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 Read source abstracts and check manuscript versions; preprints are not peer reviewed.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 235 records · Page 13Linked to original sources

bioRxiv2017

Coupling effect of morphology and mechanical properties contributes to the tribological behaviors of snake scales

It is known that the tribological behaviors of snake skins are contributed by the synergistic action of multiple factors, such as surface morphology and mechanical properties, which has inspired fabrication of scale-like surface textures in recent years. However, the coupling effect and mechanism remain to be elucidated. In this work, the morphology and mechanical properties of the scales from different body sections (leading body half, middle trunk and trailing body half) and positions (dorsal, lateral and ventral) of Boa constrictor and Eryx tataricus have been characterized and compared to investigate the corresponding effects on the tribological behaviors and to probe the possible coupling mechanism. The morphological characterizations of scanning electron microscopy and atomic force microscopy have revealed significant differences between the two species with the roughness of scales from Boa constrictor being larger in general. The mechanical properties measured by nanoindentation have corroboratively demonstrated substantial differences in terms of elastic modulus and hardness. Meanwhile, tribological characterizations of scales in different body positions from the two species also exhibit evident anisotropy. Interestingly, the ventral scales manifest higher friction coefficients but lower surface roughness, together with relatively larger elastic modulus and hardness. A \"double-crossed\" hypothesis has been proposed to explain the observed coupling effect of the morphology and mechanical properties on friction, which may afford valuable insights for the design of materials with desirable tribological performance.

animal behavior and cognition↗

bioRxiv2017

The Potential for Iconicity in Vocalization

The innovation of iconic gestures is essential to establishing the symbolic vocabularies of signed languages, but might iconicity also play a role in the origin of various spoken words? Can people create novel vocalizations that are comprehensible to naive listeners without the use of prior conventions? To test this capacity, we launched a contest in which participants submitted a set of non-linguistic vocalizations for 30 meanings spanning actions, humans, animals, inanimate objects, properties, quantifiers and demonstratives. The winner - who received a monetary prize - was judged by the ability of naive listeners to successfully infer the meanings of the vocalizations. We report the results from the contest, along with a series of experiments and analyses designed to evaluate the vocalizations for: 1) their comprehensibility to naive listeners; 2) the degree to which they resembled their meanings, i.e., were iconic; 3) agreement between producers and listeners in what constitutes an iconic vocalization; and 4) whether iconicity helps naive listeners learn the vocalizations as category labels. The results show that contestants were able to create iconic vocalizations for a wide array of semantic domains, and that these vocalizations were largely comprehensible to naive listeners, as well as easier to learn as category labels. These findings provide a compelling demonstration of the extent to which iconic vocalizations can enable interlocutors to establish understanding through vocalizations in the absence of conventions. This suggests the possibility that, prior to the advent of full-blown spoken languages, people could have used iconic vocalizations to ground a spoken vocabulary with considerable semantic breadth.

animal behavior and cognition↗

bioRxiv2017

Evolution and genetics of precocious burrowing behavior in Peromyscus mice

A central challenge in biology is to understand how innate behaviors evolve between closely related species. One way to elucidate how differences arise is to compare the development of behavior in species with distinct adult traits. Here, we report that Peromyscus polionotus is strikingly precocious with regard to burrowing behavior, but not other behaviors, compared to its sister species P. maniculatus. In P. polionotus, burrows were excavated as early as 17 days of age, while P. maniculatus did not build burrows until 10 days later. Moreover, the well-known differences in burrow architecture between adults of these species--P. polionotus adults excavate long burrows with an escape tunnel, while P. maniculatus dig short, single-tunnel burrows--were intact in juvenile burrowers. To test whether this juvenile behavior is influenced by early-life environment, pups of both species were reciprocally cross-fostered. Fostering did not alter the characteristic burrowing behavior of either species, suggesting these differences are genetic. In backcross F2 hybrids, we show that precocious burrowing and adult tunnel length are genetically correlated, and that a single P. polionotus allele in a genomic region linked to adult tunnel length is predictive of precocious burrow construction. The co-inheritance of developmental and adult traits indicates the same genetic region--either a single gene with pleiotropic effects, or closely linked genes-- acts on distinct aspects of the same behavior across life stages. Such genetic variants likely affect behavioral drive (i.e. motivation) to burrow, and thereby affect both the development and adult expression of burrowing behavior.\n\nHighlightsO_LIJuvenile P. polionotus construct burrows precociously compared to its sister species P. maniculatus\nC_LIO_LICross-fostering does not alter species-specific burrowing behavior\nC_LIO_LIA QTL linked to adult tunnel length predicts developmental onset of burrow construction in hybrids\nC_LIO_LIPleiotropic genetic variant(s) may affect behavioral drive across life stages\nC_LI

animal behavior and cognition↗

bioRxiv2017

Endogenous Oxytocin, Vasopressin and Aggression in Domestic Dogs

Aggressive behavior in dogs poses public health and animal welfare concerns, however the biological mechanisms regulating dog aggression are not well understood. We investigated the relationships between endogenous plasma oxytocin (OT) and vasopressin (AVP) - neuropeptides that have been linked to affiliative and aggressive behavior in other mammalian species - and aggression in domestic dogs. We first validated enzyme-linked immunosorbent assays (ELISAs) for the measurement of free (unbound) and total (free + bound) OT and AVP in dog plasma. In Experiment 1 we evaluated behavioral and neuroendocrine differences between a population of pet dogs with a history of chronic aggression toward conspecifics and a matched control group. Dogs with a history of aggression exhibited more aggressive behavior during simulated encounters with conspecifics, and had lower free, but higher total plasma AVP than matched controls, but there were no group differences for OT. In Experiment 2 we compared OT and AVP concentrations between pet dogs and a population of assistance dogs that have been bred for affiliative and non-aggressive temperaments, and investigated neuroendocrine predictors of individual differences in social behavior within the assistance dog population. Compared to pet dogs, assistance dogs had higher free and total OT, but there were no differences in either measure for AVP. Within the assistance dog population, dogs who behaved more aggressively toward a threatening stranger had higher total AVP than dogs who did not. Collectively these data suggest that endogenous OT and AVP may play critical roles in shaping dog social behavior, including aspects of both affiliation and aggression.

animal behavior and cognition↗

bioRxiv2017

Reflected stochastic differential equation models for constrained animal movement

Movement for many animal species is constrained in space by barriers such as rivers, shore-lines, or impassable cliffs. We develop an approach for modeling animal movement constrained in space by considering a class of constrained stochastic processes, reflected stochastic differential equations. Our approach generalizes existing methods for modeling unconstrained animal movement. We present methods for simulation and inference based on augmenting the constrained movement path with a latent unconstrained path and illustrate this augmentation with a simulation example and an analysis of telemetry data from a Steller sea lion (Eumatopias jubatus) in southeast Alaska.

animal behavior and cognition↗

bioRxiv2017

Born to be asocial: newly-hatched tortoises spontaneously avoid unfamiliar individuals

Individual recognition is important for modulating social interactions but it is not clear to what extent this ability depends on experience gained through repeated interactions with different individuals. In wild tortoises, evidence of social interactions is limited to behaviours performed years after hatching, in the context of mating. To investigate the presence of abilities of individual recognition at the onset of life in tortoises, we used hatchlings of two species (Testudo marginata, Testudo graeca) reared with a single conspecific as unique social experience. When located in a novel environment together with the familiar conspecific, tortoises reached the average distance expected by random trajectories. On the contrary, tortoises tested with an unfamiliar conspecific first explored the mate, then actively kept a distance significantly larger than expected by chance. These results show spontaneous abilities of individual recognition in a non-social species at the onset of life, and active avoidance of unfamiliar conspecifics. We suggest that this predisposed behaviour might be adaptive for young tortoises dispersal.

animal behavior and cognition↗

bioRxiv2017

Scaffolding imagination: A role for medial frontal cortex in the expression of off-task thought

We often think about people, places and events that are outside of our immediate environment. Although prior studies have explored how we can reduce the occurrence of these experiences, the neurocognitive process through which they are produced are less understood. The current study builds on developmental and evolutionary evidence that language helps organise and express our thoughts. Behaviorally, we found the occurrence of task unrelated thought (TUT) in easy situations was associated with thinking in words. Using experience sampling data, in combination with online measures of neural function, we established that activity in a region of anterior cingulate cortex / medial-prefrontal cortex (mPFC) tracked with changes in the expression of TUT. This region is at the intersection of two mPFC clusters identified through their association with variation in aspects of spontaneous thought: thinking in words (dorsal) and mental time travel (ventral). Finally, using meta-analytic decoding we confirmed the dorsal/ventral distinction within mPFC corresponding to a functional difference between domains linked to language and meaning and those linked to memory and scene construction. This evidence suggests a role for mPFC in the expression of TUT that may emerge from interactions with distributed neural signals reflecting processes such as language and memory.

animal behavior and cognition↗

bioRxiv2017

Welfare of zebra finches used in research

Over the past 50 years, songbirds have become a valuable model organism for scientists studying vocal communication from its behavioral, hormonal, neuronal, and genetic perspectives. Many advances in our understanding of vocal learning result from research using the zebra finch, a close-ended vocal learner. We review some of the manipulations used in zebra finch research, such as isolate housing, transient/irreversible impairment of hearing/vocal organs, implantation of small devices for chronic electrophysiology, head fixation for imaging, aversive song conditioning using sound playback, and mounting of miniature backpacks for behavioral monitoring. We highlight the use of these manipulations in scientific research, and estimate their impact on animal welfare, based on the literature and on data from our past and ongoing work. The assessment of harm-benefits tradeoffs is a legal prerequisite for animal research in Switzerland. We conclude that a diverse set of known stressors reliably lead to suppressed singing rate, and that by contraposition, increased singing rate may be a useful indicator of welfare. We hope that our study can contribute to answering some of the most burning questions about zebra finch welfare in research on vocal behaviors.

animal behavior and cognition↗

bioRxiv2017

An integral role for timing in interception

Timing is critical for myriad behaviors in dynamic environments. For example, to intercept an object, the brain must compute a reliable estimate of time-to-contact (TTC). Prior work suggests that humans compute TTC using kinematic information such as distance and speed without explicitly relying on temporal cues, just as one would do in a physics classroom using kinematic equations. Considering the inherent uncertainty associated with estimates of speed and distance and the ability of human brain to combine different sources of information, we asked whether humans additionally rely on temporal cues. We found that humans actively integrate speed information with both explicit and implicit timing cues. Analysis of behavior in relation to a Bayesian model revealed that the additional temporal information helps subjects optimize their performance in the presence of measurement uncertainty. These findings suggest that brains timing mechanisms are actively engaged while interacting with dynamic stimuli.

animal behavior and cognition↗

bioRxiv2017

General sexual desire, but not desire for uncommitted sexual relationships, tracks changes in women’s hormonal status

Several recent longitudinal studies have investigated the hormonal correlates of both young adult womens general sexual desire and, more specifically, their desire for uncommitted sexual relationships. Findings across these studies have been mixed, potentially because each study tested only small samples of women (Ns = 43, 33, and 14). Here we report results from a much larger (N = 375) longitudinal study of hormonal correlates of young adult womens general sexual desire and their desire for uncommitted sexual relationships. Our analyses suggest that within-woman changes in general sexual desire are negatively related to progesterone, but are not related to testosterone or cortisol. We observed some positive relationships for estradiol, but these were generally only significant for solitary sexual desire. By contrast with our results for general sexual desire, analyses showed no evidence that changes in womens desire for uncommitted sexual relationships are related to their hormonal status. Together, these results suggest that changes in hormonal status contribute to changes in womens general sexual desire, but do not influence womens desire for uncommitted sexual relationships.

animal behavior and cognition↗

bioRxiv2017

Hormonal correlates of pathogen disgust: Testing the Compensatory Prophylaxis Hypothesis

Raised progesterone during the menstrual cycle is associated with suppressed physiological immune responses, reducing the probability that the immune system will compromise the blastocysts development. The Compensatory Prophylaxis Hypothesis proposes that this progesterone-linked immunosuppression triggers increased disgust responses to pathogen cues, compensating for the reduction in physiological immune responses by minimizing contact with pathogens. Although a popular and influential hypothesis, there is no direct, within-woman evidence for correlated changes in progesterone and pathogen disgust. To address this issue, we used a longitudinal design to test for correlated changes in salivary progesterone and pathogen disgust (measured using the pathogen disgust subscale of the Three Domain Disgust Scale) in a large sample of women (N=375). Our analyses showed no evidence that pathogen disgust tracked changes in progesterone, estradiol, testosterone, or cortisol. Thus, our results provide no support for the Compensatory Prophylaxis Hypothesis of variation in pathogen disgust.

animal behavior and cognition↗

bioRxiv2017

Birds have swing: Multifractal analysis reveals expressive rhythm in birdsong.

Music is thought to engage its listeners by driving feelings of surprise, tension, and relief through a dynamic mixture of predictable and unpredictable patterns, a property summarized here as \"expressiveness\". Birdsong shares with music the goal to attract and hold its listeners attention and might make use of similar strategies to achieve this goal. We here tested a songbirds rhythm, as represented by the amplitude envelope (containing information on note timing, duration, and intensity), for expressiveness. We used multifractal analysis which is designed to detect in a signal dynamic fluctuations between predictable and unpredictable states on multiple timescales (e.g. notes, subphrases, songs). Results show that the songs' amplitude envelope is strongly multifractal, indicating rhythm is patterned by fluctuations between predictable and unpredictable patterns. Moreover, comparing original songs with re-synthesized songs that lack all subtle deviations from the \"standard\" note envelopes, we find that deviations in note intensity and duration significantly contribute to the rhythms multifractality. This suggests that birds render their songs more expressive by subtly modifying note timing patterns, similar to musical operations like accelerando or ritardando. Our findings bear consequences for neuronal models of vocal sequence generation in birds, as they require non-local rules to generate rhythm.

animal behavior and cognition↗

bioRxiv2017

Semantic Networks Generated from Early Linguistic Input

Semantic networks generated from different word corpora show common structural characteristics, including high degrees of clustering, short average path lengths, and scale free degree distributions. Previous research has disagreed about whether these features emerge from internally or externally driven properties (i.e. words already in the lexicon vs. regularities in the external world), mapping onto preferential attachment and preferential acquisition accounts, respectively (Steyvers & Tenenbaum, 2005; Hills, Maouene, Maouene, Sheya, & Smith, 2009). Such accounts suggest that inherent semantic structure shapes new lexical growth. Here we extend previous work by creating semantic networks using the SEEDLingS corpus, a newly collected corpus of linguistic input to infants. Using a recently developed LSA-like approach (GLoVe vectors), we confirm the presence of previously reported structural characteristics, but only in certain ranges of semantic similarity space. Our results confirm the robustness of certain aspects of network organization, and provide novel evidence in support of preferential acquisition accounts.

animal behavior and cognition↗

bioRxiv2017

Facultative adjustment of paternal care in the face of female infidelity in dunnocks

A much-debated issue is whether or not males should reduce parental care when they lose paternity (i.e. the certainty of paternity hypothesis). While there is general support for this relationship across species, within-population evidence is still contentious. Among the main reasons behind such problem is the confusion discerning between-from within-individual patterns. Here, we tested this hypothesis empirically by investigating the parental care of male dunnocks (Prunella modularis) in relation to paternity. We used a thorough dataset of observations in a wild population, genetic parentage, and a within-subject centring statistical approach to disentangle paternal care adjustment within-male and between males. We found support for the certainty of paternity hypothesis, as there was evidence for within-male adjustment in paternal care when socially monogamous males lost paternity to extra-pair sires. There was little evidence of a between-male effect overall. Our findings show that monogamous males adjust paternal care when paired to the same female partner. We also show that - in monogamous broods - the proportion of provisioning visits made by males yields fitness benefits in terms of fledging success. Our results suggest that socially monogamous females that engage in extra-pair behaviour may suffer fitness costs, as their partners reduction in paternal care can negatively affect fledging success.

animal behavior and cognition↗

bioRxiv2017

Do Sigmoidal Acquisition Curves Indicate Conformity?

The potential for behaviours to spread via cultural transmission has profound implications for our understanding of social dynamics and evolution. Several studies have provided empirical evidence that local traditions can be maintained in animal populations via conformist learning (i.e. copying the majority). A conformist bias can be characterized by a sigmoidal relationship between a behaviors prevalence in the population and an individuals propensity to adopt that behavior. For this reason, the presence of conformist learning in a population is often inferred from a sigmoidal acquisition curve in which the overall rate of adoption for the behavior is taken as the dependent variable. However, the validity of sigmoidal acquisition curves as evidence for conformist learning has recently been challenged by models suggesting that such curves can arise via alternative learning rules that do not involve conformity. We review these models, and find that the proposed alternative learning mechanisms either rely on faulty or unrealistic assumptions, or apply only in very specific cases. We therefore recommend that sigmoidal acquisition curves continue to be taken as evidence for conformist learning. Our paper also highlights the importance of understanding the generative processes of a model, rather than only focusing solely on the patterns produced. By studying these processes, our analysis suggests that current practices by empiricists have provided robust evidence for conformist transmission in both humans and non-human animals.

animal behavior and cognition↗

bioRxiv2017

The quality of social relationships affects male health in a complex bird society

In group living animals, behavioural interactions with conspecifics strongly modulate an individuals physiological stress response. Stable social relationships may reduce an individuals stress response, which in turn can affect the immune system and health. Ultimately, positive health effects of stable social bonds may contribute to maintain group living. We investigated whether, in cooperatively breeding carrion crows (Corvus corone), the quality of social relationships correlates with coccidian oocyst and nematode eggs excretion. We repeatably collected behavioural data on dyadic social interactions and individual droppings to quantify parasite eggs and oocysts from 36 individuals in a captive population of carrion crows in northern Spain. Individuals with strong social bonds, living with more relatives and in larger groups excreted a significantly smaller proportion of droppings containing coccidian oocysts. The probability to excrete droppings containing nematode eggs was not affected by social factors. The relationship between social interactions and coccidian oocyst excretion is consistent with the idea that high quality social relationships can positively affects individuals health, setting the stage for the evolution of stable social living.

animal behavior and cognition↗

bioRxiv2017

Orb-web spider color polymorphism through the eyes of multiple prey and predators

The sensory drive theory predicts that signals, sensory systems, and signaling behavior should coevolve. Variation in the sensory systems of prey and predators may explain the diversity of color signals, such as color polymorphism. The spider Gasteracantha cancriformis (Araneidae) possesses several conspicuous color morphs. The aim of the present study was to assess whether the color polymorphism of G. cancriformis may be maintained by pressure from multiple signal receivers, such as prey and predators with distinct color vision systems. Although, the multiple receivers world is a more realistic scenario, it has received little attention. In orb-web spiders, the prey attraction hypothesis states that conspicuous colors are prey lures that increase spider foraging success via flower mimicry. However, in highly defended species, conspicuous colors could also be a warning signal to predators. We used color vision modelling to estimate chromatic and achromatic contrast of G. cancriformis morphs as perceived by potential prey and predator taxa. Our results revealed that individual prey and predator taxa perceive the conspicuousness of morphs differently. For instance, the red morph is perceived as quite conspicuous to lepidopteran prey and avian predators, but not by other insects. Therefore, the multiple prey and predator hypotheses may explain the evolution of color polymorphism in G. cancriformis. However, flower mimicry hypothesis was weakly corroborated. Other parameters that are not evaluated by color vision models, such as distance, shape, angle, and pattern geometry could also affect the perception of color morphs by both prey and predators and thereby influence morph survival.

animal behavior and cognition↗

bioRxiv2017

Bayesian inference and simulation approaches improve the assessment of Elo-scores in the analysis of social behaviour

O_LIThe construction of rank hierarchies based on agonistic interactions between two individuals (\"dyads\") is an important component in the characterization of the social structure of groups. To this end, winner-loser matrices are typically created, which collapse the outcome of dyadic interactions over time, resulting in the loss of all information contained in the temporal domain. Methods that track changes in the outcome of dyadic interactions (such as \"Elo-scores\") are receiving increasing interest. Critically, individual scores are not just based on the succession of wins and losses, but depend on the values of starting scores and an update (\"tax\") coefficient. Recent studies improved existing methods by introducing a point estimation of these auxiliary parameters on the basis of a maximum likelihood (ML) approach. For a sound assessment of the rank hierarchies generated this way, we argue that measures of uncertainty of the estimates, as well as a quantification of the robustness of the methods, are also needed.\nC_LIO_LIWe introduce a Bayesian inference (BI) approach using partial pooling\", which rests on the assumption that all starting scores are samples from the same distribution. We compare the outcome of the ML approach to that of the BI approach using real-world data. In addition, we simulate different scenarios to explore in which way the Elo-score responds to social events (such as rank changes), and low numbers of observations.\nC_LIO_LIEstimates of the starting scores based on partial pooling\" are more robust than those based on ML, also in scenarios where some individuals have only few observations. Our simulations show that assumed rank differences may fall well within the uncertain\" range, and that low sampling density, unbalanced designs, and coalitionary leaps involving several individuals within the hierarchy may yield unreliable results.\nC_LIO_LIOur results support the view that Elo rating can be a powerful tool in the analysis of social behaviour, when the data meet certain criteria. Assessing the uncertainty greatly aids in the interpretation of results. We advocate running simulation approaches to test how well Elo scores reflect the (simulated) true structure and how sensitive the score is to true changes in the hierarchy.\nC_LI

animal behavior and cognition↗