative Psychology.

RevDate: 2019-06-28

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

Costs and benefits of social relationships in the collective motion of bird flocks.

Nature ecology & evolution, 3(6):943-948.

Current understanding of collective behaviour in nature is based largely on models that assume that identical agents obey the same interaction rules, but in reality interactions may be influenced by social relationships among group members. Here, we show that social relationships transform local interactions and collective dynamics. We tracked individuals' three-dimensional trajectories within flocks of jackdaws, a species that forms lifelong pair-bonds. Reflecting this social system, we find that flocks contain internal sub-structure, with discrete pairs of individuals tied together by spring-like effective forces. Within flocks, paired birds interacted with fewer neighbours than unpaired birds and flapped their wings more slowly, which may result in energy savings. However, flocks with more paired birds had shorter correlation lengths, which is likely to inhibit efficient information transfer through the flock. Similar changes to group properties emerge naturally from a generic self-propelled particle model. These results reveal a critical tension between individual- and group-level benefits during collective behaviour in species with differentiated social relationships, and have major evolutionary and cognitive implications.

RevDate: 2019-04-11

Jelbert SA, Miller R, Schiestl M, et al (2019)

New Caledonian crows infer the weight of objects from observing their movements in a breeze.

Proceedings. Biological sciences, 286(1894):20182332.

Humans use a variety of cues to infer an object's weight, including how easily objects can be moved. For example, if we observe an object being blown down the street by the wind, we can infer that it is light. Here, we tested whether New Caledonian crows make this type of inference. After training that only one type of object (either light or heavy) was rewarded when dropped into a food dispenser, birds observed pairs of novel objects (one light and one heavy) suspended from strings in front of an electric fan. The fan was either on-creating a breeze which buffeted the light, but not the heavy, object-or off, leaving both objects stationary. In subsequent test trials, birds could drop one, or both, of the novel objects into the food dispenser. Despite having no opportunity to handle these objects prior to testing, birds touched the correct object (light or heavy) first in 73% of experimental trials, and were at chance in control trials. Our results suggest that birds used pre-existing knowledge about the behaviour exhibited by differently weighted objects in the wind to infer their weight, using this information to guide their choices.

RevDate: 2019-04-03

Boucherie PH, Loretto MC, Massen JJM, et al (2019)

What constitutes "social complexity" and "social intelligence" in birds? Lessons from ravens.

Behavioral ecology and sociobiology, 73(1):12.

In the last decades, the assumption that complex social life is cognitively challenging, and thus can drive mental evolution, has received much support from empirical studies in nonhuman primates. While extending the scope to other mammals and birds, different views have been adopted on what constitutes social complexity and which specific cognitive skills are selected for. Notably, many avian species form "open" groups as non-breeders (i.e., seasonally and before sexual maturity) that have been largely ignored as potential sources of social complexity. Reviewing 30 years of research on ravens, we illustrate the socio-ecological conditions faced by these birds as non-breeders and discuss how these relate to their socio-cognitive skills. We argue that the non-breeding period is key to understand raven social life and, to a larger extent, avian social life in general. We furthermore emphasize how the combination of the large-scale perspective (defining social system components: e.g., social organization, mating system) and the individual-scale perspective on social systems allows to better capture the complete set of social challenges experienced by individuals throughout their life, ultimately resulting on a more comprehensive understanding of species' social complexity.

RevDate: 2019-05-24

Matsui H, EI Izawa (2019)

Control of bill-grasping aperture with varying food size in crows.

Neuroreport, 30(7):522-525.

Grasping movement in primates is known to be a visually guided behavior and the aperture of hand opening is adjusted to the target size on the basis of visual information. The analogous behavior can be found in birds, called 'pecking', consisting of head-reaching and bill-grasping. Bill-grasping has been investigated mainly in pigeons and an aperture adjustment as seen in primates has been reported. This study focused on kinematics of pecking in crows, known to possess dexterous visuomotor skills, to examine whether crows adjust the grasping aperture to food diameter with a kinematic mechanism similar to that in pigeons. The pecking at a small piece of food was video recorded to analyze the grasping aperture. The results showed that the grasping aperture was proportional to food diameter. Kinematic analysis showed that the aperture adjustment was mediated by grasping velocity and grasping duration, which is consistent with the findings of previous research on pecking in pigeons. However, the relative contribution of grasping velocity was much higher than that of grasping duration. Our findings suggest the different sensorimotor mechanisms to control bill-grasping between the avian species with different foraging ecology.

RevDate: 2019-03-29

Policht R, Hart V, Goncharov D, et al (2019)

Vocal recognition of a nest-predator in black grouse.

PeerJ, 7:e6533 pii:6533.

Corvids count among the important predators of bird nests. They are vocal animals and one can expect that birds threatened by their predation, such as black grouse, are sensitive to and recognize their calls. Within the framework of field studies, we noticed that adult black grouse were alerted by raven calls during periods outside the breeding season. Since black grouse are large, extremely precocial birds, this reaction can hardly be explained by sensitization specifically to the threat of nest predation by ravens. This surprising observation prompted us to study the phenomenon more systematically. According to our knowledge, the response of birds to corvid vocalization has been studied in altricial birds only. We tested whether the black grouse distinguishes and responds specifically to playback calls of the common raven. Black grouse recognized raven calls and were alerted, displaying typical neck stretching, followed by head scanning, and eventual escape. Surprisingly, males tended to react faster and exhibited a longer duration of vigilance behavior compared to females. Although raven calls are recognized by adult black grouse out of the nesting period, they are not directly endangered by the raven. We speculate that the responsiveness of adult grouse to raven calls might be explained as a learned response in juveniles from nesting hens that is then preserved in adults, or by a known association between the raven and the red fox. In that case, calls of the raven would be rather interpreted as a warning signal of probable proximity of the red fox.

RevDate: 2019-04-08
CmpDate: 2019-04-08

Gutiérrez-López R, Martínez-de la Puente J, Gangoso L, et al (2019)

Effects of host sex, body mass and infection by avian Plasmodium on the biting rate of two mosquito species with different feeding preferences.

Parasites & vectors, 12(1):87 pii:10.1186/s13071-019-3342-x.

BACKGROUND: The transmission of mosquito-borne pathogens is strongly influenced by the contact rates between mosquitoes and susceptible hosts. The biting rates of mosquitoes depend on different factors including the mosquito species and host-related traits (i.e. odour, heat and behaviour). However, host characteristics potentially affecting intraspecific differences in the biting rate of mosquitoes are poorly known. Here, we assessed the impact of three host-related traits on the biting rate of two mosquito species with different feeding preferences: the ornithophilic Culex pipiens and the mammophilic Ochlerotatus (Aedes) caspius. Seventy-two jackdaws Corvus monedula and 101 house sparrows Passer domesticus were individually exposed to mosquito bites to test the effect of host sex, body mass and infection status by the avian malaria parasite Plasmodium on biting rates.

RESULTS: Ochlerotatus caspius showed significantly higher biting rates than Cx. pipiens on jackdaws, but non-significant differences were found on house sparrows. In addition, more Oc. caspius fed on female than on male jackdaws, while no differences were found for Cx. pipiens. The biting rate of mosquitoes on house sparrows increased through the year. The bird infection status and body mass of both avian hosts were not related to the biting rate of both mosquito species.

CONCLUSIONS: Host sex was the only host-related trait potentially affecting the biting rate of mosquitoes, although its effect may differ between mosquito and host species.

RevDate: 2019-03-29

Shimmura T, Tamura M, Ohashi S, et al (2019)

Cholecystokinin induces crowing in chickens.

Scientific reports, 9(1):3978 pii:10.1038/s41598-019-40746-9.

Animals that communicate using sound are found throughout the animal kingdom. Interestingly, in contrast to human vocal learning, most animals can produce species-specific patterns of vocalization without learning them from their parents. This phenomenon is called innate vocalization. The underlying molecular basis of both vocal learning in humans and innate vocalization in animals remains unknown. The crowing of a rooster is also innately controlled, and the upstream center is thought to be localized in the nucleus intercollicularis (ICo) of the midbrain. Here, we show that the cholecystokinin B receptor (CCKBR) is a regulatory gene involved in inducing crowing in roosters. Crowing is known to be a testosterone (T)-dependent behavior, and it follows that roosters crow but not hens. Similarly, T-administration induces chicks to crow. By using RNA-sequencing to compare gene expression in the ICo between the two comparison groups that either crow or do not crow, we found that CCKBR expression was upregulated in T-containing groups. The expression of CCKBR and its ligand, cholecystokinin (CCK), a neurotransmitter, was observed in the ICo. We also showed that crowing was induced by intracerebroventricular administration of an agonist specific for CCKBR. Our findings therefore suggest that the CCK system induces innate vocalization in roosters.

RevDate: 2019-02-27

McCune KB, Jablonski P, Lee SI, et al (2019)

Captive jays exhibit reduced problem-solving performance compared to wild conspecifics.

Royal Society open science, 6(1):181311 pii:rsos181311.

Animal cognitive abilities are frequently quantified in strictly controlled settings, with laboratory-reared subjects. Results from these studies have merit for clarifying proximate mechanisms of performance and the potential upper limits of certain cognitive abilities. Researchers often assume that performance on laboratory-based assessments accurately represents the abilities of wild conspecifics, but this is infrequently tested. In this experiment, we quantified the performance of wild and captive corvid subjects on an extractive foraging task. We found that performance was not equivalent, and wild subjects were faster at problem-solving to extract the food reward. By contrast, there was no difference in the time it took for captive and wild solvers to repeat the behaviour to get additional food rewards (learning speed). Our findings differ from the few other studies that have statistically compared wild and captive performance on assessments of problem-solving and learning. This indicates that without explicitly testing it, we cannot assume that captive animal performance on experimental tasks can be generalized to the species as a whole. To better understand the causes and consequences of a variety of animal cognitive abilities, we should measure performance in the social and physical environment in which the ability in question evolved.

RevDate: 2019-03-11
CmpDate: 2019-03-11

Bauch C, Boonekamp JJ, Korsten P, et al (2019)

Epigenetic inheritance of telomere length in wild birds.

PLoS genetics, 15(2):e1007827 pii:PGENETICS-D-18-01652.

Telomere length (TL) predicts health and survival across taxa. Variation in TL between individuals is thought to be largely of genetic origin, but telomere inheritance is unusual, because zygotes already express a TL phenotype, the TL of the parental gametes. Offspring TL changes with paternal age in many species including humans, presumably through age-related TL changes in sperm, suggesting an epigenetic inheritance mechanism. However, present evidence is based on cross-sectional analyses, and age at reproduction is confounded with between-father variation in TL. Furthermore, the quantitative importance of epigenetic TL inheritance is unknown. Using longitudinal data of free-living jackdaws Corvus monedula, we show that erythrocyte TL of subsequent offspring decreases with parental age within individual fathers, but not mothers. By cross-fostering eggs, we confirmed the paternal age effect to be independent of paternal age dependent care. Epigenetic inheritance accounted for a minimum of 34% of the variance in offspring TL that was explained by paternal TL. This is a minimum estimate, because it ignores the epigenetic component in paternal TL variation and sperm TL heterogeneity within ejaculates. Our results indicate an important epigenetic component in the heritability of TL with potential consequences for offspring fitness prospects.

RevDate: 2019-01-30

Umbers KDL, White TE, De Bona S, et al (2019)

The protective value of a defensive display varies with the experience of wild predators.

Scientific reports, 9(1):463 pii:10.1038/s41598-018-36995-9.

Predation has driven the evolution of diverse adaptations for defence among prey, and one striking example is the deimatic display. While such displays can resemble, or indeed co-occur with, aposematic 'warning' signals, theory suggests deimatic displays may function independently of predator learning. The survival value of deimatic displays against wild predators has not been tested before. Here we used the mountain katydid Acripeza reticulata to test the efficacy of a putative deimatic display in the wild. Mountain katydids have a complex defence strategy; they are camouflaged at rest, but reveal a striking red-, blue-, and black-banded abdomen when attacked. We presented live katydids to sympatric (experienced) and allopatric (naive) natural predators, the Australian magpie Cracticus tibicen, and observed bird reactions and katydid behaviors and survival during repeated interactions. The efficacy of the katydids' defence differed with predator experience. Their survival was greatest when faced with naïve predators, which provided clear evidence of the protective value of the display. In contrast, katydid survival was consistently less likely when facing experienced predators. Our results suggest that sympatric predators have learned to attack and consume mountain katydids despite their complex defense, and that their post-attack display can be an effective deterrent, particularly against naïve predators. These results suggest that deimatism does not require predator learning to afford protection, but that a predator can learn to expect the display and subsequently avoid it or ignore it. That sympatric predators learn to ignore the defense is a possible explanation for the mountain katydid's counter-intuitive behavior of revealing warning colors only after tactile stimuli from predator attack.

RevDate: 2019-08-19
CmpDate: 2019-08-19

Kleider-Offutt HM (2019)

Afraid of one afraid of all: When threat associations spread across face-types.

The Journal of general psychology, 146(1):93-110.

Fear can be acquired for objects not inherently associated with threat (e.g. birds), and this threat may generalize from prototypical to peripheral category members (e.g. crows vs. penguins). When categorizing people, pervasive stereotypes link Black men to assumed violence and criminality. Faces with Afrocentric features (prototypical) are more often associated with threat and criminality than non-Afrocentric (peripheral) faces regardless of whether the individual is Black or White. In this study, using a priming paradigm, threat associations related to negative racial stereotypes were tested as a vehicle for spreading fear across face-type categories. Results showed more negative than positive judgments for White face targets but only when the prime was primarily non-Afrocentric (i.e. Eurocentric). Black face targets were judged more negatively than positively regardless of prime. This suggests some cognitive processes related to threat generalizations of objects extend to complex social categories.

RevDate: 2019-06-05
CmpDate: 2019-06-05

Rubi TL, Clark DL, Keller JS, et al (2019)

Courtship behavior and coloration influence conspicuousness of wolf spiders (Schizocosa ocreata (Hentz)) to avian predators.

Behavioural processes, 162:215-220.

Signalers must balance the benefits of detection by intended receivers with the costs of detection by eavesdroppers. This trade-off is exemplified by sexual signaling systems, in which signalers experience sexual selection for conspicuousness to mates as well as natural selection for crypsis to predators. In this study, we examined how courtship behavior and body coloration influenced the conspicuousness of males to avian predators in the well-studied brush-legged wolf spider system (Schizocosa ocreata (Hentz)). We focused on three behaviors (courtship, walking, and freezing) and two coloration schemes (natural coloration and idealized background-matching coloration). We presented captive blue jays (Cyanocitta cristata) with video playbacks of male spiders in a presence-absence detection task and characterized conspicuousness by measuring response latency and detectability. We found that any type of motion significantly increased detectability, and that body coloration and behavior interacted to determine detectability while the spiders were in motion. Among spiders in motion, courting spiders were detected faster than walking spiders. Stationary (frozen) spiders, in contrast, were rarely detected. These results illustrate that male S. ocreata can be both highly conspicuous and highly cryptic to avian predators. Thus, while we find that courtship is conspicuous to avian predators in this system, we suggest that behavioral plasticity may mitigate some of the predation costs of the sexual signal.

RevDate: 2018-12-21

Lind J (2018)

What can associative learning do for planning?.

Royal Society open science, 5(11):180778 pii:rsos180778.

There is a new associative learning paradox. The power of associative learning for producing flexible behaviour in non-human animals is downplayed or ignored by researchers in animal cognition, whereas artificial intelligence research shows that associative learning models can beat humans in chess. One phenomenon in which associative learning often is ruled out as an explanation for animal behaviour is flexible planning. However, planning studies have been criticized and questions have been raised regarding both methodological validity and interpretations of results. Due to the power of associative learning and the uncertainty of what causes planning behaviour in non-human animals, I explored what associative learning can do for planning. A previously published sequence learning model which combines Pavlovian and instrumental conditioning was used to simulate two planning studies, namely Mulcahy & Call 2006 'Apes save tools for future use.' Science312, 1038-1040 and Kabadayi & Osvath 2017 'Ravens parallel great apes in flexible planning for tool-use and bartering.' Science357, 202-204. Simulations show that behaviour matching current definitions of flexible planning can emerge through associative learning. Through conditioned reinforcement, the learning model gives rise to planning behaviour by learning that a behaviour towards a current stimulus will produce high value food at a later stage; it can make decisions about future states not within current sensory scope. The simulations tracked key patterns both between and within studies. It is concluded that one cannot rule out that these studies of flexible planning in apes and corvids can be completely accounted for by associative learning. Future empirical studies of flexible planning in non-human animals can benefit from theoretical developments within artificial intelligence and animal learning.

RevDate: 2018-12-11

Ashton BJ, Ridley AR, A Thornton (2018)

Smarter through group living: A response to Smulders.

Learning & behavior pii:10.3758/s13420-018-0366-6 [Epub ahead of print].

We recently identified a strong, positive relationship between group size and individual cognitive performance, and a strong, positive relationship between female cognitive performance and reproductive success (Ashton, Ridley, Edwards, & Thornton in Nature, 554, 364-367, 2018). An opinion piece by Smulders (Learning & Behavior, https://doi.org/10.3758/s13420-018-0335-0 , 2018) raised the interesting notion that these patterns may be underlined by motivational factors. In this commentary, we highlight why none of the available data are consistent with this explanation, but instead support the argument that the demands of group living influence cognitive development, with knock-on consequences for fitness.

RevDate: 2018-12-17

Klump BC, Masuda BM, St Clair JJH, et al (2018)

Preliminary observations of tool-processing behaviour in Hawaiian crows Corvus hawaiiensis.

Communicative & integrative biology, 11(4):e1509637.

Very few animal species habitually make and use foraging tools. We recently discovered that the Hawaiian crow is a highly skilled, natural tool user. Most captive adults in our experiment spontaneously used sticks to access out-of-reach food from a range of extraction tasks, exhibiting a surprising degree of dexterity. Moreover, many birds modified tools before or during deployment, and some even manufactured tools from raw materials. In this invited addendum article, we describe and discuss these observations in more detail. Our preliminary data, and comparisons with the better-studied New Caledonian crow, suggest that the Hawaiian crow has extensive tool-modification and manufacture abilities. To chart the full extent of the species' natural tool-making repertoire, we have started conducting dedicated experiments where subjects are given access to suitable raw materials for tool manufacture, but not ready-to-use tools.

RevDate: 2019-02-21
CmpDate: 2019-02-21

Kelly DM, Bisbing TA, JF Magnotti (2019)

Use of medial axis for reorientation by the Clark's nutcracker (Nucifraga columbiana).

Behavioural processes, 158:192-199.

Many animals are challenged with the task of reorientation. Considerable research over the years has shown a diversity of species extract geometric information (e.g., distance and direction) from continuous surfaces or boundaries to reorient. How this information is extracted from the environment is less understood. Three encoding strategies that have received the most study are the use of principal axes, medial axis or local geometric cues. We used a modeling approach to investigate which of these three general strategies best fit the spatial search data of a highly-spatial corvid, the Clark's nutcracker (Nucifraga columbiana). Individual nutcrackers were trained in a rectangular-shaped arena, and once accurately locating a hidden goal, received non-reinforced tests in an L-shaped arena. The specific shape of this arena allowed us to dissociate among the three general encoding strategies. Furthermore, we reanalyzed existing data from chicks, pigeons and humans using our modeling approach. Overall, we found the most support for the use of the medial axis, although we additionally found that pigeons and humans may have engaged in random guessing. As with our previous studies, we find no support for the use of principal axes.

RevDate: 2019-09-04
CmpDate: 2019-09-04

Cunningham CX, Johnson CN, Barmuta LA, et al (2018)

Top carnivore decline has cascading effects on scavengers and carrion persistence.

Proceedings. Biological sciences, 285(1892):.

Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania's top carnivore, the Tasmanian devil (Sarcophilus harrisii), has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native mesopredators was best predicted by competition for carrion, whereas consumption by the invasive mesopredator, the feral cat (Felis catus), was better predicted by the landscape-level abundance of devils, suggesting a relaxed landscape of fear where devils are suppressed. Reduced discovery of carcasses by devils was balanced by the increased discovery by mesopredators. Nonetheless, carcasses persisted approximately 2.6-fold longer where devils have declined, highlighting their importance for rapid carrion removal. The major beneficiary of increased carrion availability was the forest raven (Corvus tasmanicus). Population trends of ravens increased 2.2-fold from 1998 to 2017, the period of devil decline, but this increase occurred Tasmania-wide, making the cause unclear. This case study provides a little-studied potential mechanism for mesopredator release, with broad relevance to the vast areas of the world that have suffered carnivore declines.

RevDate: 2019-08-07
CmpDate: 2019-08-07

Kent SJW, R Morrison (2018)

Rural and urban differences in orthognathic surgical patients in the north east of Scotland.

The British journal of oral & maxillofacial surgery, 56(10):931-935.

We have previously identified differences in the presentation and treatment of cancer between patients who live in rural compared with urban areas, but have not yet seen differences in those treated by orthognathic surgery. We hypothesised that patients from areas further away from the hospital face higher costs to attend and may not present with minor problems as often as those who live nearby. We therefore retrospectively reviewed all those (n=216) who had presented for orthognathic surgery over a six-year period (May 2011 to May 2017). The severity of malocclusion and facial asymmetry was established by combining measurements of intraoperative movements. Rurality was measured as the distance from home to the hospital at the time of operation. Those with smaller intraoperative movements (less than 7mm combined movement) lived significantly closer to the hospital as the crow flies (mean difference 15.13 miles, 95% CI 0.20 to 30.48, p=0.05) and could travel there more quickly (mean difference 65minutes 95% CI 9.8 to 121.7, p=0.02) than those with larger movements. Our results suggest that patients with small malocclusions and slight facial asymmetry who live further away from the hospital, may be less likely to present for operation than those who live closer. We explain why socioeconomic class is unlikely to confound our results, and suggest potential ways to minimise the effect observed.

RevDate: 2018-11-20

Amici F (2018)

An Evolutionary Approach to the Study of Collaborative Remembering?.

Topics in cognitive science [Epub ahead of print].

Hope and Gabbert (2008) and Jay and colleagues (in press) show us that collaborative remembering, in certain contexts, may result in incomplete and less accurate memories. Here, I will discuss the evolutionary origins of this behavior, linking it to phenomena such as social contagion, conformity, and social learning, which are highly adaptive and widespread across non-human taxa.

RevDate: 2018-12-20

Ling H, Mclvor GE, Nagy G, et al (2018)

Simultaneous measurements of three-dimensional trajectories and wingbeat frequencies of birds in the field.

Journal of the Royal Society, Interface, 15(147):.

Tracking the movements of birds in three dimensions is integral to a wide range of problems in animal ecology, behaviour and cognition. Multi-camera stereo-imaging has been used to track the three-dimensional (3D) motion of birds in dense flocks, but precise localization of birds remains a challenge due to imaging resolution in the depth direction and optical occlusion. This paper introduces a portable stereo-imaging system with improved accuracy and a simple stereo-matching algorithm that can resolve optical occlusion. This system allows us to decouple body and wing motion, and thus measure not only velocities and accelerations but also wingbeat frequencies along the 3D trajectories of birds. We demonstrate these new methods by analysing six flocking events consisting of 50 to 360 jackdaws (Corvus monedula) and rooks (Corvus frugilegus) as well as 32 jackdaws and 6 rooks flying in isolated pairs or alone. Our method allows us to (i) measure flight speed and wingbeat frequency in different flying modes; (ii) characterize the U-shaped flight performance curve of birds in the wild, showing that wingbeat frequency reaches its minimum at moderate flight speeds; (iii) examine group effects on individual flight performance, showing that birds have a higher wingbeat frequency when flying in a group than when flying alone and when flying in dense regions than when flying in sparse regions; and (iv) provide a potential avenue for automated discrimination of bird species. We argue that the experimental method developed in this paper opens new opportunities for understanding flight kinematics and collective behaviour in natural environments.

RevDate: 2018-12-17
CmpDate: 2018-12-17

Passanha V, AD Brescovit (2018)

On the Neotropical spider Subfamily Masteriinae (Araneae, Dipluridae).

Zootaxa, 4463(1):1-73 pii:zootaxa.4463.1.1.

The Neotropical species of the diplurid subfamily Masteriinae are revised and redefined. Masteriinae now comprises four genera, Masteria L. Koch, 1893, Striamea Raven, 1981, a new genus, Siremata n. gen. and Edwa Raven, 2015, a fossil genus. The type species, Masteria hirsuta L. Koch, 1893, was used as basis for comparison and the knowledge of the genus has increased. Twelve species of Masteria are redescribed and eight new species are described: M. amarumayu n. sp. and M. mutum n. sp., from Brazil; M. yacambu n. sp., from Venezuela; M. sabrinae n. sp., from Martinique; M. tayrona n. sp., from Colombia; M. aguaruna n. sp., from Peru, M. soucouyant n. sp., from Trinidad and Tobago; and M. galipote n. sp., from the Dominican Republic. Females of Masteria aimeae (Alayón, 1995) and M. golovatchi Alayón, 1995 are described for the first time. Females of M. spinosa (Petrunkevitch, 1925), M. petrunkevitchi (Chickering, 1964), M. lewisi (Chickering, 1964), M. barona (Chickering, 1966), M. downeyi (Chickering, 1966), M. simla (Chickering, 1966), M. colombiensis Raven, 1981 and M. pecki Gertsch, 1982 are illustrated for the first time and rediagnosed. Masteria tovarensis (Simon, 1889) and M. cyclops (Simon, 1889) are synonymized with M. lucifuga (Simon, 1889). Masteria modesta (Simon, 1892) is considered as species inquirendae and M. emboaba Pedroso, Baptista Bertani, 2015 is considered as incertae sedis, as the type is lost. Both species of Striamea are revised and redescribed. A new genus, Siremata n. gen., is described and includes three Amazonian species: S. valteri n. sp., S. juruti n. sp., S. lucasae n. sp. Knowledge of the distribution ranges of the Neotropical Masteriinae are increased.

RevDate: 2018-12-21
CmpDate: 2018-12-21

Almeida MQ, Salvatierra L, JW De Morais (2018)

A new species of Masteria L. Koch, 1873 (Dipluridae: Masteriinae) from Guyana.

Zootaxa, 4434(2):366-368 pii:zootaxa.4434.2.6.

Mygalomorphs are a diverse spider group with primitive characteristics composed of the largest spider species in the world, however some species may be very small (Bond et al. 2012; Rogerio et al. 2013). The small spiders of the subfamily Masteriinae (Dipluridae, Mygalomorphae) can be found in Asia and South America (Raven 1981; Pedroso et al. 2015; WSC 2017). The subfamily is represented by two genera: Masteria L. Koch, 1873 and Striamea Raven, 1981. Masteria species can be identified by the following combination of characters: absence of cuspules in endites and labium; zero, two, six or eight eyes; and with or without paraembolic apophysis on the male palpal bulb (Raven 1981, 1985, 1991; Alayón 1995; Bertani et al. 2013; Pedroso et al. 2015). Currently, 24 species of Masteria are described, with 6 species found in South America: Masteria colombiensis, Raven, 1981 from Colombia; M. manauara Bertani, Cruz Oliveira 2013 and M. emboaba Pedroso, Baptista Bertani, 2015 from Brazil; M. cyclops (Simon 1889), M. tovarensis (Simon, 1889) and M. lucifuga (Simon, 1889) from Venezuela (WSC 2017). We document herein the first record and description of a new species of the genus Masteria from Guyana.

RevDate: 2019-03-11
CmpDate: 2019-03-11

Hausberger M, Boigné A, Lesimple C, et al (2018)

Wide-eyed glare scares raptors: From laboratory evidence to applied management.

PloS one, 13(10):e0204802.

Raptors are one of the most important causes of fatalities due to their collisions with aircrafts as well as being the main victims of collisions with constructions. They are difficult to deter because they are not influenced by other airspace users or ground predators. Because vision is the primary sensory mode of many diurnal raptors, we evaluated the reactions of captive raptors to a "superstimulus" (a "paradoxical effect whereby animals show greater responsiveness to an exaggerated stimulus than to the natural stimulus") that combined an "eye shape" stimulus (as many species have an aversion for this type of stimulus) and a looming movement (LE). This looming stimulus mimics an impending collision and induces avoidance in a wide range of species. In captivity, raptors showed a clear aversion for this LE stimulus. We then tested it in a real life setting: at an airport where raptors are abundant. This study is the first to show the efficiency of a visual non-invasive repellent system developed on the basis of both captive and field studies. This system deterred birds of prey and corvids through aversion, and did not induce habituation. These findings suggest applications for human security as well as bird conservation, and further research on avian visual perception and sensitivity to signals.

RevDate: 2019-05-06
CmpDate: 2019-05-06

Mitchell PW (2018)

The fault in his seeds: Lost notes to the case of bias in Samuel George Morton's cranial race science.

PLoS biology, 16(10):e2007008.

The discovery of nearly 180-year-old cranial measurements in the archives of 19th century American physician and naturalist Samuel George Morton can address a lingering debate, begun in the late 20th century by paleontologist and historian of science Stephen Jay Gould, about the unconscious bias alleged in Morton's comparative data of brain size in human racial groups. Analysis of Morton's lost data and the records of his studies does not support Gould's arguments about Morton's biased data collection. However, historical contextualization of Morton with his scientific peers, especially German anatomist Friedrich Tiedemann, suggests that, while Morton's data may have been unbiased, his cranial race science was not. Tiedemann and Morton independently produced similar data about human brain size in different racial groups but analyzed and interpreted their nearly equivalent results in dramatically different ways: Tiedemann using them to argue for equality and the abolition of slavery, and Morton using them to entrench racial divisions and hierarchy. These differences draw attention to the epistemic limitations of data and the pervasive role of bias within the broader historical, social, and cultural context of science.

RevDate: 2019-03-21
CmpDate: 2019-03-21

Shin DA, Kim C, Yudoyono F, et al (2018)

Feasibility of Percutaneous Robot-Assisted Epiduroscopic System.

Pain physician, 21(5):E565-E571.

BACKGROUND: Endoscopy has replaced open surgery, especially in spinal surgery. Among them, image-guided epiduroscopy allows pain generators to be identified, including epidural adhesion, fibrotic tissues, root compression, and spinal stenosis. However, the heavy lead apron worn by pain physicians to avoid exposure to radiation can induce occupational hazards, such as orthopedic complications and radiation-induced cancer. Hence, we developed a robotic system to address these problems.

OBJECTIVE: The aim of the study was to evaluate the feasibility of a robot-controlled epiduroscopic system.

STUDY DESIGN: In vivo animal experiment.

SETTING: University in Republic of Korea.

METHODS: The robot-controlled epiduroscopic system was developed using the open architecture robot system (The Raven Surgical Robotic System, CITRIS, Berkley, CA, USA). The robotic system consists of a lab-made epiduroscope, steering section, robotic arm, and manipulator. For the in vivo study, 2 Yorkshire pigs were used to simulate an epiduroscopic procedure with the robotic system.

RESULTS: The insertion and steering of the catheter was performed safely, and epiduroscopic visualization was obtained without side effects. There were no device-related complications. Radiation exposure for the primary operator was 80% lower than the levels found during conventional epiduroscopic procedures. All live pigs showed normal behavior without any signs of pain. The mean time to reach the target region was less than 8 minutes.

LIMITATIONS: The epiduroscopic procedure was performed on pigs and not on humans. The dimensions of the spinal canal of pigs cannot compare to those of humans.

CONCLUSIONS: We demonstrated the feasibility of the robot-assisted epiduroscopic system.

KEY WORDS: Epiduroscopy, robotic system, spine, pig, animal model.

RevDate: 2019-01-02
CmpDate: 2019-01-02

Elderbrock EK, Small TW, SJ Schoech (2018)

Adult Provisioning Influences Nestling Corticosterone Levels in Florida Scrub Jays (Aphelocoma coerulescens).

Physiological and biochemical zoology : PBZ, 91(6):1083-1090.

We studied Florida scrub jay (Aphelocoma coerulescens) nestlings to examine the relationship between parental feeding rates and levels of corticosterone (CORT), a metabolic and stress-related steroid hormone hypothesized to play a role in mediating begging behavior. It has been documented that nutritional deficiency results in increased glucocorticoid levels in nestling birds. Further, previous studies have found that CORT levels of Florida scrub jay nestlings are negatively correlated with parental nest attendance and provisioning rates; however, the behavioral observations were made several days before the collection of samples to assess CORT levels. Few studies have investigated whether experience immediately before sampling impacts nestling glucocorticoid levels, especially in a free-living species. By monitoring parental activity at the nest before sample collection, we found that nestling CORT levels varied as a function of parental provisioning rate and the time since their last feed. However, counter to our predictions, higher provisioning rates and more recent feedings were associated with higher CORT levels in nestlings rather than lower CORT levels. These results suggest that some aspect of parental provisioning results in increased CORT levels in nestling Florida scrub jays.

RevDate: 2018-12-11
CmpDate: 2018-12-11

Ganz K, Jenni L, Madry MM, et al (2018)

Acute and Chronic Lead Exposure in Four Avian Scavenger Species in Switzerland.

Archives of environmental contamination and toxicology, 75(4):566-575.

Despite irrefutable evidence of its negative impact on animal behaviour and physiology, lethal and sublethal lead poisoning of wildlife is still persistent and widespread. For scavenging birds, ingestion of ammunition, or fragments thereof, is the major exposure route. In this study, we examined the occurrence of lead in four avian scavengers of Switzerland and how it differs between species, regions, and age of the bird. We measured lead concentration in liver and bone of the two main alpine avian scavengers (golden eagle Aquila chrysaetos and bearded vulture Gypaetus barbatus) over the entire area of the Swiss Alps and two of the main avian scavengers occurring in the lowlands of Switzerland (red kite Milvus milvus and common raven Corvus corax). Of those four species, only the bearded vulture is an obligate scavenger. We found that lead burdens in the two alpine avian scavengers were higher than those found for the same species elsewhere in Europe or North America and reached levels compatible with acute poisoning, whereas lead burdens of the two lowland avian scavengers seemed to be lower. Several golden eagles, but only one red kite with abnormally high bone lead concentrations were found. In all four species, a substantial proportion of birds had elevated levels which presumably represent recent (liver lead levels) or past (bone lead levels) uptake of sublethal doses of lead.

RevDate: 2019-06-09

Townsend AK, Taff CC, Jones ML, et al (2019)

Apparent inbreeding preference despite inbreeding depression in the American crow.

Molecular ecology, 28(5):1116-1126.

Although matings between relatives can have negative effects on offspring fitness, apparent inbreeding preference has been reported in a growing number of systems, including those with documented inbreeding depression. Here, we examined evidence for inbreeding depression and inbreeding preference in two populations (Clinton, New York, and Davis, California, USA) of the cooperatively breeding American crow (Corvus brachyrhynchos). We then compared observed inbreeding strategies with theoretical expectations for optimal, adaptive levels of inbreeding, given the inclusive fitness benefits and population-specific magnitude of inbreeding depression. We found that low heterozygosity at a panel of 33 microsatellite markers was associated with low survival probability (fledging success) and low white blood cell counts among offspring in both populations. Despite these costs, our data were more consistent with inbreeding preference than avoidance: The observed heterozygosity among 396 sampled crow offspring was significantly lower than expected if local adults were mating by random chance. This pattern was consistent across a range of spatial scales in both populations. Adaptive levels of inbreeding, given the magnitude of inbreeding depression, were predicted to be very low in the California population, whereas complete disassortative mating was predicted in the New York population. Sexual conflict might have contributed to the apparent absence of inbreeding avoidance in crows. These data add to an increasing number of examples of an "inbreeding paradox," where inbreeding appears to be preferred despite inbreeding depression.

RevDate: 2019-04-01

Simonds VW, Kim FL, LaVeaux D, et al (2019)

Guardians of the Living Water: Using a Health Literacy Framework to Evaluate a Child as Change Agent Intervention.

Health education & behavior : the official publication of the Society for Public Health Education, 46(2):349-359.

BACKGROUND: American Indian communities in the United States experience considerable health inequities, including increased exposure to environmental contaminants. Consequently, community members of the Apsáalooke (Crow) Nation identified the lack of water-related environmental knowledge among children as an area of concern.

AIM: The purpose of this study was to provide a feasibility evaluation of an increasingly sophisticated environmental health literacy program for children.

METHOD: A community-academic partnership developed and piloted the Guardians of the Living Water program to increase environmental health literacy among children and their families on the Crow reservation. Nutbeam's framework for health literacy, a schema based on functional, interactive, and critical literacy, shaped the program evaluation. We used a within-subjects, quasi-experimental design without a control group. Interviews with children and parents were used to assess the feasibility of the program, while pre-/posttests assessed changes in knowledge, skills, and behavior.

RESULTS: Compared with preintervention responses, those from postintervention indicated significant increases for selected knowledge and attitude components. Based on qualitative interviews with children and caregivers, the camp was a valuable experience and increased knowledge of water quality science and reinforced cultural knowledge.

DISCUSSION: This success of our program stems from the trust initially built between partners and then expanded throughout the community. The program and the evaluation benefited from both the health literacy framework and from our integration of Apsáalooke values.

CONCLUSION: Our findings suggest that a community-based intervention designed to increase environmental health literacy among youth and their social networks is feasible and acceptable to this American Indian community.

RevDate: 2019-08-20

Wheatcroft D, TD Price (2018)

Collective Action Promoted by Key Individuals.

The American naturalist, 192(4):401-414.

Explaining why individuals participate in risky group behaviors has been a long-term challenge. We experimentally studied the formation of groups of birds (mobs) that aggressively confront predators and avian nest parasites and developed a theoretical model to evaluate the conditions under which mobs arise. We presented taxidermied mounts of predators on adult birds (hawks and owls) and of nest threats (crows and cuckoos) at different distances to nests of Phylloscopus warblers. Even when alone, birds are aggressive toward predators of adult birds, both at and away from their nests. By contrast, birds aggressively confront nest threats alone only when they have a nest nearby. However, strong initial responses by nest owners lead individuals without nearby nests to increase their responses, thereby generating a mob. Building on these findings, we derive the conditions in which individuals are incentivized to invest more when joining a high-gain individual compared to when acting alone. Strong responses of high-gain individuals acting alone tend to reduce the investments of other high-gain individuals that subsequently join. However, individuals that benefit sufficiently little from acting alone increase their investments when joining a high-gain individual and can even be sufficiently incentivized to join in when they would otherwise not act alone. Together, these results suggest an important role for key individuals in the generation of some group behaviors.

RevDate: 2018-11-14
CmpDate: 2018-11-01

Hennefield L, Hwang HG, Weston SJ, et al (2018)

Meta-analytic techniques reveal that corvid causal reasoning in the Aesop's Fable paradigm is driven by trial-and-error learning.

Animal cognition, 21(6):735-748.

The classic Aesop's fable, Crow and the Pitcher, has inspired a major line of research in comparative cognition. Over the past several years, five articles (over 32 experiments) have examined the ability of corvids (e.g., rooks, crows, and jays) to complete lab-based analogs of this fable, by requiring them to drop stones and other objects into tubes of water to retrieve a floating worm (Bird and Emery in Curr Biol 19:1-5, 2009b; Cheke et al. in Anim Cogn 14:441-455, 2011; Jelbert et al. in PLoS One 3:e92895, 2014; Logan et al. in PLoS One 7:e103049, 2014; Taylor et al. in Gray R D 12:e26887, 2011). These researchers have stressed the unique potential of this paradigm for understanding causal reasoning in corvids. Ghirlanda and Lind (Anim Behav 123:239-247, 2017) re-evaluated trial-level data from these studies and concluded that initial preferences for functional objects, combined with trial-and-error learning, may account for subjects' performance on key variants of the paradigm. In the present paper, we use meta-analytic techniques to provide more precise information about the rate and mode of learning that occurs within and across tasks. Within tasks, subjects learned from successful (but not unsuccessful) actions, indicating that higher-order reasoning about phenomena such as mass, volume, and displacement is unlikely to be involved. Furthermore, subjects did not transfer information learned in one task to subsequent tasks, suggesting that corvids do not engage with these tasks as variants of the same problem (i.e., how to generate water displacement to retrieve a floating worm). Our methodological analysis and empirical findings raise the question: Can Aesop's fable studies distinguish between trial-and-error learning and/or higher-order causal reasoning? We conclude they cannot.

RevDate: 2018-11-14

Mason LD, Wardell-Johnson G, Luxton SJ, et al (2018)

Predators Show Seasonal Predilections for Model Clay Spiders in an Urban Environment.

Scientific reports, 8(1):12444.

Predator-prey interactions may be altered under human-induced rapid environmental change, such as urbanisation. Extensive clearing in urban areas may leave short-range endemic species, such as mygalomorph spiders, more vulnerable to local extinction through predation in remaining remnants. Predation rates on Australian mygalomorph spiders were assessed using clay models of two size classes (5 cm, 3 cm), during two time periods in 2016 (January-February, July-August). Size and phenology of models resembled the mygalomorph genera Aname and Teyl occurring in these local urban remnants. Local predator guilds were significantly influenced by leaf-litter cover (%) and proportion of surrounding parkland. Preference for spider vs. control models was consistent across all predator types (bird, rodent, lizard and wasp), but specialist spider wasps (Pompilidae) only attacked spider models. Generalist predators (birds, lizards and rodents) were more opportunistic. Lizards and rodents exhibit similar predation behaviour, indicating there may be some inter-specific competition. Invasive generalists (e. g. rodents) or urban adapters (e. g. corvids) are more likely to represent an increased threat to spiders than are co-evolved specialists (e.g. spider wasps).

RevDate: 2019-08-26
CmpDate: 2019-08-26

Steyaert SMJG, Frank SC, Puliti S, et al (2018)

Special delivery: scavengers direct seed dispersal towards ungulate carcasses.

Biology letters, 14(8):.

Cadaver decomposition islands around animal carcasses can facilitate establishment of various plant life. Facultative scavengers have great potential for endozoochory, and often aggregate around carcasses. Hence, they may disperse plant seeds that they ingest across the landscape towards cadaver decomposition islands. Here, we demonstrate this novel mechanism along a gradient of wild tundra reindeer carcasses. First, we show that the spatial distribution of scavenger faeces (birds and foxes) was concentrated around carcasses. Second, faeces of the predominant scavengers (corvids) commonly contained viable seeds of crowberry, a keystone species of the alpine tundra with predominantly vegetative reproduction. We suggest that cadaver decomposition islands function as endpoints for directed endozoochory by scavengers. Such a mechanism could be especially beneficial for species that rely on small-scale disturbances in soil and vegetation, such as several Nordic berry-producing species with cryptic generative reproduction.

RevDate: 2019-08-22
CmpDate: 2019-08-22

Campo JV, JA Bridge (2018)

Exploring the Impact of 13 Reasons Why: Looking for Light Amidst the Heat . . .

Journal of the American Academy of Child and Adolescent Psychiatry, 57(8):547-549.

A Letter to the Editor by Kieling and collegues1 in this month's Journal attempts to explore the impact of the Netflix series 13 Reasons Why (13RW) on the thinking and behavior of adolescent viewers. The series is an adaptation of a 2007 novel by Jay Asher, and tells the story of an adolescent girl who dies by suicide following a series of traumas and disappointments that she catalogues before her death on 13 audiotapes. The tapes are left behind with the expectation that each of the individuals presumably responsible for her suicide will listen and better understand their individual and collective failures. Since its release and airing in 2017, the show has generated considerable heated debate and controversy, largely due to concerns about its potential for suicide contagion.

RevDate: 2018-11-14

Sutton JT, Helmkampf M, Steiner CC, et al (2018)

A High-Quality, Long-Read De Novo Genome Assembly to Aid Conservation of Hawaii's Last Remaining Crow Species.

Genes, 9(8):.

Abstract: Genome-level data can provide researchers with unprecedented precision to examine the causes and genetic consequences of population declines, which can inform conservation management. Here, we present a high-quality, long-read, de novo genome assembly for one of the world's most endangered bird species, the 'Alalā (Corvus hawaiiensis; Hawaiian crow). As the only remaining native crow species in Hawai'i, the 'Alalā survived solely in a captive-breeding program from 2002 until 2016, at which point a long-term reintroduction program was initiated. The high-quality genome assembly was generated to lay the foundation for both comparative genomics studies and the development of population-level genomic tools that will aid conservation and recovery efforts. We illustrate how the quality of this assembly places it amongst the very best avian genomes assembled to date, comparable to intensively studied model systems. We describe the genome architecture in terms of repetitive elements and runs of homozygosity, and we show that compared with more outbred species, the 'Alalā genome is substantially more homozygous. We also provide annotations for a subset of immunity genes that are likely to be important in conservation management, and we discuss how this genome is currently being used as a roadmap for downstream conservation applications.

RevDate: 2019-09-05
CmpDate: 2019-07-30

Gonçalves A, D Biro (2018)

Comparative thanatology, an integrative approach: exploring sensory/cognitive aspects of death recognition in vertebrates and invertebrates.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 373(1754):.

Evolutionary thanatology benefits from broad taxonomic comparisons of non-human animals' responses to death. Furthermore, exploring the sensory and cognitive bases of these responses promises to allow classification of the underlying mechanisms on a spectrum from phylogenetically ancient to more derived traits. We draw on studies of perception and cognition in invertebrate and vertebrate taxa (with a focus on arthropods, corvids, proboscids, cetaceans and primates) to explore the cues that these animals use to detect life and death in others, and discuss proximate and ultimate drivers behind their capacities to do so. Parallels in thanatological behaviour exhibited by the last four taxa suggest similar sensory-cognitive processing rules for dealing with corpses, the evolution of which may have been driven by complex social environments. Uniting these responses is a phenomenon we term 'animacy detection malfunction', whereupon the corpse, having both animate and inanimate attributes, creates states of fear/curiosity manifested as approach/avoidance behaviours in observers. We suggest that integrating diverse lines of evidence (including the 'uncanny valley' effect originating from the field of robotics) provides a promising way to advance the field, and conclude by proposing avenues for future research.This article is part of the theme issue 'Evolutionary thanatology: impacts of the dead on the living in humans and other animals'.

RevDate: 2019-09-05
CmpDate: 2019-07-30

Swift K, JM Marzluff (2018)

Occurrence and variability of tactile interactions between wild American crows and dead conspecifics.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 373(1754):.

Observations of some mammals and birds touching their dead provoke questions about the motivation and adaptive value of this potentially risky behaviour. Here, we use controlled experiments to determine if tactile interactions are characteristic of wild American crow responses to dead crows, and what the prevalence and nature of tactile interactions suggests about their motivations. In Experiment 1, we test if food or information acquisition motivates contact by presenting crows with taxidermy-prepared dead crows, and two species crows are known to scavenge: dead pigeons and dead squirrels. In Experiment 2, we test if territoriality motivates tactile interactions by presenting crows with taxidermy crows prepared to look either dead or upright and life-like. In Experiment 1, we find that crows are significantly less likely to make contact but more likely to alarm call and recruit other birds in response to dead crows than to dead pigeons and squirrels. In addition, we find that aggressive and sexual encounters with dead crows are seasonally biased. These findings are inconsistent with feeding or information acquisition-based motivation. In Experiment 2, we find that crows rarely dive-bomb and more often alarm call and recruit other crows to dead than to life-like crows, behaviours inconsistent with responses given to live intruders. Consistent with a danger response hypothesis, our results show that alarm calling and neighbour recruitment occur more frequently in response to dead crows than other stimuli, and that touching dead crows is atypical. Occasional contacts, which take a variety of aggressive and sexual forms, may result from an inability to mediate conflicting stimuli.This article is part of the theme issue 'Evolutionary thanatology: impacts of the dead on the living in humans and other animals'.

RevDate: 2018-07-11

Smulders TV (2018)

Smarter through group living?.

Learning & behavior pii:10.3758/s13420-018-0335-0 [Epub ahead of print].

Wild Australian magpies living (or growing up) in larger social groups take fewer trials to solve a battery of four cognitive tests than those living (or growing up) in smaller groups. The tests all draw on a common underlying factor, but is this factor cognitive or motivational?

RevDate: 2018-11-19
CmpDate: 2018-11-19

Wójciak P, J Rybakowski (2018)

Clinical picture, pathogenesis and psychometric assessment of negative symptoms of schizophrenia.

Psychiatria polska, 52(2):185-197.

Negative symptoms of schizophrenia constitute a serious diagnostic and therapeutic problem. They substantially account for the impairment of health, social functioning and quality of life whereas treatment is difficult. In this paper the development of the concept of schizophrenia and negative symptoms is presented. The models of positive and negative symptoms, introduced in the 1980's by Timothy Crow and Nancy Andreasen, and William Carpenter's concept of so-called deficit syndrome with the criteria of the division of negative symptoms into the primary and secondary, are discussed. Current views on the pathogenesis of negative symptoms are shown with reference to neuroimaging studies, neurotransmitter alterations, neuropsychological deficits, genetic, immunological and epidemiological studies. A subsection is devoted to the diagnostics tools for negative symptoms. Chronologically, they are divided into scales of the 1st and 2nd generation. The first generation includes: the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), the Positive and Negative Syndrome Scale (PANSS), the Schedule for the Deficit Syndrome (SDS), and the Proxy for Deficit Syndrome. The second generation scales, developed as a result of the recommendation by American experts in 2006, include: the Brief Negative Syndrome Scale (BNSS) and the Clinical Assessment Interview for Negative Symptoms (CAINS), also the self-assessment scales: the Motivation and Pleasure Scale - Self Report (MAP-SR) and the Self-assessment of Negative Symptoms (SNS). The BNSS and the SNS scales, whose Polish versions were elaborated in the Department of Adult Psychiatry of Poznan University of Medical Sciences, are discussed in-depth.

RevDate: 2019-08-01

Hampton R (2019)

Parallel overinterpretation of behavior of apes and corvids.

Learning & behavior, 47(2):105-106.

The report by Kabadayi and Osvath (Science, 357(6347), 202-204, 2017) does not demonstrate planning in ravens. The behavior of corvids and apes is fascinating and will be best appreciated through well-designed experiments that explicitly test alternative explanations and that are interpreted without unjustified anthropomorphic embellishment.

RevDate: 2018-10-15
CmpDate: 2018-10-15

Komar N, Panella NA, Golnar AJ, et al (2018)

Forage Ratio Analysis of the Southern House Mosquito in College Station, Texas.

Vector borne and zoonotic diseases (Larchmont, N.Y.), 18(9):485-490.

Culex quinquefasciatus is the principal vector of West Nile virus (WNV) in the South Central United States, yet limited data on host utilization are available. We evaluated host utilization over a 3-month period in 2013 in a residential landscape in College Station, Texas. PCR sequencing of the mitochondrial cytochrome oxidase 1 gene permitted molecular identification of vertebrate bloodmeals to the species level. Forage ratio analysis identified bird species that were overutilized and underutilized by comparing community feeding index values to expected relative abundance values of bird species, derived from eBird data. Community feeding index values were also used in conjunction with reservoir competence data from the literature to generate reservoir capacity index values, a means of identifying relative importance of vertebrate reservoir hosts. Of 498 blood-engorged Cx. quinquefasciatus, 313 (62.9%) were identified to vertebrate species. The majority (95.5%) of bloodmeals originated from avian species with the remainder from mammals, but not humans. Northern mockingbird (Mimus polyglottos) was the principal host for mosquito feeding in June and July, but northern cardinal (Cardinalis cardinalis) became primary host in August. Forage ratio analysis revealed the overutilization of house finch (Haemorhous mexicanus), American robin (Turdus migratorius), northern mockingbird, northern cardinal, white-winged dove (Zenaida asiatica), and mourning dove (Zenaida macroura). Great-tailed grackle (Quiscalus mexicanus), blue jay (Cyanocitta cristata), and Carolina wren (Thryothorus ludovicianus) were under-utilized relative to availability. Reservoir capacity calculations suggested that northern mockingbird and northern cardinal were the principal amplifiers in the study area. These data identify the primary avian species contributing to the enzootic amplification of WNV in East-Central Texas and reveal that the heavy feeding on moderately competent hosts and no feeding on humans likely limit epidemics in this region.

RevDate: 2019-04-19
CmpDate: 2019-04-19

Szipl G, Ringler E, T Bugnyar (2018)

Attacked ravens flexibly adjust signalling behaviour according to audience composition.

Proceedings. Biological sciences, 285(1880):.

A fundamental attribute of social intelligence is the ability to monitor third-party relationships, which has been repeatedly demonstrated in primates, and recently also in captive ravens. It is yet unknown how ravens make use of this ability when dealing with different types of social relationships simultaneously during complex real-life situations. Free-ranging non-breeder ravens live in societies characterized by high fission-fusion dynamics and structured by age, pair-bond status and kinship. Here, we show that free-ranging ravens modify communication during conflicts according to audience composition. When being attacked by dominant conspecifics, victims of aggression signal their distress via defensive calls. Victims increased call rates when their kin were in the bystander audience, but reduced call rates when the bystanders were bonding partners of their aggressors. Hence, ravens use social knowledge flexibly and probably based on their own need (i.e. alert nearby allies and avoid alerting nearby rivals).

RevDate: 2019-03-25
CmpDate: 2019-03-25

Roos S, Smart J, Gibbons DW, et al (2018)

A review of predation as a limiting factor for bird populations in mesopredator-rich landscapes: a case study of the UK.

Biological reviews of the Cambridge Philosophical Society, 93(4):1915-1937.

The impact of increasing vertebrate predator numbers on bird populations is widely debated among the general public, game managers and conservationists across Europe. However, there are few systematic reviews of whether predation limits the population sizes of European bird species. Views on the impacts of predation are particularly polarised in the UK, probably because the UK has a globally exceptional culture of intensive, high-yield gamebird management where predator removal is the norm. In addition, most apex predators have been exterminated or much depleted in numbers, contributing to a widely held perception that the UK has high numbers of mesopredators. This has resulted in many high-quality studies of mesopredator impacts over several decades. Here we present results from a systematic review of predator trends and abundance, and assess whether predation limits the population sizes of 90 bird species in the UK. Our results confirm that the generalist predators Red Fox (Vulpes vulpes) and Crows (Corvus corone and C. cornix) occur at high densities in the UK compared with other European countries. In addition, some avian and mammalian predators have increased numerically in the UK during recent decades. Despite these high and increasing densities of predators, we found little evidence that predation limits populations of pigeons, woodpeckers and passerines, whereas evidence suggests that ground-nesting seabirds, waders and gamebirds can be limited by predation. Using life-history characteristics of prey species, we found that mainly long-lived species with high adult survival and late onset of breeding were limited by predation. Single-brooded species were also more likely to be limited by predation than multi-brooded species. Predators that depredate prey species during all life stages (i.e. from nest to adult stages) limited prey numbers more than predators that depredated only specific life stages (e.g. solely during the nest phase). The Red Fox and non-native mammals (e.g. the American Mink Neovison vison) were frequently identified as numerically limiting their prey species. Our review has identified predator-prey interactions that are particularly likely to result in population declines of prey species. In the short term, traditional predator-management techniques (e.g. lethal control or fencing to reduce predation by a small number of predator species) could be used to protect these vulnerable species. However, as these techniques are costly and time-consuming, we advocate that future research should identify land-use practices and landscape configurations that would reduce predator numbers and predation rates.

RevDate: 2018-10-26

Stow MK, Vernouillet A, DM Kelly (2018)

Neophobia does not account for motoric self-regulation performance as measured during the detour-reaching cylinder task.

Animal cognition, 21(4):565-574.

The ability to restrain a prepotent response in favor of a more adaptive behavior, or to exert inhibitory control, has been used as a measure of a species' cognitive abilities. Inhibitory control defines a spectrum of behaviors varying in complexity, ranging from self-control to motoric self-regulation. Several factors underlying inhibitory control have been identified, however, the influence of neophobia (i.e., aversion to novelty) on inhibitory control has not received much attention. Neophobia is known to affect complex cognitive abilities, but whether neophobia also influences more basic cognitive abilities, such as motoric self-regulation, has received less attention. Further, it remains unclear whether an individual's response to novelty is consistent across different paradigms purported to assess neophobia. We tested two North American corvid species, black-billed magpies (Pica hudsonia) and California scrub jays (Aphelocoma californica) using two well-established neophobia paradigms to assess response stability between contexts. We then evaluated neophobia scores against the number of trials needed to learn a motoric self-regulation task, as well as subsequent task performance. Neophobia scores did not correlate across paradigms, nor did the responses during either paradigm account for motoric self-regulation performance.

RevDate: 2019-03-18
CmpDate: 2018-10-02

Fronzetti Colladon A, F Grippa (2018)

The Importance of Being Honest: Correlating Self-Report Accuracy and Network Centrality with Academic Performance.

The Journal of psychology, 152(5):304-324.

This study investigates the correlation of self-report accuracy with academic performance. The sample was composed of 289 undergraduate students (96 senior and 193 junior) enrolled in two engineering classes. Age ranged between 22 and 24 years, with a slight over representation of male students (53%). Academic performance was calculated based on students' final grades in each class. The tendency to report inaccurate information was measured at the end of the Raven Progressive Matrices Test, by asking students to report their exact finishing times. We controlled for gender, age, personality traits, intelligence, and past academic performance. We also included measures of centrality in their friendship, advice and trust networks. Correlation and multiple regression analyses results indicate that lower achieving students were significantly less accurate in self-reporting data. We also found that being more central in the advice network was correlated with higher performance (r = .20, p < .001). The results are aligned with existing literature emphasizing the individual and relational factors associated with academic performance and, pending future studies, may be utilized to include a new metric of self-report accuracy that is not dependent on academic records.

RevDate: 2019-05-14

Monshizadeh L, Vameghi R, Sajedi F, et al (2018)

Comparison of Social Interaction between Cochlear-Implanted Children with Normal Intelligence Undergoing Auditory Verbal Therapy and Normal-Hearing Children: A Pilot Study.

The journal of international advanced otology, 14(1):34-38.

OBJECTIVE: A cochlear implant is a device that helps hearing-impaired children by transmitting sound signals to the brain and helping them improve their speech, language, and social interaction. Although various studies have investigated the different aspects of speech perception and language acquisition in cochlear-implanted children, little is known about their social skills, particularly Persian-speaking cochlear-implanted children. Considering the growing number of cochlear implants being performed in Iran and the increasing importance of developing near-normal social skills as one of the ultimate goals of cochlear implantation, this study was performed to compare the social interaction between Iranian cochlear-implanted children who have undergone rehabilitation (auditory verbal therapy) after surgery and normal-hearing children.

MATERIALS AND METHODS: This descriptive-analytical study compared the social interaction level of 30 children with normal hearing and 30 with cochlear implants who were conveniently selected. The Raven test was administered to the both groups to ensure normal intelligence quotient. The social interaction status of both groups was evaluated using the Vineland Adaptive Behavior Scale, and statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 21.

RESULTS: After controlling age as a covariate variable, no significant difference was observed between the social interaction scores of both the groups (p > 0.05). In addition, social interaction had no correlation with sex in either group.

CONCLUSION: Cochlear implantation followed by auditory verbal rehabilitation helps children with sensorineural hearing loss to have normal social interactions, regardless of their sex.

RevDate: 2018-12-02
CmpDate: 2018-05-28

Hammer MP, Allen GR, Martin KC, et al (2018)

Revision of the Australian Wet Tropics endemic rainbowfish genus Cairnsichthys (Atheriniformes: Melanotaeniidae), with description of a new species.

Zootaxa, 4413(2):271-294 pii:zootaxa.4413.2.3.

The freshwater melanotaeniid genus Cairnsichthys is endemic to a relatively small area of specialised habitat within the Wet Tropics bioregion of north-eastern Queensland, Australia. It was previously considered as monotypic, including only a single species, C. rhombosomoides (Nichols Raven, 1928). The recent discovery of an apparently-isolated population in the Daintree rainforest, approximately 120 km north of the known range extent, prompted a detailed investigation of its taxonomic status using a combined lines of evidence approach. We provide compelling evidence from multiple nuclear genetic markers (52 allozyme loci), mitochondrial DNA sequence data (1141 bp cytochrome b) and morphology (examination of a suite of 38 morphometric and meristic characters) that supports north-south splitting of C. rhombosomoides. Accordingly, we describe the northern population as a distinct species, C. bitaeniatus sp. nov., on the basis of 25 specimens, 34.7-65.6 mm SL. The new species differs morphologically primarily by having a more slender and narrow shape, featuring a flatter, straighter predorsal profile and shorter second dorsal fin base; possession of slightly smaller scales, reflected in higher counts of lateral scales and predorsal scales; typically more vertebrae; and colour differences including a more robust, short black stripe across the upper operculum, a pronounced yellow patch on the anteroventral body and usually a more conspicuous second dark stripe on the lower body, with adult males generally having yellowish compared to reddish fins. We also provide a generic diagnosis for Cairnsichthys and a redescription of C. rhombosomoides. Information on the known distribution, habitats and conservation status of species in the genus is summarised, the new species being of particular concern as a narrow range endemic with specific environmental requirements.

RevDate: 2019-04-01
CmpDate: 2019-02-28

Duque JF, Leichner W, Ahmann H, et al (2018)

Mesotocin influences pinyon jay prosociality.

Biology letters, 14(4):.

Many species exhibit prosocial behaviour, in which one individual's actions benefit another individual, often without an immediate benefit to itself. The neuropeptide oxytocin is an important hormonal mechanism influencing prosociality in mammals, but it is unclear whether the avian homologue mesotocin plays a similar functional role in birds. Here, we experimentally tested prosociality in pinyon jays (Gymnorhinus cyanocephalus), a highly social corvid species that spontaneously shares food with others. First, we measured prosocial preferences in a prosocial choice task with two different pay-off distributions: Prosocial trials delivered food to both the subject and either an empty cage or a partner bird, whereas Altruism trials delivered food only to an empty cage or a partner bird (none to subject). In a second experiment, we examined whether administering mesotocin influenced prosocial preferences. Compared to choices in a control condition, we show that subjects voluntarily delivered food rewards to partners, but only when also receiving food for themselves (Prosocial trials), and administration of high levels of mesotocin increased these behaviours. Thus, in birds, mesotocin seems to play a similar functional role in facilitating prosocial behaviours as oxytocin does in mammals, suggesting an evolutionarily conserved hormonal mechanism for prosociality.

RevDate: 2018-11-14

Brecht KF, Ostojić L, Legg EW, et al (2018)

Difficulties when using video playback to investigate social cognition in California scrub-jays (Aphelocoma californica).

PeerJ, 6:e4451.

Previous research has suggested that videos can be used to experimentally manipulate social stimuli. In the present study, we used the California scrub-jays' cache protection strategies to assess whether video playback can be used to simulate conspecifics in a social context. In both the lab and the field, scrub-jays are known to exhibit a range of behaviours to protect their caches from potential pilferage by a conspecific, for example by hiding food in locations out of the observer's view or by re-caching previously made caches once the observer has left. Here, we presented scrub-jays with videos of a conspecific observer as well as two non-social conditions during a caching period and assessed whether they would cache out of the observer's "view" (Experiment 1) or would re-cache their caches once the observer was no longer present (Experiment 2). In contrast to previous studies using live observers, the scrub-jays' caching and re-caching behaviour was not influenced by whether the observer was present or absent. These findings suggest that there might be limitations in using video playback of social agents to mimic real-life situations when investigating corvid decision making.

RevDate: 2018-11-14

Boeckle M, Szipl G, T Bugnyar (2018)

Raven food calls indicate sender's age and sex.

Frontiers in zoology, 15:5.

Background: Acoustic parameters of animal signals have been shown to correlate with various phenotypic characteristics of the sender. These acoustic characteristics can be learned and categorized and thus are a basis for perceivers' recognition abilities. One of the most demanding capacities is individual recognition, achievable only after repeated interactions with the same individual. Still, class-level recognition might be potentially important to perceivers who have not previously encountered callers but can classify unknown individuals according to the already learned categories. Especially for species with high fission-fusion dynamics that repeatedly encounter unknown individuals it may be advantageous to develop class-level recognition. We tested whether frequency-, temporal-, and amplitude-related acoustic parameters of vocalizations emitted by ravens, a species showing high fission-fusion dynamics in non-breeder aggregations, are connected to phenotypic characteristics and thus have the potential for class-level recognition.

Results: The analysis of 418 food calls revealed that some components summarizing acoustic parameters were differentiated by age-classes and sex.

Conclusions: Together, the results provide evidence for the co-variation of vocal characteristics and respective sex and age categories, a prerequisite for class-level recognition in perceivers. Perceivers that are ignorant of the caller's identity can thus potentially recognize these class-level differences for decision-making processes in feeding contexts.

RevDate: 2019-07-30
CmpDate: 2019-07-30

Luo Y, Zhang L, Teng Z, et al (2018)

A parasitism-mutualism-predation model consisting of crows, cuckoos and cats with stage-structure and maturation delays on crows and cuckoos.

Journal of theoretical biology, 446:212-228.

In this paper, a parasitism-mutualism-predation model is proposed to investigate the dynamics of multi-interactions among cuckoos, crows and cats with stage-structure and maturation time delays on cuckoos and crows. The crows permit the cuckoos to parasitize their nestlings (eggs) on the crow chicks (eggs). In return, the cuckoo nestlings produce a malodorous cloacal secretion to protect the crow chicks from predation by the cats, which is apparently beneficial to both the crow and cuckoo population. The multi-interactions, i.e., parasitism and mutualism between the cuckoos (nestlings) and crows (chicks), predation between the cats and crow chicks are modeled both by Holling-type II and Beddington-DeAngelis-type functional responses. The existence of positive equilibria of three subsystems of the model are discussed. The criteria for the global stability of the trivial equilibrium are established by the Krein-Rutman theorem and other analysis methods. Moreover, the threshold dynamics for the coexistence and weak persistence of the model are obtained, and we show, both analytically and numerically, that the stabilities of the interior equilibria may change with the increasing maturation time delays. We find there exists an evident difference in the dynamical properties of the parasitism-mutualism-predation model based on whether or not we consider the effects of stage-structure and maturation time delays on cuckoos and crows. Inclusion of stage structure results in many varied dynamical complexities which are difficult to encompass without this inclusion.

RevDate: 2018-11-14

Pesendorfer MB, Sillett TS, SA Morrison (2017)

Spatially biased dispersal of acorns by a scatter-hoarding corvid may accelerate passive restoration of oak habitat on California's largest island.

Current zoology, 63(4):363-367.

Scatter hoarding by corvids (crows, jays, magpies, and nutcrackers) provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germination and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns (Quercus spp.) on Santa Cruz Island. We use a large behavioral data set on the birds' behavior in combination with seedling surveys and spatial analysis to determine whether 1) island scrub jays disproportionally cache seeds in specific habitat types, and 2) whether the preferred habitat type is suitable for oak regeneration. Our results show that the jays nonrandomly cache acorns across the landscape; they use chaparral and coastal sage scrub disproportionally while avoiding open and grassy areas. The areas used most often for caching were also the areas with the highest oak seedling densities. We discuss the potential role of these findings for the recovery of Santa Cruz Island's oak habitat since the 1980s.

RevDate: 2018-11-13
CmpDate: 2018-06-11

Ashton BJ, Ridley AR, Edwards EK, et al (2018)

Cognitive performance is linked to group size and affects fitness in Australian magpies.

Nature, 554(7692):364-367.

The social intelligence hypothesis states that the demands of social life drive cognitive evolution. This idea receives support from comparative studies that link variation in group size or mating systems with cognitive and neuroanatomical differences across species, but findings are contradictory and contentious. To understand the cognitive consequences of sociality, it is also important to investigate social variation within species. Here we show that in wild, cooperatively breeding Australian magpies, individuals that live in large groups show increased cognitive performance, which is linked to increased reproductive success. Individual performance was highly correlated across four cognitive tasks, indicating a 'general intelligence factor' that underlies cognitive performance. Repeated cognitive testing of juveniles at different ages showed that the correlation between group size and cognition emerged in early life, suggesting that living in larger groups promotes cognitive development. Furthermore, we found a positive association between the task performance of females and three indicators of reproductive success, thus identifying a selective benefit of greater cognitive performance. Together, these results provide intraspecific evidence that sociality can shape cognitive development and evolution.

RevDate: 2018-11-27
CmpDate: 2018-11-27

Stanford R, Lockley MG, Tucker C, et al (2018)

A diverse mammal-dominated, footprint assemblage from wetland deposits in the Lower Cretaceous of Maryland.

Scientific reports, 8(1):741.

A newly discovered assemblage of predominantly small tracks from the Cretaceous Patuxent Formation at NASA's Goddard Space Flight Center, Maryland, reveals one of the highest track densities and diversities ever reported (~70 tracks, representing at least eight morphotypes from an area of only ~2 m2). The assemblage is dominated by small mammal tracks including the new ichnotxon Sederipes goddardensis, indicating sitting postures. Small crow-sized theropod trackways, the first from this unit, indicate social trackmakers and suggest slow-paced foraging behavior. Tracks of pterosaurs, and other small vertebrates suggest activity on an organic-rich substrate. Large well-preserved sauropod and nodosaurs tracks indicate the presence of large dinosaurs. The Patuxent Formation together with the recently reported Angolan assemblage comprise the world's two largest Mesozoic mammal footprint assemblages. The high density of footprint registration at the NASA site indicates special preservational and taphonomic conditions. These include early, penecontemporaneous deposition of siderite in organic rich, reducing wetland settings where even the flesh of body fossils can be mummified. Thus, the track-rich ironstone substrates of the Patuxent Formation, appear to preserve a unique vertebrate ichnofacies, with associated, exceptionally-preserved body fossil remains for which there are currently no other similar examples preserved in the fossil record.

RevDate: 2018-11-13

Maziarz M, Piggott C, M Burgess (2018)

Predator recognition and differential behavioural responses of adult wood warblers Phylloscopus sibilatrix.

Acta ethologica, 21(1):13-20.

Birds often engage in nest defence against predators to improve breeding success, but defence efficiency requires the capability to assess the threat level posed by potential predators. For species with low breeding-site tenacity, which may encounter varying occurrence and density of predators in different areas, threat recognition could be compromised due to naivety, and so predator recognition may focus on broad key features to diminish the risk of misidentification. We experimentally tested this hypothesis by recording behavioural reactions of the nomadic wood warbler Phylloscopus sibilatrix to objects reflecting various levels of threat: least weasel and Eurasian jay taxidermy mounts, an inanimate object and an empty display mount. To assess actual nest predators, we used remote cameras to record predation events at wood warbler nests. As in other studies in Western Europe, Eurasian jay was found to be the main nest predator, with occasional predation by least weasel. The reaction of adult warblers to the models was generally to remain silent and on nests during the incubation stage presumably due to the need to maintain efficient nest camouflage and concealment. During the nestling stage, behavioural responses of adult warblers, calling and suspended feeding of young, showed the strongest effects from the jay taxidermy mount, moderate to the weasel and weakest to the inanimate object and empty mount. As the reaction of wood warblers reflected the degree of genuine threat posed by the predators depicted by the models, we conclude that predator recognition may be present in this species.

RevDate: 2018-05-22
CmpDate: 2018-05-22

Claes R, Muyshondt PGG, Dirckx JJJ, et al (2018)

Do high sound pressure levels of crowing in roosters necessitate passive mechanisms for protection against self-vocalization?.

Zoology (Jena, Germany), 126:65-70.

High sound pressure levels (>120dB) cause damage or death of the hair cells of the inner ear, hence causing hearing loss. Vocalization differences are present between hens and roosters. Crowing in roosters is reported to produce sound pressure levels of 100dB measured at a distance of 1m. In this study we measured the sound pressure levels that exist at the entrance of the outer ear canal. We hypothesize that roosters may benefit from a passive protective mechanism while hens do not require such a mechanism. Audio recordings at the level of the entrance of the outer ear canal of crowing roosters, made in this study, indeed show that a protective mechanism is needed as sound pressure levels can reach amplitudes of 142.3dB. Audio recordings made at varying distances from the crowing rooster show that at a distance of 0.5m sound pressure levels already drop to 102dB. Micro-CT scans of a rooster and chicken head show that in roosters the auditory canal closes when the beak is opened. In hens the diameter of the auditory canal only narrows but does not close completely. A morphological difference between the sexes in shape of a bursa-like slit which occurs in the outer ear canal causes the outer ear canal to close in roosters but not in hens.

RevDate: 2019-05-08
CmpDate: 2019-05-08

St Clair JJH, Klump BC, Sugasawa S, et al (2018)

Hook innovation boosts foraging efficiency in tool-using crows.

Nature ecology & evolution, 2(3):441-444.

The New Caledonian crow is the only non-human animal known to craft hooked tools in the wild, but the ecological benefit of these relatively complex tools remains unknown. Here, we show that crows acquire food several times faster when using hooked rather than non-hooked tools, regardless of tool material, prey type and extraction context. This implies that small changes to tool shape can strongly affect energy-intake rates, highlighting a powerful driver for technological advancement.

RevDate: 2019-01-02
CmpDate: 2019-01-02

Shurulinkov P, Spasov L, Stoyanov G, et al (2018)

Blood parasite infections in a wild population of ravens (Corvus corax) in Bulgaria.

Malaria journal, 17(1):33.

BACKGROUND: Blood parasites have been studied intensely in many families of avian hosts, but corvids, a particularly cosmopolitan family, remain underexplored. Haemosporidian parasites of the common raven (Corvus corax) have not been studied, although it is the largest, most adaptable, and widespread corvid. Genetic sequence data from parasites of ravens can enhance the understanding of speciation patterns and specificity of haemosporidian parasites in corvids, and shed light how these hosts cope with parasite pressure.

METHODS: A baited cage trap was used to catch 86 ravens and a nested PCR protocol was used to amplify a 479 bp fragment of the haemosporidian cytochrome b gene from the samples. The obtained sequences were compared with the MalAvi database of all published haemosporidian lineages and a phylogenetic tree including all detected raven parasites was constructed. An examination of blood smears was performed for assessment of infection intensity.

RESULTS: Twenty blood parasite lineages were recovered from ravens caught in a wild population in Bulgaria. The prevalence of generalist Plasmodium lineages was 49%, and the prevalence of Leucocytozoon lineages was 31%. Out of 13 detected Leucocytozoon lineages six were known from different corvids, while seven others seem to be specific to ravens. A phylogenetic reconstruction suggests that Leucocytozoon lineages of ravens and other corvids are not monophyletic, with some groups appearing closely related to parasites of other host families.

CONCLUSIONS: Several different, morphologically cryptic groups of Leucocytozoon parasites appear to infect corvids. Ravens harbour both generalist corvid Leucocytozoon as well as apparently species-specific lineages. The extraordinary breeding ecology and scavenging lifestyle possibly allow ravens to evade vectors and have relatively low blood parasite prevalence compared to other corvids.

RevDate: 2019-05-14
CmpDate: 2019-05-14

Padget O, Bond SL, Kavelaars MM, et al (2018)

In Situ Clock Shift Reveals that the Sun Compass Contributes to Orientation in a Pelagic Seabird.

Current biology : CB, 28(2):275-279.e2.

Compass orientation is central to the control of animal movement from the scale of local food-caching movements around a familiar area in parids [1] and corvids [2, 3] to the first autumn vector navigation of songbirds embarking on long-distance migration [4-6]. In the study of diurnal birds, where the homing pigeon, Columba livia, has been the main model, a time-compensated sun compass [7] is central to the two-step map-and-compass process of navigation from unfamiliar places, as well as guiding movement via a representation of familiar area landmarks [8-12]. However, its use by an actively navigating wild bird is yet to be shown. By phase shifting an animal's endogenous clock, known as clock-shifting [13-15], sun-compass use can be demonstrated when the animal incorrectly consults the sun's azimuthal position while homing after experimental displacement [15-17]. By applying clock-shift techniques at the nest of a wild bird during natural incubation, we show here that an oceanic navigator-the Manx shearwater, Puffinus puffinus-incorporates information from a time-compensated sun compass during homeward guidance to the breeding colony after displacement. Consistently with homing pigeons navigating within their familiar area [8, 9, 11, 18], we find that the effect of clock shift, while statistically robust, is partial in nature, possibly indicating the incorporation of guidance from landmarks into movement decisions.

RevDate: 2018-11-13
CmpDate: 2018-01-29

Morrison R, D Reiss (2018)

Precocious development of self-awareness in dolphins.

PloS one, 13(1):e0189813.

Mirror-self recognition (MSR) is a behavioral indicator of self-awareness in young children and only a few other species, including the great apes, dolphins, elephants and magpies. The emergence of self-awareness in children typically occurs during the second year and has been correlated with sensorimotor development and growing social and self-awareness. Comparative studies of MSR in chimpanzees report that the onset of this ability occurs between 2 years 4 months and 3 years 9 months of age. Studies of wild and captive bottlenose dolphins (Tursiops truncatus) have reported precocious sensorimotor and social awareness during the first weeks of life, but no comparative MSR research has been conducted with this species. We exposed two young bottlenose dolphins to an underwater mirror and analyzed video recordings of their behavioral responses over a 3-year period. Here we report that both dolphins exhibited MSR, indicated by self-directed behavior at the mirror, at ages earlier than generally reported for children and at ages much earlier than reported for chimpanzees. The early onset of MSR in young dolphins occurs in parallel with their advanced sensorimotor development, complex and reciprocal social interactions, and growing social awareness. Both dolphins passed subsequent mark tests at ages comparable with children. Thus, our findings indicate that dolphins exhibit self-awareness at a mirror at a younger age than previously reported for children or other species tested.

RevDate: 2019-04-03
CmpDate: 2019-04-03

Subias L, Griffin AS, D Guez (2019)

Inference by exclusion in the red-tailed black cockatoo (Calyptorhynchus banksii).

Integrative zoology, 14(2):193-203.

Inference by exclusion is the ability to select a given option by excluding the others. When designed appropriately, tests of this ability can reveal choices that cannot be explained by associative processes. Over the past decade, exclusion reasoning has been explored in several non-human taxonomic groups, including birds, mainly in Corvids and Parrots. To increase our understanding of the taxonomic distribution of exclusion reasoning and, therefore, its evolution, we investigated exclusion performances in red-tailed black cockatoos (Calyptorhynchus banksii), an Australian relative of the Goffin cockatoo (Cacatua goffini), using a food-finding task. Cockatoos were required to find a food item hidden in 1 of the 2 experimenter's hands. Following training sessions in which they reliably selected the closed baited hand they had just been shown open, each individual was tested on 4 different conditions. Critical to demonstrating exclusion reasoning was the condition in which they were shown the empty hand and then offered a choice of both closed hands. The performance of all birds was above chance on all experimental conditions but not on an olfactory and/or cuing control condition. The results suggest that the birds might be able to infer by exclusion, although an explanation based on rule learning cannot be excluded. This first experiment in red-tailed black cockatoo highlights the potential of this species as a model to study avian cognition and paves the pathway for future investigations.

RevDate: 2018-11-13

Szipl G, Ringler E, Spreafico M, et al (2017)

Calls during agonistic interactions vary with arousal and raise audience attention in ravens.

Frontiers in zoology, 14:57.

Background: Acoustic properties of vocalizations can vary with the internal state of the caller, and may serve as reliable indicators for a caller's emotional state, for example to prevent conflicts. Thus, individuals may associate distinct characteristics in acoustic signals of conspecifics with specific social contexts, and adjust their behaviour accordingly to prevent escalation of conflicts. Common ravens (Corvus corax) crowd-forage with individuals of different age classes, sex, and rank, assemble at feeding sites, and engage in agonistic interactions of varying intensity. Attacked individuals frequently utter defensive calls in order to appease the aggressor. Here, we investigated if acoustic properties of defensive calls change with varying levels of aggression, and if bystanders respond to these changes.

Results: Individuals were more likely to utter defensive calls when the attack involved contact aggression, and when the attacker was higher in rank than the victim. Defensive calls produced during intense conflicts were longer and uttered at higher rates, and showed higher fundamental frequency- and amplitude-related measures than calls uttered during low-intensity aggression, indicating arousal-based changes in defensive calls. Playback experiments showed that ravens were more likely to react in response to defensive calls with higher fundamental frequency by orientating towards the speakers as compared to original calls and calls manipulated in duration.

Conclusions: Arousal-based changes are encoded in acoustic parameters of defensive calls in attacked ravens, and bystanders in the audience pay attention to the degree of arousal in attacked conspecifics. Our findings imply that common ravens can regulate conflicts with conspecifics by means of vocalizations, and are able to gather social knowledge from conspecific calls.

RevDate: 2019-04-11

Rubio E, Sanllorente O, Tieleman BI, et al (2018)

Fecal sacs do not increase nest predation in a ground nester.

Journal of ornithology, 159(4):985-990.

Most altricial birds remove their nestlings' feces from the nest, but the evolutionary forces driving this behavior are poorly understood. A possible adaptive explanation for this could be that birds avoid the attraction of nest predators to their nests due to the visual or olfactory cues produced by feces (nest predation hypothesis). This hypothesis has received contrasting support indicating that additional experimental studies are needed, particularly with respect to the visual component of fecal sacs. To test this hypothesis, we conducted an experiment manipulating the presence of fecal sacs on inactive Woodlark (Lullula arborea) nests. This ground nester has highly cryptic nests that are mainly depredated by visually oriented nest predators (i.e., corvids) in our study population, making it an excellent system to test for the nest predation hypothesis. Our results showed that the presence of fecal sacs in the nest does not seem to be an important factor explaining nest predation. Interestingly, the effect of nest concealment, the most important factor explaining nest predation in Woodlark nests, depended on whether the nest was depredated the previous year or not, supporting the importance of using different nesting sites between years. Our findings indicate that this important nest sanitation behavior is not likely motivated by nest predation and highlight the need to explore alternative selective pressures in this context.

RevDate: 2018-12-02
CmpDate: 2018-07-06

Gallup GG, JR Anderson (2018)

The "olfactory mirror" and other recent attempts to demonstrate self-recognition in non-primate species.

Behavioural processes, 148:16-19.

The recent attempt by Horowitz (2017) to develop an "olfactory mirror" test of self-recognition in domestic dogs raises some important questions about the kinds of data that are required to provide definitive evidence for self-recognition in dogs and other species. We conclude that the "olfactory mirror" constitutes a compelling analog to the mark test for mirror self-recognition in primates, but despite claims to the contrary neither dogs, elephants, dolphins, magpies, horses, manta rays, squid, nor ants have shown compelling, reproducible evidence for self-recognition in any modality.

RevDate: 2019-06-20
CmpDate: 2019-06-20

van Casteren A (2017)

Tool Use: Crows Craft the Right Tool for the Job.

Current biology : CB, 27(24):R1314-R1316.

New research into tool crafting in New Caledonian crows has uncovered factors that influence tool shape and the foraging advantages that these characteristics confer.

RevDate: 2018-11-26
CmpDate: 2018-11-26

Grúz A, Déri J, Szemerédy G, et al (2018)

Monitoring of heavy metal burden in wild birds at eastern/north-eastern part of Hungary.

Environmental science and pollution research international, 25(7):6378-6386.

Concentrations of different heavy metals (As, Cd, Cr, Cu, Hg, Pb, Zn) were examined in the contour feathers of long-eared owl (Asio otus), little owl (Athene noctua), tawny owl (Strix aluco), barn owl (Tyto alba), Eurasian sparrowhawk (Accipiter nisus), rook (Corvus frugilegus), hooded crow (Corvus cornix), carrion crow (Corvus corone), common buzzard (Buteo buteo) and barn swallow (Hirundo rustica). The samples were collected from the Hortobágyi Madárpark (Bird Hospital Foundation) in Hungary. The bird species were classified into six groups based on their nourishment. Feathers were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The aim of our study was to determine the concentration of the above-mentioned heavy metals in the six different groups and to compare them by the groups, to find a possible connection between the concentrations and the age of birds and to get some information about the heavy metal burden of the environment. The highest As concentration was measured in little owl (0.65 ± 0.56 mg/kg). The highest Cd, Cr and Pb concentration was found in the feathers of barn swallow (0.13 ± 0.06 mg/kg; 1.69 ± 0.44 mg/kg; 5.36 ± 1.46 mg/kg), while the highest Cu and Hg concentration (65.45 ± 17.66 mg/kg; 2.72 ± 1.08 mg/kg) in sparrowhawk feathers and the highest Zn concentration in owls (157.21 ± 57.3 mg/kg). Statistically significant difference has been determined between the juvenile and adult crows in the case of Cd (p = 0.011). The higher concentration was measured in adults (0.14 ± 0.04 mg/kg) than that in juveniles (0.08 ± 0.02 mg/kg). Based on our results, the examined area is not contaminated by these heavy metals on that level, which can cause any adverse effect or poisoning in birds, so this region is safe to wildlife.

RevDate: 2018-11-13

Kabadayi C, Jacobs I, M Osvath (2017)

The Development of Motor Self-Regulation in Ravens.

Frontiers in psychology, 8:2100.

Inhibitory control refers to the ability to stop impulses in favor of more appropriate behavior, and it constitutes one of the underlying cognitive functions associated with cognitive flexibility. Much attention has been given to cross-species comparisons of inhibitory control; however, less is known about how and when these abilities develop. Mapping the ontogeny of inhibitory control in different species may therefore reveal foundational elements behind cognitive processes and their evolution. In this study, we tested the development of motor self-regulation in raven chicks (Corvus corax), using two detour tasks that required inhibition of motor impulses to directly reach for a visible reward behind a barrier. One task included a mesh barrier, which partly occluded the reward, and the other task used a completely transparent barrier, the cylinder task. The results suggest that the more visible a reward is, the more difficult it is to inhibit motor impulses toward it, and further, that this inhibitory challenge gradually decreases during development. The mesh barrier is reliably detoured before the animals pass the task with the wholly transparent cylinder. As the majority of the birds begun testing as nestlings, and as we provided them with experiences they normally would not receive in a nest, it is likely that they showed the earliest possible onset of these skills. A control subject, tested at a later age, showed that the mesh detours required no particular training, but that tasks including complete transparency likely require more specific experiences. Adult ravens without explicit training are highly proficient in inhibitory detour tasks, and, together with chimpanzees, they are the best performers of all tested species in the cylinder task. Our results suggest that their skills develop early in life, around their third month. Their developmental pattern of inhibitory skills for detours resembles that of children and rhesus macaques, albeit the pace of development is markedly faster in ravens. Investigating the development of cognition is crucial to understanding its foundations within and across species.

RevDate: 2019-05-16

Taufique SKT, Prabhat A, V Kumar (2018)

Constant light environment suppresses maturation and reduces complexity of new born neuron processes in the hippocampus and caudal nidopallium of a diurnal corvid: Implication for impairment of the learning and cognitive performance.

Neurobiology of learning and memory, 147:120-127.

Periodic day-night environment shapes the temporal pattern in the behaviour and physiology (e.g. 24-h activity-rest and sleep-wake cycles) and the advanced brain function, such as learning, memory and decision making. In a previous study, we showed the abolition of 24-h rhythm in the activity-rest pattern, and an attenuated cognitive performance in diurnal Indian house crows (Corvus splendens) under constant light (no-night; LL) environment. Present study extended this, and investigated LL-induced effects on the neurogenesis (birth, maturation and neurite complexity of new born neurons) in the hippocampus and caudal nidopallium, the brain regions directly associated with learning and cognition in birds. We performed immunohistochemistry of doublecortin (DCX; a neurogenesis marker) and tyrosine hydroxylase (TH, a key enzyme of the dopamine biosynthesis) in the brain section containing hippocampus or caudal nidopallium of Indian house crows exposed for 2 weeks to LL, with controls maintained under 12L:12D. As expected, crows showed arrhythmicity with a significantly reduced rest period in the 24-h activity-rest pattern, and a decreased cognitive performance when tested for the spatial and pattern association learning tasks under LL. Importantly, there was a significant decrease in DCX-immunoreactive (ir) cells and, as shown by Sholl analysis, in the complexity of DCX-ir neurites in both, the hippocampus and caudal nidopallium of crows under LL, as compared to those under 12L:12D. The anatomical proximity of DCX-ir neurons with TH-ir fibers suggested a functional association of the new born hippocampal and caudal nidopallial neurons with the learning, and perhaps cognition in Indian house crows. These results give insights into possible impact of the loss of night on brain health and functions in an emerging ecosystem in which other diurnal species including humans may be inadvertently exposed to an illuminated night, such as in an overly lighted metropolitan urban habitat.

RevDate: 2018-08-03
CmpDate: 2018-08-03

Sugasawa S, Klump BC, St Clair JJH, et al (2017)

Causes and Consequences of Tool Shape Variation in New Caledonian Crows.

Current biology : CB, 27(24):3885-3890.e4.

Hominins have been making tools for over three million years [1], yet the earliest known hooked tools appeared as recently as 90,000 years ago [2]. Hook innovation is likely to have boosted our ancestors' hunting and fishing efficiency [3], marking a major transition in human technological evolution. The New Caledonian crow is the only non-human animal known to craft hooks in the wild [4, 5]. Crows manufacture hooked stick tools in a multi-stage process, involving the detachment of a branch from suitable vegetation; "sculpting" of a terminal hook from the nodal joint; and often additional adjustments, such as length trimming, shaft bending, and bark stripping [4, 6, 7]. Although tools made by a given population share key design features [4, 6, 8], they vary appreciably in overall shape and hook dimensions. Using wild-caught, temporarily captive crows, we experimentally investigated causes and consequences of variation in hook-tool morphology. We found that bird age, manufacture method, and raw-material properties influenced tool morphology, and that hook geometry in turn affected crows' foraging efficiency. Specifically, hook depth varied with both detachment technique and plant rigidity, and deeper hooks enabled faster prey extraction in the provided tasks. Older crows manufactured tools of distinctive shape, with pronounced shaft curvature and hooks of intermediate depth. Future work should explore the interactive effects of extrinsic and intrinsic factors on tool production and deployment. Our study provides a quantitative assessment of the drivers and functional significance of tool shape variation in a non-human animal, affording valuable comparative insights into early hominin tool crafting [9].

RevDate: 2018-12-02
CmpDate: 2018-07-23

Elderbrock EK, Small TW, SJ Schoech (2018)

Influence of corticosterone treatment on nestling begging in Florida scrub-jays (Aphelocoma coerulescens).

General and comparative endocrinology, 259:213-222.

Altricial young are dependent on adults for protection and food, and they display nutritional need by begging to elicit feeding from parents. Begging at high levels can be energetically expensive and attract predators; thus, an individual must balance its nutritional needs with these potential costs. Further, because a parent is limited in the amount of food it can provide, begging can contribute to both parent-offspring conflict and sibling-sibling competition. Many extrinsic and intrinsic factors may contribute to begging behavior. One intrinsic factor of interest is corticosterone (CORT), a metabolic hormone hypothesized to play a role in regulating a nestling's begging behavior. We investigated the hypothesis that increased exposure to CORT influences nestling begging behavior in an altricial species, the Florida scrub-jay (Aphelocoma coerulescens). We treated one nestling per treatment nest with a twice-daily dose of exogenous hormone via a CORT-injected waxworm, whereas a second individual received a vehicle-injected waxworm. We monitored individual nestling and adult behavior at all nests with the use of high-definition video cameras on several days during treatment. We found no difference in begging rate between CORT fed and vehicle fed nestlings within a treatment nest. Further, to determine whether CORT treatment had indirect effects on the entire brood, we monitored additional nests, in which nestlings were not manipulated. When treatment and controls were compared, overall begging rates of nestlings in treatment nests were greater than those in control nests. This result suggests that CORT treatment of an individual altered its behavior, as well as that of its siblings.

RevDate: 2019-07-08
CmpDate: 2019-07-08

Danel S, Osiurak F, AMP von Bayern (2017)

From the Age of 5 Humans Decide Economically, Whereas Crows Exhibit Individual Preferences.

Scientific reports, 7(1):17043.

Human societies greatly depend on tools, which spare us considerable time and effort. Humans might have evolved a bias to employ tools, using them even when they are unnecessary. This study aimed to investigate whether adult humans and a distantly related habitually tool-using vertebrate species, the New Caledonian crow (Corvus moneduloides), use tools depending on their necessity. In addition, children aged 3 to 5 years were examined to investigate the developmental pattern. The task involved choosing between using a body part (i.e. crows: beak; humans: hand) or a tool for retrieving a reward from a box. All subjects were tested in two conditions. In the Body+/Tool- condition, using the body was more efficient than using the tool, and conversely in the Body-/Tool+ condition. Our results suggest that the capacity to employ tools economically develops late in humans. Crows, however, failed to choose economically. At the individual level, some subjects exhibited striking individual preferences for either using a tool or their beak throughout the task. Whether such biases depend on individual experience or whether they are genetically determined remains to be investigated. Our findings provide new insights about tool use and its cognitive implementation in two outstanding tool-using taxa.

RevDate: 2018-11-13
CmpDate: 2018-01-26

Found R (2017)

Interactions between cleaner-birds and ungulates are personality dependent.

Biology letters, 13(11):.

While a growing body of literature explores the ecological implications of consistent individual variation in the behaviour of wildlife, few studies have looked at the reciprocal influences of personality within interspecific interactions, despite the potentially significant impacts on biodiversity. Here I used two species involved in cleaner-bird behaviour-black-billed magpies (Pica pica) and Rocky mountain elk (Cervus canadensis)-to show that the exhibition of mutualistic behaviour can depend on the personality of the individual involved. I recorded suites of correlated behaviours in both elk and magpies to derive personality gradients from 'shy' to 'bold', which I compared with observations of interspecific interactions. I measured each half of this mutualistic relationship separately. I found that bold elk were more likely to aggressively reject magpie landings, while shy elk allowed magpies to land and groom them. Contrastingly, I found it was bold magpies that were willing to risk landings, while shy magpies rarely attempted landings. These results show that the exhibition of interspecific behaviour is predicated on the personality of the individuals, and thus likely contributes to the selection and maintenance of personality variation within populations.

RevDate: 2018-12-11
CmpDate: 2018-12-11

Hartmann K, Veit L, A Nieder (2018)

Neurons in the crow nidopallium caudolaterale encode varying durations of visual working memory periods.

Experimental brain research, 236(1):215-226.

Adaptive sequential behaviors rely on the bridging and integration of temporally separate information for the realization of prospective goals. Corvids' remarkable behavioral flexibility is thought to depend on the workings of the nidopallium caudolaterale (NCL), a high-level avian associative forebrain area. We trained carrion crows to remember visual items for three alternating delay durations in a delayed match-to-sample task and recorded single-unit activity from the NCL. Sample-selective delay activity, a correlate of visual working memory, was maintained throughout different working memory durations. Delay responses remained selective for the same preferred sample item across blocks with different delay durations. However, selectivity strength decreased with increasing delay durations, mirroring worsened behavioral performance with longer memory delays. Behavioral relevance of delay activity was further evidenced by reduced encoding of the preferred sample item during error trials. In addition, NCL neurons adapted their time-dependent discharges to blocks of different memory durations, so that delay duration could be successfully classified based on population activity a few trials after the delay duration switched. Therefore, NCL neurons not only maintain information from individual trials, but also keep track of the duration for which this information is needed in the context of the task. These results strengthen the role of corvid NCL in maintaining working memory for flexible control of temporally extended goal-directed behavior.

RevDate: 2018-11-13
CmpDate: 2018-05-10

Herzberg D (2017)

Entitled to Addiction?: Pharmaceuticals, Race, and America's First Drug War.

Bulletin of the history of medicine, 91(3):586-623.

This article rethinks the formative decades of American drug wars through a social history of addiction to pharmaceutical narcotics, sedatives, and stimulants in the first half of the twentieth century. It argues, first, that addiction to pharmaceutical drugs is no recent aberration; it has historically been more extensive than "street" or illicit drug use. Second, it argues that access to psychoactive pharmaceuticals was a problematic social entitlement constructed as distinctively medical amid the racialized reforms of the Progressive Era. The resulting drug control regime provided inadequate consumer protection for some (through the FDA), and overly punitive policing for others (through the FBN). Instead of seeing these as two separate stories-one a liberal triumph and the other a repressive scourge-both should be understood as part of the broader establishment of a consumer market for drugs segregated by class and race like other consumer markets developed in the era of Progressivism and Jim Crow.

RevDate: 2018-12-02
CmpDate: 2018-04-20

Hill SD, Aryal A, Pawley MDM, et al (2018)

So much for the city: Urban-rural song variation in a widespread Asiatic songbird.

Integrative zoology, 13(2):194-205.

Song plays a fundamental role in intraspecific communication in songbirds. The temporal and structural components of songs can vary in different habitats. These include urban habitats where anthropogenic sounds and alteration of habitat structure can significantly affect songbird vocal behavior. Urban-rural variations in song complexity, song length and syllable rate are not fully understood. In this study, using the oriental magpie-robin (Copsychus saularis) as a model, we investigated urban-rural variation in song complexity, song length, syllable rate, syllable length and inter-syllable interval. Comparing urban and rural songs from 7 countries across its natural Asiatic range (Bangladesh, India, Malaysia, Nepal, Singapore, Sri Lanka and Thailand), we found no significant differences in oriental magpie-robin song complexity. However, we found significant differences in temporal song variables between urban and rural sites. Longer songs and inter-syllable intervals in addition to slower syllable rates within urban sites contributed the most to this variance. This indicates that the urban environment may have driven production of longer and slower songs to maximize efficient transmission of important song information in urban habitats.

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RJR Experience and Expertise

Researcher

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.

Educator

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.

Administrator

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.

Technologist

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.

Publisher

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.

Speaker

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.

Facilitator

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.

Designer

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

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

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Curriculum Vitae for R J Robbins

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