Reproduction in a semi-captive herd of pampas deer Ozotoceros bezoarticus

Information on reproductive traits of semi-captive breeding of the pampas deer Ozotoceros bezoarticus arerunguaensis, an endangered species, was registered during 20 years. Birth events were monitored every 1-2 days from 1981 to 2000, and birth date, mother and father identities, sex and mass of fawns were all registered. Although births occurred throughout the year, a seasonal pattern with a peak in spring was observed. Dispersion of births throughout the year increased in multiparous females that previously gave birth four times or more. The interval between two consecutive parturitions was ~10 months, independently of the mother parity and of the sex of the fawn, but differed according to the timing of the previous birth. Individual variability in interbirth intervals was significantly higher in primiparous than in multiparous females. Hinds born in semi-captivity had their first birth earlier in their life than hinds that were originally captured (at <1 month of age) from the wild. Single fawns were observed in all but one birth, in which twins were observed. Sex ratio was not influenced by the female parity, the season, or by the father identity. Only the mother identity influenced offspring birth mass.