Reproductive assessment and preliminary evaluation of assisted reproductive technologies in drills (Mandrillus leucophaeus)

The drill ( Mandrillus leucophaeus ) is listed as endangered by the IUCN and its population is decreasing due to habitat loss and human activity. The European Endangered Species Programme (EEP) aims to consolidate a self-sustaining ex-situ population, and there is a need to develop appropriate assisted reproductive technologies (ART) that could help to increase breeding rates and/or genetic variability, or at least preserve sexual cells for the future. In 2006, a new breeding male drill arrived at Barcelona Zoo but was unable to mate appropriately with females during oestrus. Several attempts at sperm cell recovery by electro-ejaculation were performed on the breeding male in order to ascertain his fertility, while female oestrous cycles were visually monitored every month. In all, five electro-ejaculation and artificial insemination (AI) attempts were undertaken. Good samples of sperm were gathered and preserved, but the optimal moment for insemination needs more investigation, as no female got pregnant. To our knowledge, this is the first report of attempted AI in drills under anaesthesia and provides some valuable information for the future development of ART in endangered cercopithecids.