A Comparative Approach of Personality Between Forest and Urban Dwellers: Linking Urbanization and Social Position to Personality Variation in a Synanthropic Primate (Macaca fascicularis)

Abstract

Urbanization threatens wildlife by reducing habitat size and connectivity, forcing animals closer to human settlements. While some species, known as synanthropes, thrive in urban areas, cities are dynamic and unpredictable environments. Personality appears to be a crucial mechanism for animals to cope with urban stimuli and associated risks. Previous research has shown that this plastic mechanism interacts with other factors, such as social position within a group. In this study, we aim to better understand how wild animals respond to anthropogenic pressures. We investigated the personality and social networks of long-tailed macaques (Macaca fascicularis), an opportunistic primate species in Bali, Indonesia. We divided our research into two main objectives. (1) We determined the role of social centrality (strength of connections) within affiliative networks (proximity, grooming, and contact) in the personality of macaques living in a protected forest habitat while controlling for the influence of sex, age, and dominance rank. (2) We compared the personality structure of the forest group with that of a group inhabiting an urban habitat, (a) to test the impact of habitat type and individual synanthropy degree on personality traits and (b) to evaluate the presence of behavioral syndromes within habitats. We found that social centrality predicted certain personality traits in macaques, although it was true for the proximity and contact networks. Anxiety decreased in more central females, whereas it increased in more central males. Peripheral individuals were more neophiliac than central individuals. Conversely, central individuals were more assertive with conspecifics, while they were less assertive towards humans. Contrary to our predictions, we did not find any impact of habitat and synanthropy on shared personality dimensions - Assertiveness and Dominance - of both groups. We detected a Dominance-Anxiety syndrome in the urban group but none in the forest group. Overall, our results highlight the association of certain personality traits with specific social positions in a macaque group. These two components could significantly contribute to individual fitness in specific environments, such as cities, by impacting exposure to anthropogenic factors. Although our study failed to demonstrate how urbanization impacts personality in a synanthropic species, we believe this research warrants further investigation with a larger dataset. A better understanding of wildlife adaptation to anthropogenic habitats is necessary to mitigate the risks associated with the wildlife-human interface.