Biology subjects

Hodgson, G. M. W.

Publications and source records attributed to Hodgson, G. M. W..

3 recordsLinked to original sources

bioRxiv2025

Spatial proximity and dyadic social relationships affect ungulate behavioral synchrony

Collective group decisions are important for the survival and reproduction of social mammals, with inter-individual interactions often driving group-level emergent behavior. Activity synchronization is an important collective behavior, with differences in nutritional requirements leading to foraging asynchrony. Individual variation between animals (such as sex or social relationships) are predicted to affect ungulate synchronization and spatial proximity, with between-sex differences consequently influencing sexual segregation evolution in ungulates. Although investigated independently, the relative roles of sex, sociality and proximity in synchronization are rarely investigated concurrently, especially in regards to affiliative relationships. Asynchrony influences fission-fusion dynamics and social segregation, but little is known how short-term changes in synchrony affects fission. Using a mixed-sex group of feral cattle (Bos taurus), we evaluated the supporting evidence for several predictions arising from the current understanding of synchronization in ungulates. We investigated if sex and social relationships (dominance and affiliation) affected foraging, behavioral synchrony and proximity. We also investigated whether group synchrony affected short-term changes in group size (fission events). We found that same-sex dyads were more likely to be synchronized than mixed-sex dyads, but differences in dominance and affiliation did not affect dyadic synchrony. Focal animals were more synchronized with closest neighbors than with another randomly selected conspecific. Reduction in group size was more likely when group synchrony was lower, highlighting the importance of asynchrony in temporary movement decisions. Inter-individual differences can explain variation in collective behavior, with synchronization being biased towards certain individuals by favoring animals in close spatial proximity and those of the same-sex. LAY SUMMARYIn ungulates, differences in energetic requirements lead to variation in activity, resulting in social and sexual segregation. However, sex, social relationships and spatial proximity are rarely investigated concurrently in relation to synchrony. We investigated synchronization and fission in a feral ungulate relative to individual differences in social relationship and proximity. Sex and proximity affected synchrony and fission events were more likely when synchrony was lower, highlighting the underlying processes in the evolution of sexual segregation.

zoology↗

bioRxiv2025

Sexual dimorphism and phenotypic plasticity in a subtropical feral bovid Bos taurus (Artiodactyla: Bovidae).

Phenotypes reflect how organisms adapt to their environments. Hong Kong (HK) feral cattle, a crossbreed of Bos taurus taurus and Bos taurus indicus, present an opportunity to study these adaptations in one of the very few global cattle populations not directly controlled by humans. These cattle are free-ranging since their release from farms in the 1970s. HK has a subtropical climate, characterized by high humidity and temperatures during the wet season, and scarce precipitation during the dry season. We studied seasonal coat colour changes in HK feral cattle, and sexual dimorphism in body size and horn length. We provide the first evidence of seasonal changes in coat colour in cattle, with paler coats being more common in the wet season, while darker coats prevailed in the dry season. These seasonal changes were influenced by temperature, humidity, solar radiation, and body condition. We found that males were larger and had longer horns than females. Our results show a male-biased sex dimorphism in the HK feral cattle. Additionally, our findings suggest that thermoregulation costs drive colouration in these cattle. The phenotypic plasticity we demonstrate in these subtropical feral cattle improves our knowledge of the adaptations of ungulates to their habitat.

zoology↗

bioRxiv2023

Sex and dominance status affect allogrooming in free-ranging feral cattle

Social interactions are fundamental properties of gregarious species, helping to establish dominance hierarchies and maintain social bonds within groups, thus having significant effects on fitness. Cattle (Bos taurus) are social ungulates which engage in affiliative and agonistic relationships with other individuals. Although there are approximately 1.5 billion cattle on the planet, the opportunity to research cattle behaviour in free-ranging groups is rare, as there are few feral populations worldwide. Cattle engage in positive social behaviours such as allogrooming, where one individual licks the body of another. The relationship between affiliative behaviours and other individual characteristics (such as sex and dominance status) are frequently studied in other gregarious species, but are largely undetermined in cattle. To investigate the relationships between sex, dominance status and allogrooming, we observed a mixed-sex feral cattle herd in Hong Kong, recording dominance interactions and allogrooming events. We found that dominant females received more allogrooming than subordinate females, but subordinate females did not perform more than dominant ones. Males performed allogrooming more towards females than other males, but females groomed both sexes equally. Sex affected dominance position, with males obtaining higher status than females, but not all females were subordinate to males. These preferential allogrooming patterns improve our knowledge of sex-specific interactions, and help us to understand the dynamics of agonistic and affiliative behaviours in multi-male, multi-female ungulate groups. Studying a free-ranging feral population provides us with a unique insight into ungulate behavioural patterns and the evolution of cattle social behaviours.

animal behavior and cognition↗