bioRxiv Science⌕ Search

Biology subjects

Goldsborough, Z.

Publications and source records attributed to Goldsborough, Z..

3 recordsLinked to original sources

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↗

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↗