Rut-induced changes in the activity budgets of male tropical ungulates: Eld’s deer on Hainan Island

Aspects of time budgets, activity patterns and rut-related changes in behavior are well documented in temperate ungulates; however, the application of this understanding to tropical and sub-tropical ungulate species has attracted less attention and remains an area that may re-shape our knowledge of ungulate behavior. Eld’s deer Cervus eldi hainanus has a tropical and sub-tropical distribution on Hainan Island, China, and males have an extended rut exceeding five months during which they do not maintain harems or defend resources. We studied males from the only remaining population on Hainan Island, and describe rut-related changes in behavior by collecting data on time budgets and activity patterns. We show that male Eld’s deer do not follow a strict crepuscular activity pattern, do not spend the majority of their time foraging and do not increase foraging nor display rut-induced hypophagia during rut, in obvious contrast to temperate ungulates. These results are discussed in light of current hypotheses explaining the proximate mechanisms governing feeding time in ungulates, while appreciating the need for further research.