High-resolution tracking of hyrax social interactions highlights nighttime drivers of animal sociality

Abstract

Network structure is a key driver of animal fitness, pathogen transmission, information spread, and population demographics in the wild. Although a considerable body of research applied network analysis to animal societies, only little effort has been devoted to separate daytime and nighttime sociality and explicitly test working hypotheses on social structures emerging at night. Here, we investigated the nighttime sociality of a wild population of rock hyraxes (Procavia capensis) and its relation to daytime social structure. We recorded nearly 15,000 encounters over 27 consecutive days and nights using proximity loggers. Overall, we show that hyraxes are more selective of their social affiliates at night compared to daytime. We also show that hyraxes maintain their overall network topology while reallocating the weights of social relationships at the daily and monthly scales, which could help hyraxes maintain their social structure over long periods while adapting to local constraints and generate complex social dynamics. These results suggest that complex network dynamics can be a by-product of simple daily social tactics and do not require high cognitive abilities. Our work sheds light on the function of nighttime social interactions in diurnal social species.