Adaptive behavioural strategies to seasonal challenges by a semi-urban feral ungulate

Abstract

Seasonality, or temporal shifts between wet and dry seasons, profoundly affects the behavioural ecology of animals, particularly large herbivores, in (sub-) tropical climatic conditions. Behavioural strategies are crucial for overcoming challenges associated with seasonality. Group-level strategies to seasonality in the wild have received considerable attention, yet little is known about how large herbivores in human-dominated landscapes respond to seasonal challenges. Moreover, focusing solely on groups can obscure how individual animals of different sexes, ages, and personalities respond. We investigated a semi-urban feral population of a large ungulate, the water buffalo (Bubalus bubalis) (N=71) during a wet and a dry season. Individual body condition was non-invasively assessed to evaluate whether seasonality impacts physiology. To identify behavioural strategies, we collected data on feeding (grazing and browsing) and space use (core area and home range). Further, using a subset (n=30), we investigated the associations between personality and space use in the dry season. Body condition scores were highest during the wet season and then declined during the dry season, indicating an impact of seasonality on physiology. Older individuals were more affected than younger ones. Browsing increased during the dry compared to the wet season. While there was no change in core area use, home ranges expanded in the dry compared to the wet season. Regardless of season, females utilised home ranges larger than males. Females exhibiting higher social tension personalities had smaller core areas and home ranges than those with lower social tension. We show that buffalo employ behavioural strategies to overcome challenges associated with seasonality, and these strategies are contingent on intrinsic factors: sex, age, and personality. Our findings offer insights into the ecological principles -habitat use, resource utilisation, and competition- that govern the behavioural ecology of herbivores, and have implications for conservation and welfare in increasingly human-dominated and climate-sensitive landscapes.