Biology subjects

Demartsev, V.

Publications and source records attributed to Demartsev, V..

4 recordsLinked to original sources

bioRxiv2024

Spatial position relative to group members affects weight gain in meerkats (Suricata suricatta)

Social animals often face a trade-off between the costs of foraging competition among group members and the benefits of protection from predators offered by group living. The spatial position of an individual in relation to the other group members during foraging can mediate the effects of this trade-off as individuals at the front or edge may have better access to food resources, but also higher predation risk than individuals near the centre of the group. Using meerkats (Suricata suricatta) as a model species, we investigated the effect of individual spatial position within a group on foraging success. We determined the spatial position of individuals in a meerkat group by fitting the animals with high-resolution GPS loggers. As a proxy of foraging success, we used meerkats individual body weight differences between the start and the end of daily data collection over foraging periods (3 hours). We found significant individual differences in meerkats spatial positions within the group. In addition, age-dependent differences in spatial position became obvious, with younger individuals spending more time in the centre of the group and less time in the front. However, younger individuals who spent more time on the side of the group relative to older individuals had higher daily weight gain, indicating more successful foraging. In older individuals, we found that the dominant females tended to spend more time towards the front of the group, but gained less weight in this location, contrary to the predicted association between front edge of the group and better access to food resources. Our results suggest that the relationship between weight gain and spatial position is highly nuanced and likely dependent on more than just trade-offs between foraging success and predation risk. HighlightsO_LISpatial position relative to other group members during foraging was a highly repeatable trait for individual meerkats, though time spent near the front of the group was more strongly influenced by individual traits (age, sex, and social rank) C_LIO_LIYounger meerkats spent less time in the front and more time in the centre of the group relative to older meerkats, but had the highest foraging success towards the sides of the group C_LIO_LIDominant female meerkats spent more time near the front of the group, but had reduced foraging success in this position C_LIO_LIMeerkats may trade-off more than just foraging success and predation risk when making decisions about where to position themselves relative to other group members C_LI

animal behavior and cognition↗

bioRxiv2024

Vocal grooming in meerkats: weakly bonded subordinatescall more in response to dominants

Physical grooming is often used to maintain social bonds in animal groups, but opportunities for grooming each group member may be limited. Vocal exchanges have been proposed as an alternative way to sustain social ties without requiring physical proximity. To explore the link between vocal exchanges and social relationships, we examined the effect of dominance and dyadic bond strength of the interacting partners on the intensity of vocal interaction in meerkats (Suricata suricatta). Focusing on sunning calls, socially facilitated vocalisations produced when meerkats warm themselves in the sun, we conducted experiments where we played sunning calls to individuals and recorded their responses. Overall, subordinate individuals showed an increased call rate when responding to calls from dominants. Tie strength showed a weak trend that differed across dyad types. These results support the notion of meerkat sunning calls having a social regulatory function, possibly as a bonding or appeasing signal, mainly directed to dominant individuals. Our results reflect the dichotomy between the subordinate and dominant individuals and underscore the strategic nature of social relationships within a despotic society. Engaging in continuous reciprocal interactions can signify commitment, promoting tolerance and cooperation. Investing in such interaction with influential dominants could lower the chances of aggression and would fit the vocal grooming functionality of such call exchanges. Further work establishing causal links between vocal interaction patterns and long-term relationship outcomes will be crucial for understanding the scope of vocal grooming as a complement or alternative to physical affiliation across species. LAY SUMMARYMeerkats use more than grooming to manage their social relationships--they also exchange short calls while warming in the sun. Playback of these "sunning calls" to wild meerkats led to increased calling by listeners, particularly when subordinates heard dominants. Females responded somewhat more than males, and social bond strength had a modest influence on calling patterns. Such vocal exchanges may function as "vocal grooming," helping maintain relationships at a distance.

animal behavior and cognition↗

bioRxiv2024

Behavioral sequences across multiple animal species in the wild share common structural features

Animal behavior can be decomposed into a sequence of discrete activity bouts over time. Analyzing the statistical structure of such behavioral sequences can provide insights into the drivers of behavioral decisions. Laboratory studies, predominantly in invertebrates, have suggested that behavioral sequences exhibit multiple timescales and long-range memory, but whether these results can be generalized to other taxa and to animals in natural settings remains unclear. By analyzing accelerometer-inferred predictions of behavioral states in three species of social mammals (meerkats, white-nosed coatis, and spotted hyenas) in the wild, we discovered surprisingly consistent structuring of behavioral sequences across all behavioral states, all individuals, and all study species. Behavioral bouts were characterized by decreasing hazard functions, wherein the longer a behavioral bout had progressed, the less likely it was to end within the next instant. The predictability of an animals future behavioral state as a function of its present state always decreased as a truncated power-law for predictions made farther into the future, with very similar estimates for the power law exponent across all species. Finally, the distributions of bout durations were also heavy-tailed. Why such shared structural principles emerge remains unknown, and we explore multiple plausible explanations, including environmental non-stationarity, behavioral self-reinforcement, and the hierarchical nature of behavior. The existence of highly consistent patterns in behavioral sequences across our study species suggests that these phenomena could be widespread in nature, and points to the existence of fundamental properties of behavioral dynamics that could drive such convergent patterns. Significance statementThe study of animal behavior seeks to understand how and why animals do what they do. This pursuit of general principles governing behavior across species can be approached by first understanding when animals choose to change their behavioral states (e.g., switching from walking to standing, or to running). Using accelerometer-inferred behaviors of three social mammals, we uncover common structural long timescale patterns in their sequences of behavior. We explore two explanations, involving either positive feedbacks or the interaction of several independent time-scales, about how such common patterns arise.

animal behavior and cognition↗

bioRxiv2021

A practical guide for generating unsupervised, spectrogram-based latent space representations of animal vocalizations

The manual detection, analysis, and classification of animal vocalizations in acoustic recordings is laborious and requires expert knowledge. Hence, there is a need for objective, generalizable methods that detect underlying patterns in these data, categorize sounds into distinct groups, and quantify similarities between them. Among all computational methods that have been proposed to accomplish this, neighborhood-based dimensionality reduction of spectrograms to produce a latent-space representation of calls stands out for its conceptual simplicity and effectiveness. Using a dataset of manually annotated meerkat (Suricata suricatta) vocalizations, we demonstrate how this method can be used to obtain meaningful latent space representations that reflect the established taxonomy of call types. We analyze strengths and weaknesses of the proposed approach, give recommendations for its usage and show application examples, such as the classification of ambiguous calls and the detection of mislabeled calls. All analyses are accompanied by example code to help researchers realize the potential of this method for the study of animal vocalizations.

animal behavior and cognition↗