Sex and spatial proximity affect ungulate behavioral synchrony

Collective group decisions are important for the survival and reproduction of social mammals, with inter-individual interactions affecting group-level emergent behavior. Activity synchronization is an important aspect of 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 expected to influence the evolution of sexual segregation 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. 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 how sex and social relationships (dominance and affiliation) affected foraging, behavioral synchrony and proximity. We found that same-sex dyads were more likely to be synchronized than mixed-sex dyads, while differences in dominance and affiliation only affected dyadic synchrony when observations with high foraging activity were excluded. Focal animals were more synchronized with closest neighbors than with another randomly selected conspecific. Inter-individual differences can explain variation in activity, with synchronization being biased towards certain individuals by favoring animals in close spatial proximity and those of the same-sex.