Biology subjects

Martin, J. G. A.

Publications and source records attributed to Martin, J. G. A..

5 recordsLinked to original sources

bioRxiv2026

Deviations from an individual's average sociality have fitness consequences

Social relationships are consequential and affect survival, longevity and reproductive success in many species. Prior studies have successfully identified the fitness consequences of variation in sociality relative to other individuals. However, we have yet to quantify the fitness consequences of social variation within an individual over time. By using a within-individual centering approach, we can identify the consequences of deviations from an individuals average sociality. This approach has not been applied to the study of animal sociality. We used 20 years of data from a population of yellow-bellied marmots (Marmota flaviventer) to understand the fitness consequences of an individuals average affiliative social network position over their lifetime, and of individuals annual deviations from their average social position. We found that an individuals deviation from its average sociality was very strongly associated with both winter and summer survival. Deviations from some average measures of sociality were also associated with the likelihood of reproducing, but not in a consistent direction. Lifetime average social network positions had limited associations with survival and reproduction. Interestingly, litter size results varied between males to females; neither lifetime averages of social network traits nor deviations from these averages were associated with litter size in females, but deviations in sociality were associated with larger numbers of weaned offspring in males. Future studies of the consequences of social relationships may benefit from the use of an individual-centering approach, and further work is required to understand the environmental and social drivers of this intra-individual adaptive plasticity. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=184 SRC="FIGDIR/small/728517v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@9203bborg.highwire.dtl.DTLVardef@33155dorg.highwire.dtl.DTLVardef@1bfac92org.highwire.dtl.DTLVardef@daab44_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LILifetime averages of social network traits are not associated with fitness C_LIO_LIAnnual deviations from lifetime average sociality improves survival and reproduction C_LIO_LIIntra-individual behavioral plasticity may be an understudied fitness driver C_LIO_LIWithin-individual centering is a useful approach for the study of animal behavior C_LI

animal behavior and cognition↗

bioRxiv2024

Prey movement shapes the acquisition of predator expertise in a virtual bi-trophic system

The acquisition of expertise is crucial for predators to be successful hunters. To achieve this, predators must hone their skills and gain knowledge through repeated and extensive practice. On the other hand, prey may hinder the acquisition of predator expertise by employing antipredator tactics to evade detection and pursuit. However, empirical evidence on how predators acquire expertise through repeated encounters with their prey remains limited, largely due to the challenges of monitoring direct interactions in the wild. Here, we use a virtual predator-prey system (the game Dead by Daylight) to investigate how experience shapes individual and population hunting success in human predators across repeated interactions with their prey. We show that predators optimized prey consumption as they gained experience, indicating that they acquired expertise through extensive practice. At the population-level, we found that faster prey impaired the acquisition of expertise by reducing hunting success. Prey speed was also an important mediator of this relationship at the individual level, driving differences among predators in the acquisition of expertise. Our study outlines how prey antipredator behaviour can mediate the acquisition of expertise in predator populations.

ecology↗

bioRxiv2022

The effect of heterospecific and conspecific competition on inter-individual differences in tungara frog tadpole (Engystomops pustulosus) behaviour

Repeated social interactions with conspecifics and/or heterospecifics during early development may drive the differentiation of behaviour among individuals. This behavioural differentiation may occur through individuals behaving more different from each other on average and/or individuals behaving more consistently. Competition is a major form of social interaction and its impacts can depend on whether interactions occur between conspecifics or heterospecifics and the directionality of a response could be specific to different behavioural traits. To test this, we reared tungara frog tadpoles (Engystomops pustulosus) either in isolation, with a conspecific tadpole or with an aggressive heterospecific tadpole, the whistling frog tadpole, Leptodactylus fuscus. In each treatment, we measured the body size, activity, exploration and risk taking in the presence of a predator in focal E. pustulosus tadpoles six times during development. We used univariate and multivariate hierarchical mixed effect models to investigate the effect of treatment on mean behaviour and on among individual variance between and within individuals across behavioural traits. There was a strong effect of competition on behaviour, with different population and individual level responses across social treatments. Within their home tank, individuals were more consistent in their movements under conspecific competition but heterospecific competition caused more variance in the average movement among individuals. Behavioural responses were also trait specific as conspecific competition caused greater variability in movements among individuals in a novel environment. The results highlight that the impact of competition on inter-individual differences in behaviour is dependent on competitor species identity and is trait specific.

animal behavior and cognition↗

bioRxiv2021

Hibernation slows epigenetic aging in yellow-bellied marmots

Species that hibernate live longer than would be expected based solely on their body size. Hibernation is characterized by long periods of metabolic suppression (torpor) interspersed by short periods of increased metabolism (arousal). The torpor-arousal cycles occur multiple times during hibernation, and it has been suggested that processes controlling the transition between torpor and arousal states cause aging suppression. Metabolic rate is also a known correlate of longevity, we thus proposed the hibernation-aging hypothesis whereby aging is suspended during hibernation. We tested this hypothesis in a well-studied population of yellow-bellied marmots (Marmota flaviventer), which spend 7-8 months per year hibernating. We used two approaches to estimate epigenetic age: the epigenetic clock and the epigenetic pacemaker. Variation in epigenetic age of 149 samples collected throughout the life of 73 females were modeled using generalized additive mixed models (GAMM), where season (cyclic cubic spline) and chronological age (cubic spline) were fixed effects. As expected, the GAMM using epigenetic ages calculated from the epigenetic pacemaker was better able to detect nonlinear patterns in epigenetic age change over time. We observed a logarithmic curve of epigenetic age with time, where the epigenetic age increased at a higher rate until females reached sexual maturity (2-years old). With respect to circannual patterns, the epigenetic age increased during the summer and essentially stalled during the winter. Our enrichment analysis of age-related CpG sites revealed pathways related to development and cell differentiation, while the season-related CpGs enriched pathways related to central carbon metabolism, immune system, and circadian clock. Taken together, our results are consistent with the hibernation-aging hypothesis and may explain the enhanced longevity in hibernators.

evolutionary biology↗

bioRxiv2021

The effects of maternal social connectivity and integration on offspring survival in a marmot

In social species, maternal social relationships, in addition to direct care, impact offspring survival but much of what we know about these effects comes from studies of obligately social and cooperatively breeding species. Yellow-bellied marmots (Marmota flaviventer) are a facultatively social species whose social groups vary in composition, size, and cohesiveness. This natural variation in sociality and cooperative breeding behavior makes yellow-bellied marmots an ideal species within which to study the effects of maternal affiliative and agonistic social behavior on offspring. We used social network analysis to investigate the relationship between maternal social connectivity and integration on offspring summer and yearly survival, with the hypothesis that offspring with more affiliative mothers are more likely to survive than the offspring of more agonistic mothers. However, we found the inverse to be true: pups born to mothers who received more affiliative interactions were less likely to survive while the offspring of mothers who were more highly integrated into agonistic networks had enhanced survival. Overall, maternal social network measures were positively and negatively correlated with offspring survival, indicating that pups are influenced by their mothers social world, often in contradictory ways. Relative predation risk and colony location also mediated the effects of social relationships on pup survival. This study contributes to a small but growing body of work that demonstrates that specific attributes of sociality have specific consequences and that by adopting an attribute-focused view of sociality we are better able to understand how environmental conditions mediate the costs and benefits of sociality. Lay SummaryMaternal social relationships can impact offspring survival but much of what we know about these effects comes from studies of obligately social species. In faculatively social yellow-bellied marmots we found that pups born to mothers who received more affiliative interactions were less likely to survive while the offspring of mothers who were more highly integrated into agonistic networks had enhanced survival. Overall, pups are influenced by their mothers social world, often in contradictory ways.

animal behavior and cognition↗