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Crofoot, M. C.

Publications and source records attributed to Crofoot, M. C..

16 recordsLinked to original sources

Kinship, acoustic signaling, and socio-spatial structure shape shared decisions and social influence in white-nosed coatis

When individual preferences for collective outcomes diverge, cohesive animal groups often coalesce on the majority opinion. However, majority-based decision rules may be counterbalanced by other factors, particularly in heterogeneous groups with differentiated social relationships, and these factors could produce inequality in social influence. We used multi-sensor tracking collars to collect detailed and simultaneous data on the movements and vocalizations of almost all members of three wild white-nosed coati (Nasua narica) groups, and analyzed 2,401 individual decisions between conflicting travel directions. Decision-making was shared: individuals favored directions that had majority support, and we found evidence that they used acoustic signals and movement cues to infer majority support. Individuals were also more likely to choose directions favored by closer kin and by groupmates in more frontward spatial positions. Although decisions were shared, influence was not equally distributed across individuals. During directional conflicts, individuals who were more likely to form majorities or who were advantaged by frontward spatial positions had higher influence over travel direction. By explicitly linking decisions by individual followers to emergent patterns of influence among potential leaders, our results suggest that influence is a complex product of higher-order interactions that are likely dependent on group demography and socio-spatial structure.

animal behavior and cognition↗

The vocal repertoire of white-nosed coatis: structural features, temporal dynamics, and social variations

For many group living species, vocal signals are a vital form of communication needed to coordinate social behaviours. Investigating these processes first requires a detailed description of the species vocal repertoire. White-nosed coatis (Nasua narica), which forage and move together in forest habitats, are thought to rely on vocalisations to coordinate movements and maintain group cohesion. However, quantitative studies of their vocal repertoire are lacking. We examined the vocal repertoire of white-nosed coatis from wild populations in Panama and Arizona, USA, to gain a more comprehensive view of their calling behaviours. By combining traditional acoustic analyses with an unsupervised approach based on spectrogram structure, we characterised the diversity of calls in this species and described the temporal and structural features of their vocalisations. We identified 19 call types, with some of these calls emitted in multi-syllable call sequences or in fast succession. We found variability in call rates among group members, which may be driven by differences in social status within the group. In addition, our results indicate that white-nosed coatis likely have individually-recognisable vocalisations. This study provides a foundational description of the white-nosed coati vocal repertoire, laying the groundwork for future research on vocal communication in this species.

animal behavior and cognition↗

Maternal ranging strategies facilitate offspring social play at energetic cost in the most solitary ape

In most vertebrates, social play among peers is considered essential for behavioral development. Yet in solitary species bearing single offspring, opportunities for social play are inherently scarce. Whether mothers of such species actively facilitate play opportunities for their offspring, and at what cost, remains unknown. We used 15 years of behavioral and movement data ([~]30,000 observation hours) from 31 wild Bornean orangutan (Pongo pygmaeus wurmbii) mother-offspring pairs to test whether mothers adjust ranging behavior to increase their offsprings access to play with neighboring peers. Neighboring mothers with similarly aged offspring showed disproportionately high annual overlap in space use, independent of their relatedness or fruit availability. They intensified use of shared areas within existing range boundaries rather than shifting or expanding their ranges, indicating a fine-scaled ranging strategy. Mothers also incurred energetic costs; on days their offspring played with peers, mothers traveled farther and spent less time feeding. Travel distances were also elevated on the days before and after play, with mothers orienting movement toward play partners core areas before play and back toward their own core areas after play. This suggests these encounters are planned and actively pursued over multiple days rather than arising by chance. These findings reveal that orangutan mothers incorporate their infants social needs into daily ranging decisions, at a cost to their own energy budgets. This points toward an underappreciated form of maternal investment and illustrates how the social requirements of development can be met even near the solitary extreme of animal social organization.

ecology↗

Vocal coordination and conflict avoidance shape fission-fusion dynamics in white-nosed coatis

Many social animals exhibit fission-fusion dynamics, where group members split into subgroups and come back together. Studying these dynamics can reveal how individuals weigh the costs and benefits of sociality. Most studies infer the drivers of fission-fusion dynamics by examining subgroup association patterns, yet different underlying processes can produce similar patterns. Here we take a fundamentally different approach by focusing on subgrouping events themselves, where decision-making plays out in real time. Using multi-sensor tracking collars, we collected simultaneous movement and vocalisation data from all group members within two wild white-nosed coati groups. We developed analytical tools to extract and characterise fission and fusion events, thus establishing a framework for quantifying the spatiotemporal dynamics of these events and the use of vocalisations before, during, and after them. We found that fissions typically occurred when groups were initially stationary, indicating that splitting does not result from loss of coordination while moving.Subgrouping was associated with reduced aggression, yet aggressive vocalisations did not precede splits, supporting the hypothesis that subgrouping is a pre-emptive mechanism to manage within-group conflict. Contact calls in moving subgroups increased before fissions and fusions, indicating that vocal communication is key to the coordination of these collective movement decisions.

animal behavior and cognition↗

Between-group competitive advantage offsets foraging costs for bigger groups in harsher seasons

Larger animal groups are widely understood to require more space and expend more energy to mitigate the foraging costs of within-group competition. Yet between-group interactions and shifting resource distributions can obscure links between group size and behavior, making responses to demographic change difficult to predict. Using 33 years of observational data from 12 neighboring white-faced capuchin (Cebus imitator) groups in Costa Rica, combined with remotely sensed environmental data, we show that within- and between-group competition jointly shape space use, with their relative importance shifting with seasonal and interannual climate cycles. Larger groups compensated for reduced per-capita foraging efficiency by expanding into less-exploited areas over longer timescales rather than increasing daily travel. Notably, this expansion disproportionately encroached on smaller neighboring groups. In the dry season, resource confinement to riparian zones increased intergroup encounters and reduced overlap, with larger groups occupying the highest-quality areas. Climatic extremes linked to El Nino and La Nina exacerbated within-group foraging costs for large groups, whereas intermediate anomalies relaxed these constraints and amplified the benefits of between-group competitive ability. Our findings show that environmental variation shifts the trade-offs of within- and between-group competition, shaping how group-living animals adjust to changing social and ecological conditions.

ecology↗

Development and social dynamics of stone tool use in white-faced capuchin monkeys

Percussive tool use for extractive foraging allows animals to access otherwise inaccessible resources and forage more efficiently, with potentially important implications for their fitness. The development of tool use proficiency has been well-documented in nut-cracking chimpanzees and robust capuchins, and in shellfish-cracking long-tailed macaques, where mothers and proficient tool users are the most important models for social learning. However, little is known about how tool use develops in populations where opportunities for social learning are scarce. White-faced capuchins (Cebus capucinus imitator) on Jicaron Island, Panama, provide a unique case to consider this question: stone tool use is entirely male-biased, meaning juveniles cannot learn from their mothers, and reduced group cohesion further limits social learning opportunities. Here, we investigate the acquisition and development of stone tool proficiency in this population using a year-long dataset from camera traps placed at two experimental anvils. We assess differences in proficiency between age classes, examine the development of tool use proficiency over time, and explore patterns of social attention during tool use. We show that juvenile capuchins are less proficient than subadults and adults, but their proficiency remains stable over the course of one year, suggesting that skill development may require prolonged practice or physical maturation. In contrast to other primates, social learning opportunities on Jicaron appear limited and scrounging is rare, yet when social attention occurs, we find robust patterns. Social attention to tool use mostly comes from juveniles too young to use tools themselves, who observe proficient subadults that tolerate scrounging. Our results contribute to the understanding of how complex tool use behaviours are acquired and maintained in primates. They highlight that even when tool use is largely solitary, directed social attention and social tolerance play an important role in the development of tool use proficiency. HighlightsO_LIJuvenile white-faced capuchins are less proficient tool users than (sub)adults C_LIO_LIDevelopment of capuchins tool use proficiency is a slow process C_LIO_LISocial learning opportunities on Jicaron island are limited and social attention rare C_LIO_LIAttention was selective, juveniles to proficient sub(adults) who tolerated scrounging C_LIO_LINon-tool-using juveniles paid most attention, so likely important for acquisition C_LI

animal behavior and cognition↗

Magellanic penguins balance navigation with foraging opportunities in complex current regimes

Animals navigating in fluid environments often face lateral forces from wind or water currents that challenge travel efficiency and route accuracy. We investigated how 27 Magellanic penguins (Spheniscus magellanicus) adapt their navigation strategies to return to their colony amid regional tidal ocean currents. Using GPS-enhanced dead-reckoning loggers and high-resolution ocean current data, we reconstructed penguin travel vectors during foraging trips to assess their responses to variable currents during their colony-bound movements. By integrating estimates of energy costs and prey pursuits, we found that birds balanced direct navigation with current-driven drift: in calm currents, they maintained precise line-of-sight headings to their colony. In stronger currents, they aligned their return with lateral flows, which increased travel distance, but at minimal energy costs, and provided them with increased foraging opportunities. Since the lateral tidal currents always reversed direction over the course of return paths, the penguins return paths were consistently S-shaped but still resulted in the birds returning efficiently to their colonies. These findings suggest that Magellanic penguins can sense current drift and use it to optimize energy expenditure by maintaining overall directional accuracy while capitalizing on foraging opportunities.

animal behavior and cognition↗

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↗

Whole group tracking reveals that relatedness drives consistent subgrouping patterns in white-nosed coatis

The formation of subgroups can allow group-living animals flexibility to balance the costs and benefits of sociality over time. Subgrouping dynamics emerge from individual decisions about whether and with whom to maintain cohesion, with these decisions potentially influenced by ecological, physiological, and social factors. We GPS-tracked the movements of nearly all members of three wild white-nosed coati (Nasua narica) social groups that differed in their demographic profiles to better understand how these highly social, frugivorous carnivores weight the relative importance of these different factors in their grouping decisions. Quantifying group movements and subgrouping patterns, we found that two of the three groups we tracked exhibited fission-fusion behaviours, with groups splitting into subgroups that persisted over varying timespans from minutes to days. In contrast, the third group remained together across the entire observation period. When groups split, they did not do so randomly; instead, individuals tended to form subgroups with the same individuals consistently over time. Assessing the drivers of subgrouping patterns revealed that subgroup membership was associated with genetic relatedness, but not physiological similarity as quantified by age and sex homophily. Our results demonstrate great variation in subgrouping patterns within a single species, while also highlighting a consistent role of relatedness in driving social preferences when subgroups form.

animal behavior and cognition↗

Male-biased stone tool use by wild white-faced capuchins (Cebus capucinus imitator)

Tool-using primates often show sex differences in both the frequency and efficiency of tool use. In species with sex-biased dispersal, such within-group variation likely shapes patterns of cultural transmission of tool-use traditions between groups. On the Panamanian islands of Jicaron and Coiba, a population of white-faced capuchins (Cebus capucinus imitator)--some of which engage in habitual stone tool use--provide an opportunity to test hypotheses about why such sex-biases arise. On Jicaron, we have only observed males engaging in stone tool use, whereas on Coiba, both sexes are known to use tools. Using 5 years of camera trap data, we show that this variation reflects a true sex difference in tool use rather than a sampling artefact, and then test hypotheses about the factors driving this pattern. Differences in physical ability or risk-aversion, and competition over access to anvils do not account for the sex-differences in tool-use we observe. Our data show that females are physically capable of stone tool use: females on Coiba and juveniles on Jicaron as small and smaller than adult females regularly engage in tool use. Females also have ample opportunity to use tools: the sexes are equally terrestrial, and competition over anvils is low. Finally, females rarely scrounge on left-over food items either during or after tool-using events, suggesting they are not being provisioned by males. Although it remains unclear why white-faced capuchin females on Jicaron do not use stone-tools, our results illustrate that such sex biases in socially learned behaviors can arise even in the absence of obvious physical, environmental and social constraints. This suggests that a much more nuanced understanding of the differences in social structure, diet and dispersal patterns are needed to explain why sex-biases in tool use arise in some populations but not in others.

animal behavior and cognition↗

Coupling of Coastal Activity with Tidal Cycles is Stronger in Tool-using Capuchins (Cebus capucinus imitator)

Terrestrial mammals exploiting coastal resources must cope with the challenge that resource availability and accessibility fluctuate with tidal cycles. Tool use can improve foraging efficiency and provide access to structurally protected resources that are otherwise unavailable (e.g., mollusks and fruits). To understand how variable accessibility of valuable resources shapes behavioral patterns, and whether tool use aids in the efficient exploitation of intertidal resources, we compared the relationship between tidal cycles and activity patterns of tool-using vs. non-tool-using groups of white-faced capuchin monkeys on Jicaron Island in Coiba National Park, Panama. Although only a single group of capuchins on Jicaron uses tools, all coastal groups forage on intertidal resources. Using data from >3 years of camera trapping at varying distances from the coast, we found that capuchins on Jicaron showed increased coastal activity during specific parts of the tidal cycle, and that this relationship differed between tool-using and non-tool-using groups, as well as between seasons. Activity patterns of tool-using capuchins were more strongly and consistently tied to tidal cycles compared to non-tool-users, indicating that tool use might allow for more efficient exploitation of tidal resources. Our findings highlight the potential of tool use to aid niche expansion.

animal behavior and cognition↗

Ecological and social pressures interfere with homeostatic sleep regulation in the wild

Sleep is fundamental to the health and fitness of all animals. The physiological importance of sleep is underscored by the central role of homeostasis in determining sleep investment - following periods of sleep deprivation, individuals experience longer and more intense sleep bouts. Yet, most studies of sleep have been conducted in highly controlled settings, disconnected from the ecological and social context that may exert pressures on sleep patterns in conflict with homeostatic regulation. Using tri-axial accelerometry and GPS to track the sleep patterns of a group of wild baboons (Papio anubis) at multiple temporal and spatial scales, we found that ecological and social pressures indeed interfere with homeostatic sleep regulation. Baboons sacrificed time spent sleeping when in less familiar locations and when sleeping in proximity to more group-mates, regardless of how much they had slept the prior night or how much they had physically exerted themselves the preceding day. Moreover, we found that the collective dynamics characteristic of social animal groups persist into the sleep period, as baboons exhibited synchronized patterns of waking throughout the night, particularly with nearby group-mates. Thus, for animals whose fitness depends critically on avoiding predation and developing social relationships, maintaining sleep homeostasis may be only secondary to remaining vigilant when sleeping in risky habitats and interacting with group-mates during the night. Our results highlight the importance of studying sleep in ecologically relevant contexts, where the adaptive function of sleep patterns directly reflect the complex trade-offs that have guided its evolution.

animal behavior and cognition↗

Population-level inference for home-range areas

O_LIHome-range estimates are a common product of animal tracking data, as each range informs on the area needed by a given individual. Population-level inference on home-range areas--where multiple individual home-ranges are considered to be sampled from a population--is also important to evaluate changes over time, space, or covariates, such as habitat quality or fragmentation, and for comparative analyses of species averages. Population-level home-range parameters have traditionally been estimated by first assuming that the input tracking data were sampled independently when calculating home ranges via conventional kernel density estimation (KDE) or minimal convex polygon (MCP) methods, and then assuming that those individual home ranges were measured exactly when calculating the population-level estimates. This conventional approach does not account for the temporal autocorrelation that is inherent in modern tracking data, nor for the uncertainties of each individual home-range estimate, which are often large and heterogeneous. C_LIO_LIHere, we introduce a statistically and computationally efficient framework for the population-level analysis of home-range areas, based on autocorrelated kernel density estimation (AKDE), that can account for variable temporal autocorrelation and estimation uncertainty. C_LIO_LIWe apply our method to empirical examples on lowland tapir (Tapirus terrestris), kinkajou (Potos flavus), white-nosed coati (Nasua narica), white-faced capuchin monkey (Cebus capucinus), and spider monkey (Ateles geoffroyi), and quantify differences between species, environments, and sexes. C_LIO_LIOur approach allows researchers to more accurately compare different populations with different movement behaviors or sampling schedules, while retaining statistical precision and power when individual home-range uncertainties vary. Finally, we emphasize the estimation of effect sizes when comparing populations, rather than mere significance tests. C_LI

ecology↗

Locomotor compromises maintain group cohesion in baboon troops on the move

When members of a group differ in locomotor capacity, coordinating collective movement poses a challenge: some individuals may have to move faster (or slower) than their preferred speed to remain together. Such compromises have energetic repercussions yet research in collective behavior has largely neglected locomotor consensus costs. Here we integrate high-resolution tracking of wild baboon locomotion and movement with simulations to demonstrate that size-based variation in locomotor capacity poses an obstacle to collective movement. While all baboons modulate their gait and move-pause dynamics during collective movement, the costs of maintaining cohesion are disproportionately borne by smaller group members. Although consensus costs are not distributed equally, all group-mates do make locomotor compromises, suggesting a shared decision-making process drives the pace of collective movement in this highly despotic species. These results highlight the importance of considering how social dynamics and locomotor capacity interact to shape the movement ecology of group-living species.

ecology↗

Estimating encounter location distributions from animal tracking data

O_LIEcologists have long been interested in linking individual behavior with higher-level processes. For motile species, this upscaling is governed by how well any given movement strategy maximizes encounters with positive factors, and minimizes encounters with negative factors. Despite the importance of encounter events for a broad range of ecological processes, encounter theory has not kept pace with developments in animal tracking or movement modeling. Furthermore, existing work has focused primarily on the relationship between animal movement and encounter rates while no theoretical framework exists for directly relating individual movement with the spatial locations of encounter events in the environment. C_LIO_LIHere, we bridge this gap by introducing a new theoretical concept describing the long-term encounter location probabilities for movement within home ranges, termed the conditional distribution of encounters (CDE). We then derive this distribution, as well as confidence intervals, implement its statistical estimator into open source software, and demonstrate the broad ecological relevance of this novel concept. C_LIO_LIWe first use simulated data to show how our estimator provides asymptotically consistent estimates. We then demonstrate the general utility of this method for three simulation-based scenarios that occur routinely in biological systems: i) a population of individuals with home ranges that overlap with neighbors; ii) a pair of individuals with a hard territorial border between their home ranges; and iii) a predator with a large home range that encompassed the home ranges of multiple prey individuals. Using GPS data from white-faced capuchins (Cebus capucinus) tracked on Barro Colorado Island, Panama, and sleepy lizards (Tiliqua rugosa) tracked in Bundey, South Australia, we then show how the CDE can be used to estimate the locations of territorial borders, identify key resources, quantify the location-specific potential for competition, and/or identify any changes in behaviour that directly result from location-specific encounter probability. C_LIO_LIThis novel target distribution enables researchers to better understand the dynamics of populations of interacting individuals. Notably, the general estimation framework developed in this work builds straightforwardly off of home range estimation and requires no specialised data collection protocols. This method is now openly available via the ctmm R package. C_LI

ecology↗

Habitual stone-tool aided extractive foraging in white-faced capuchins, Cebus capucinus

AO_SCPCAPBSTRACTC_SCPCAPHabitual reliance on tool use is a marked behavioral difference between wild robust (genus Sapajus) and gracile (genus Cebus) capuchin monkeys. Despite being well studied and having a rich repertoire of social and extractive foraging traditions, Cebus sp have rarely been observed engaging in tool use and have never been reported to use stone tools. In contrast, habitual tool use and stone-tool use by Sapajus is widespread. We discuss factors which might explain these differences in patterns of tool use between Cebus and Sapajus. We then report the first case of habitual stone-tool use in a gracile capuchin: a population of white-faced capuchins (Cebus capucinus imitator) in Coiba National Park, Panama who habitually rely on hammerstone and anvil tool use to access structurally protected food items in coastal areas including Terminalia catappa seeds, hermit crabs, marine snails, terrestrial crabs, and other items. This behavior has persisted on one island in Coiba National Park since at least 2004. From one year of camera trapping, we found that stone tool use is strongly male-biased. Of the 205 unique camera-trap-days where tool use was recorded, adult females were never observed to use stone-tools, although they were frequently recorded at the sites and engaged in scrounging behavior. Stone-tool use occurs year-round in this population, and over half of all identifiable individuals were observed participating. At the most active tool use site, 83.2% of days where capuchins were sighted corresponded with tool use. Capuchins inhabiting the Coiba archipelago are highly terrestrial, under decreased predation pressure and potentially experience resource limitation compared to mainland populations- three conditions considered important for the evolution of stone tool use. White-faced capuchin tool use in Coiba National Park thus offers unique opportunities to explore the ecological drivers and evolutionary underpinnings of stone tool use in a comparative within- and between-species context.

animal behavior and cognition↗