Reproductive ecology of the orange horshoe bat, Rhinonycteris aurantius (Hipposideridae : Chiroptera), a tropical cave-dweller

Abstract

Rhinonycteris aurantius has a seasonally monoestrous reproductive pattern. Males do not become sexually mature until their second year, at about 16 months of age. Mature spermatozoa were observed in the testes in April, with increasing numbers of sperm recorded until copulation in July, declining numbers from August to October and none observed during the wet season from December to March. Females attain sexual maturity at seven months of age. The gestation period is prolonged (approximately 150 days) from July to December with the young weaned and independent by late February. Despite this species' utilisation of hot and humid caves during the dry season, late pregnancy, parturition and weaning take place away from the cave environment. The first three months of pregnancy in females and the production of sperm in males occurs during periods of low food availability. However, there is coincidence of maximum food availability with late pregnancy and lactation, obviating sperm storage and/or delayed embryonic development.