Births in captive stump-tailed macaques (Macaca arctoides)

In this report, nighttime births of 3 stump-tailed macaques observed at the Aizawl Zoological Park, India, are described. Continuous focal observations were collected a long with video and still photographs, on the 3 parturitions, from the first observed onset of labour. The average time taken for infant birth, beginning with visibility of the head at the vaginal opening, was 45 s. The births observed were similar in many respects, regardless of parity and social context. The average time taken for consuming the placenta was 4 min 4 s and the average number of contractions was 6.3. In all cases births occurred with the infant emerging in the occiput posterior position, assisted by the mother. Individual variations existed in the number of contractions, intercontraction intervals, self-examination of the anogenital region, duration of labour and the interval between infant birth and the delivery of the placenta. Each mother ingested the placenta completely, while holding her neonate, but without paying much attention to the neonate during placentophagia. Placentophagia appears to provide nutrition to the mothers. Detailed data on parturition in non-human primates, and particularly for Macacaarctoides , are still scarce. Data, such as those presented here, contribute to our understanding of primate birth and the adaptive pressures that shape parturition behaviour and reproductive success.