SEARCH · Search bioRxiv

Results for “Animal Behavior and Cognition”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

bioRxiv2018

Isolated individuals and groups show opposite preferences toward humidity

Cockroaches, like most social arthropods, are led to choose collectively among different alternative resting places. These decisions are modulated by different factors, such as environmental conditions (temperature, relative humidity) and sociality (groups size, nature of communications). The aim of this study is to establish the interplay between environmental conditions and the modulation of the interactions between individuals within a group leading to an inversion of preferences. We show that the preferences of isolated cockroaches and groups of 16 individuals, on the selection of the relative humidity of a shelter are inversed and shed light on the mechanisms involved. We suggest that the relative humidity has a multi-level influence on cockroaches, manifested as an attractant effect at the individual level and as a negative effect at the group level, modulating the interactions.

animal behavior and cognition↗

bioRxiv2018

Sex-specific migration strategies of ospreys (Pandion haliaetus) from Germany

Birds exhibit a wide variety of migration strategies, not only between species, but also within species. Populations might migrate to specific sites outside of the breeding season, but individuals within populations may also exhibit different migration strategies. Young, unexperienced birds may take different routes, visit different sites, and time their annual cycle differently than adults. In turn, within groups of adult birds, there may be a division between the sexes whereby males and females migrate to different sites or, more commonly, at different times. We investigated differences in the migration strategies of male and female ospreys (Pandion haliaetus) from a breeding population in northeastern Germany. An important difference between the sexes was the much earlier leaving of the breeding place by the females compared to the males. The difference in the timing of departure was much more pronounced compared to most other raptor species. The other main difference between the male and female ospreys was the distance that the birds accumulated over the annual cycle, with males generally moving more while at the breeding ground compared with the non-breeding grounds, and the opposite in females. An exception to this observation was two males that migrated to the Iberian Peninsula, that covered longer distances during the non-breeding season. Consequently, individuals accumulated the same distances over the course of an annual cycle, regardless of sex or migration strategy. Unexpectedly, a difference in the timing of the annual cycle between the sexes occurred at the breeding grounds with females leaving 2 to 3 months before the males, long before the young had fledged. Because males migrated much faster and, unlike the females, did not make prolonged stops, their arrival times at the non-breeding grounds were not different. Return migration to the breeding grounds was very similar between the sexes, and even the two males that spent the non-breeding season on the Iberian Peninsula did not arrive before any of the other birds. Thus, a shorter migration distance is not necessarily associated with an advantage with respect to a timely return to the breeding grounds.

animal behavior and cognition↗

bioRxiv2018

Prediction of Choice from Competing Mechanosensory and Choice-Memory Cues During Active Tactile Decision Making

Perceptual decision making is an active process where animals move their sense organs to extract task-relevant information. To investigate how the brain translates sensory input into decisions during active sensation, we developed a mouse active touch task where the mechanosensory input can be precisely measured and that challenges animals to use multiple mechanosensory cues. Mice were trained to localise a pole using a single whisker and to report their decision by selecting one of three choices. Using high-speed imaging and machine vision we estimated whisker-object mechanical forces at millisecond resolution. Mice solved the task by a sensory-motor strategy where both the strength and direction of whisker bending were informative cues to pole location. We found competing influences of immediate sensory input and choice memory on mouse choice. On correct trials, choice could be predicted from the direction and strength of whisker bending, but not from previous choice. In contrast, on error trials, choice could be predicted from previous choice but not from whisker bending. This study shows that animal choices during active tactile decision making can be predicted from mechanosenory and choice-memory signals; and provides a new task, well-suited for future study of the neural basis of active perceptual decisions.\n\nSIGNIFICANCE STATEMENTDue to the difficulty of measuring the sensory input to moving sense organs, active perceptual decision making remains poorly understood. The whisker system provides a way forward since it is now possible to measure the mechanical forces due to whisker-object contact during behaviour. Here we train mice in a novel behavioural task that challenges them to use rich mechanosensory cues, but can be performed using one whisker and enables task-relevant mechanical forces to be precisely estimated. This approach enables rigorous study of how sensory cues translate into action during active, perceptual decision making. Our findings provide new insight into active touch and how sensory/internal signals interact to determine behavioural choices.

animal behavior and cognition↗

bioRxiv2018

Aggregation rule in animal collectives dynamically changes between majority and minority influence

A variety of simple models has been proposed to understand the collective motion of animals. These models can be insightful but lack important elements necessary to predict the motion of each individual in the collective. Adding more detail increases predictability but can make models too complex to be insightful. Here we report that deep attention networks can obtain in a data-driven way a model of collective behavior that is simultaneously predictive and insightful thanks to an organization in modules. The model obtains that interactions between two zebrafish, Danio rerio, in a large groups of 60-100, can be approximately be described as repulsive, attractive or as alignment, but only when moving slowly. At high velocities, interactions correspond only to alignment or alignment mixed with repulsion at close distances. The model also shows that each zebrafish decides where to move by aggregating information from the group as a weighted average over neighbours. Weights are higher for neighbours that are close, in a collision path or moving faster in frontal and lateral locations. These weights effectively select 5 relevant neighbours on average, but this number is dynamical, changing between a single neighbour to up to 12, often in less than a second. Our results suggest that each animal in a group decides by dynamically selecting information from the group.\n\nHighlightsO_LIAt 30 days postfertilization, zebrafish, Danio rerio, can move in very cohesive and predictable large groups\nC_LIO_LIDeep attention networks obtain a predictive and understadable model of collective motion\nC_LIO_LIWhen moving slowly, interations between pairs of zebrafish have clear components of repulsion, attraction and alignment\nC_LIO_LIWhen moving fast, interactions correspond to alignment and a mixture of alignment and repulsion at close distances\nC_LIO_LIZebrafish turn left or right depending on a weighted average of interaction information with other fish, with weights higher for close fish, those in a collision path or those moving fast in front or to the sides\nC_LIO_LIAggregation is dynamical, oscillating between 1 and 12 neighbouring fish, with 5 on average\nC_LI

animal behavior and cognition↗

bioRxiv2018

Visual intensity ratio modulates operant learning responses in larval zebrafish

Larval zebrafish is a promising vertebrate model for understanding neural mechanisms underlying learning and memory. Here, we report on a high-throughput operant learning system for zebrafish larvae and demonstrate that lower visual intensity ratio of the conditioned stimulus to the background can enhance learning ability, highlighted by several behavioral metrics. We further characterize the learning curves as well as memory extinction for each conditioned pattern. Finally, we show how this learning process developed from 7 days old to 10 days old zebrafish.\n\nHighlightsO_LIConditioned visual patterns with lower intensity ratio to the background elicited stronger operant learning responses\nC_LIO_LIMemory extinction was modulated by the visual intensity ratio of the conditioned stimulus to the background\nC_LIO_LIA high-throughput automated system for acquiring and analyzing behavioral data\nC_LI

animal behavior and cognition↗

bioRxiv2018

Sleep regulates visual selective attention in Drosophila

Although sleep-deprivation is known to impair attention in humans and other mammals, the underlying reasons are not well understood, and whether similar effects are present in non-mammalian species is not known. We therefore sought to investigate whether sleep is important for optimising attention in an invertebrate species, the genetic model Drosophila melanogaster. We developed a high-throughput paradigm to measure visual attention in freely-walking Drosophila, using competing foreground/background visual stimuli. We found that whereas sleep-deprived flies could respond normally to either stimulus alone, they were more distracted by background cues in a visual competition task. Other stressful manipulations such as starvation, heat exposure, and mechanical stress had no effects on visual attention in this paradigm. In contrast to sleep-deprivation, providing additional sleep using the GABA-A agonist 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridine-3-ol (THIP) did not affect attention in wild-type flies, but significantly improved attention in the learning mutant dunce. Our results reveal a key function of sleep in optimising attention processes in Drosophila, and establish a behavioural paradigm that can be used to explore the molecular mechanisms involved.\n\nSummary statementSleep deprivation specifically impairs visual selective attention in fruit flies, without affecting behavioural responses to simple visual stimuli.

animal behavior and cognition↗

bioRxiv2018

Does the strength of women’s attraction to male vocal masculinity track changes in steroid hormones?

Recent studies that either used luteinizing hormone tests to confirm the timing of ovulation or measured steroid hormones from saliva have found little evidence that womens preferences for facial or body masculinity track within-subject changes in womens fertility or hormonal status. Fewer studies using these methods have examined womens preferences for vocal masculinity, however, and those that did report mixed results. Consequently, we used a longitudinal design and measured steroid hormones from saliva to test for evidence of hormonal regulation of womens (N=351) preferences for two aspects of male vocal masculinity (low pitch and low formants). Analyses suggested that preferences for masculine pitch, but not masculine formants, may track within-woman changes in estradiol. Although these results present some evidence for the hypothesis that within-subject hormones regulate womens attraction to masculine men, we do not discount the possibility that the effect of estradiol on pitch preferences in the current study is a false positive.

animal behavior and cognition↗

bioRxiv2018

Where the really hard choices are: A general framework to quantify decision difficulty

Life presents us with decisions of varying degrees of difficulty. Many of them are NP-hard, that is, they are computationally intractable. Two important questions arise: which properties of decisions drive extreme computational hardness and what are the effects of these properties on human-decision making? Here, we postulate that we can study the effects of computational complexity on human decision-making by studying the mathematical properties of individual instances of NP-hard problems. We draw on prior work in computational complexity theory, which suggests that computational difficulty can be characterized based on the features of instances of a problem. This study is the first to apply this approach to human decision-making. We measured hardness, first, based on typical-case complexity (TCC), a measure of average complexity of a random ensemble of instances, and, second, based on instance complexity (IC), a measure that captures the hardness of a single instance of a problem, regardless of the ensemble it came from. We tested the relation between these measures and (i) decision quality as well as (ii) time expended in a decision, using two variants of the 0-1 knapsack problem, a canonical and ubiquitous computational problem. We show that participants expended more time on instances with higher complexity but that decision quality was lower in those instances. These results suggest that computational complexity is an inherent property of the instances of a problem, which affect human and other kinds of computers.

animal behavior and cognition↗

bioRxiv2018

Dogs, but not wolves, lose their sensitivity towards novelty with age

Selection on behavioural traits holds a prominent role in the domestication of animals, with reductions in fear behaviour considered to be a key component. Specifically, there is a general assumption that domesticated species express reduced fear and reactivity towards novel stimuli compared to their ancestral species. However, very few studies have explicitly tested this proposed link between domestication and reduced fear responses. Of the limited number of studies experimentally addressing the alterations of fear during domestication, the majority have been done on canids. Previous work in foxes, wolves and dogs has led to the suggestion that decreased expression of fear in domesticated animals is linked to a domestication driven delay in the first onset of fearful behaviour during early ontogeny. Thus, wolves are expected to express exaggerated fearfulness earlier during ontogeny compared to dogs. However, while adult dogs are less fearful towards novelty than adult wolves and wolf-dog hybrids, consensus is lacking on when differences in fear expression arise in wolves and dogs. Here we present the first extended examination of fear development in hand-raised dogs and European grey wolves, using repeated novel object tests from six to 26 weeks of age. Contrary to expectations, we found no evidence in support of an increase in fearfulness in wolves with age or a delayed onset of fear response in dogs compared to wolves. Instead, we found that dogs strongly reduced their fear response in the period between six and 26 weeks of age, resulting in a significant species difference in fear expression towards novelty at 26 weeks. Critically, as wolves did not differ in their fear response towards novelty over time, the detected species difference was caused solely by a progressive reduced fear response in dogs. Our results thereby suggest that species differences in fear of novelty between wolves and dogs are not caused by a domestication driven shift in the first onset of fear response. Instead, we suggest that a loss of sensitivity towards novelty with age in dogs causes the difference in fear expression towards novelty in wolves and dogs.

animal behavior and cognition↗

bioRxiv2018

The evolution of infanticide by females in mammals

In most mammalian species, females regularly interact with kin, and it may thus be difficult to understand the evolution of some aggressive and harmful competitive behaviour among females, such as infanticide. Here, we investigate the evolutionary determinants of infanticide by females by combining a quantitative analysis of the taxonomic distribution of infanticide with a qualitative synthesis of the circumstances of infanticidal attacks in published reports. Our results show that female infanticide is widespread across mammals and varies in relation to social organization and life-history, being more frequent where females breed in groups and have intense bouts of high reproductive output. Specifically, female infanticide occurs where the proximity of conspecific offspring directly threatens the killers reproductive success by limiting access to critical resources for her dependent progeny, including food, shelters, care or a social position. In contrast, infanticide is not immediately modulated by the degree of kinship among females, and females occasionally sacrifice closely related juveniles. Our findings suggest that the potential direct fitness rewards of gaining access to reproductive resources have a stronger influence on the expression of female aggression than the indirect fitness costs of competing against kin.

animal behavior and cognition↗

bioRxiv2018

Hygienic behaviour selection via freeze-killed honey bee brood not associated with chalkbrood resistance in eastern Australia

Hygienic behaviour is a social immune response in honey bees shown to help provide resistance to honey bee pests and diseases. A survey of hygienic behaviour and brood diseases was conducted on 649 colonies in eastern Australia to initiate a selective breeding program targeting disease resistance and provide a level of resistance to Varroa (Varroa destructor Anderson and Trueman and V. jacobsoni Oudemans) mites should they become established in Australia. The test population showed a remarkably high baseline level of hygienic behaviour with 17% of colonies meeting or exceeding breeding selection thresholds. Colonies belonging to a breeding program were 5.8 times more likely to be highly hygienic and colonies headed by queens raised from hygienic queen mothers were 2.2 times more likely. Nectar availability (nectar yielding flowering plants within honey bee forage range) influenced hygienic behaviour expression but was not a significant predictor of level of hygienic behaviour. Surprisingly, hygienic behaviour was not a significant predictor of the presence of infection of the honey bee brood disease chalkbrood (Ascosphaera apis) and was not influential in predicting severity of chalkbrood the infection in surveyed honey bee colonies. This study, along with reports from commercial beekeepers that chalkbrood infection is on the rise, warrants a deeper exploration of the host-pathogen relationship between Apis mellifera and Ascosphaera apis in Australia.

animal behavior and cognition↗

bioRxiv2018

Social integration predicts mitochondrial DNA copy number in rhesus macaques

In many social mammals, social adversity predicts compromised health and reduced fitness. These effects are thought to be driven in part by chronic social stress, but their molecular underpinnings are not well understood. Recent work suggests that chronic stress can affect mitochondrial copy number, heteroplasmy rates, and function. Here, we tested the first two possibilities, for the first time in nonhuman primates. We manipulated dominance rank in captive female rhesus macaques (n=45), where low rank induces chronic social stress, and measured mitochondrial DNA copy number and heteroplasmy in five peripheral blood mononuclear cell types from each study subject. We found no effect of dominance rank on either mtDNA copy number or heteroplasmy rates. However, grooming rates, a measure of affiliative social behavior predicted by high social status, was positively associated with mtDNA copy number in B cells, cytotoxic T cells, and monocytes. Our results suggest that social interactions can influence mtDNA regulation in immune cells. Further, they indicate the importance of considering both affiliative and competitive interactions in investigating this relationship.

animal behavior and cognition↗

bioRxiv2018

Does voluntary wheel running exist in Neotropical wild mammals?

Running wheels are frequently used to improve the welfare of captive animals, increase environmental enrichment, and, by doing so, reduce stereotypic behaviors. It is, however, still debated whether or not wheel running itself is a stereotypy. New evidence emerged when Meijer and Robbers (2014, Proc. Royal Soc. B) reported voluntary wheel running of wild animals in the Netherlands. Since stereotypic behaviors are exclusively attributed to captive animals, the occurrence of wheel running in the wild suggests that this behavior is non-stereotypic. Our study explores that same line of investigation, examining whether wild animals will voluntarily use running wheels in a natural area in Paraguay in comparison to the urban and semi-urban settings in the Netherlands. Of the 1857 small mammal visits we recorded, only two occasions showed evidence of what could be considered as wheel running behavior; over hundredfold fewer than previously reported. The potential reasons for the observed difference in wheel running activity, such as different species pool or seasonality, are discussed. The difference, however, is likely to be due to the much lower probability of Neotropical mammals in a remote natural site encountering man-made objects and experiencing urbanization-related behavioral patterns. Additionally, in the light of our findings, we review the definition of wheel running as a stereotypic behavior.

animal behavior and cognition↗

bioRxiv2018

Spatio-temporal structure and reproductive success in a rook (Corvus frugilegus) colony

We have studied how individual decisions about timing of breeding and nest location affected the reproductive success of rooks by tracing the formation of a rook breeding colony in Hortobagy NP (Hungary), during the breeding season in 1999.\n\nWe have found that birds who built nests earlier also laid eggs earlier and had larger clutch size but had no had more offspring than late nesters. Distance of the nest from the centre or edge of the colony did not affect the reproductive success though rooks generally settled closer to the centre and further from the edge than it can be expected by assuming random distribution. The colony showed high breeding synchrony since date of egg laying varied less than date of nesting but synchrony did not influence the breeding success. Hatchlings survival rate and number of offspring increased with local nest density and rooks clustered their nests more than it can be expected by random settlement. Nest sites of early and late nesters did not differ regarding the distance from the centre or the edge of the colony but late nesters chose nest sites in more densely populated regions.\n\nThe results indicate that individuals may follow different strategies to increase their reproductive success. It is prospectively advantageous to build the nest and lay eggs earlier, in turn, its worth nesting in already more densely nested areas for late beginners. We suggest that a game theoretical approach may be useful if we try to understand the adaptive significance of colonial breeding.

animal behavior and cognition↗

bioRxiv2018

Behavioral Analysis of Substrate Texture Preference in a Leech, Helobdella austinensis

Leeches in the wild are often found on smooth surfaces, such as vegetation, smooth rocks or human artifacts such as bottles and cans, thus exhibiting what appears to be a \"substrate texture preference behavior\". Here, we have reproduced this behavior under controlled circumstances, by allowing leeches to step about freely on a range of silicon carbide sandpaper substrates. To begin to understand the neural mechanisms underlying this texture preference behavior, we have determined relevant parameters of leech behavior both on uniform substrates of varying textures, and in a behavior choice paradigm in which the leech is confronted with a choice between rougher and smoother substrate textures at each step. We tested two non-exclusive mechanisms which could produce substrate texture preference: 1) a Diffusion Trap mechanism, in which a leech is more likely to stop moving on a smooth surface than on a rough one, and; 2) an Anterior Choice mechanism, in which a leech is more likely to attach its front sucker (prerequisite for taking a step) to a smooth surface than to a rough one. We propose that both mechanisms contribute to the texture preference exhibited by leeches.

animal behavior and cognition↗

bioRxiv2018

Truncated power-law distribution of group sizes in antelope

Group size distributions are instrumental in understanding group behaviour in animal populations. We analysed group size data of the blackbuck, Antilope cervicapra, from six different field sites to estimate the group size distribution of this antelope. We show that an exponentially truncated power law (called the polylog distribution in this paper) is the best fitting distribution, against the simple power law and lognormal distributions as other contenders, and the exponential distribution as a control. To show this, we use two likelihood based methods (AICs and likelihood ratios). Finally, we show that polylog distribution parameters can be used to better understand group dynamics, by using them to explore how habitat openness affects group behaviour.

animal behavior and cognition↗

bioRxiv2018

Tracktor: image-based automated tracking of animal movement and behaviour

1. Automated movement tracking is essential for high-throughput quantitative analyses of the behaviour and kinematics of organisms. Automated tracking also improves replicability by avoiding observer biases and allowing reproducible workflows. However, few automated tracking programs exist that are open access, open source, and capable of tracking unmarked organisms in noisy environments.\n\n2. Tracktor is an image-based tracking freeware designed to perform single-object tracking in noisy environments, or multi-object tracking in uniform environments while maintaining individual identities. Tracktor is code-based but requires no coding skills other than the user being able to specify tracking parameters in a designated location, much like in a graphical user interface (GUI). The installation and use of the software is fully detailed in a user manual.\n\n3. Through four examples of common tracking problems, we show that Tracktor is able to track a variety of animals in diverse conditions. The main strengths of Tracktor lie in its ability to track single individuals under noisy conditions (e.g. when the object shape is distorted), its robustness to perturbations (e.g. changes in lighting conditions during the experiment), and its capacity to track multiple individuals while maintaining their identities. Additionally, summary statistics and plots allow measuring and visualizing common metrics used in the analysis of animal movement (e.g. cumulative distance, speed, acceleration, activity, time spent in specific areas, distance to neighbour, etc.).\n\n4. Tracktor is a versatile, reliable, easy-to-use automated tracking software that is compatible with all operating systems and provides many features not available in other existing freeware. Access Tracktor and the complete user manual here: https://github.com/vivekhsridhar/tracktor

animal behavior and cognition↗

bioRxiv2018

Chemical signatures of honey bee group membership develop via a socially-modulated innate process

Large social insect colonies exhibit a remarkable ability for recognizing group members via colony-specific cuticular hydrocarbon (CHC) pheromonal signatures. Previous work suggested that in some ant species colony-specific signatures are generated through a \"gestalt\" mechanism via the passive transfer and homogenization of CHCs across all individual members of the colony. In contrast, we demonstrate that nestmate recognition cues of worker honey bees (Apis mellifera) mature in foragers via a sequence of stereotypic age-dependent quantitative and qualitative chemical transitions, which are driven by intrinsic biosynthetic pathways. Therefore, in contrast to predictions of the \"Gestalt\" model, nestmate recognition cues in honey bee colonies do not represent a passive \"average\" signature that is carried and recognized by all colony members. Instead, specific colony members develop the relevant cues via an innately-determined developmental program that can be modulated by colony-specific social environmental factors.

animal behavior and cognition↗