The lion-tailed macaque (Macaca silenus), endemic to rainforests of the Western Ghats; in southern India, is an endangered species. Most of its population now lives in fragmented pockets of rainforests. Considerable research has been carried out on its reproductive biology both on wild and captive populations in North America and Europe. We review studies carried out on birth seasonality, life-history parameters, and reproductive physiology and behaviour. The captive populations differ considerably from wild populations on several parameters of reproductive biology. Because of a low population turnover in this species due to a delayed age at first birth and long inter-birth intervals, and further degradation of its natural habitats, rapid population replenishment or augmentation is unlikely. This article shows that the study of reproductive biology may provide an important key to the conservation of this species. It also indicates that several aspects of reproductive biology of lion-tailed macaque still remain to be addressed
