Pere David's deer  (Elaphurus davidianus)

Since this deer is so rare in the wild, the only observations of its behaviour come from captive populations (5). This species is social and lives in large herds, except before and after the breeding season, or 'rut', in June. At these times males leave the herd to feed intensively and build up strength, and before the rut, females bunch together in several groups (6). A stag joins each group of females and engages in fights with rival males using its antlers, teeth and forelegs (2). The successful stags win dominance and, as the fittest males, are able to mate with the females. During the rutting season males do not feed, as every moment is spent trying to establish dominance over other males. Therefore, after leaving the females, males will begin feeding again and quickly regain weight. After a gestation period of 288 days, females give birth to one or two fawns (6).