Reproduction and social organization in Peropteryx kappleri (Chiroptera, Emballonuridae) in Colombia

Abstract

The social organization and reproduction of Peropteryx kappleri were studied in small colonies inhabiting a series of abandoned coal mines at the base of the Western Andes near Cali, Colombia. All bats from each colony were individually marked and observed frequently for extended periods during both day and night. With few exceptions, all adult bats left the mines alone or in small groups shortly after 1800 h and returned between 0200 and 0600 h. Only one social group was found in each mine and these groups demonstrated high fidelity, not only to their mines of residence but also to particular preferred sites within them. Males did not exhibit territorial behavior and females dominated the organization of the social groups. Some individuals, usually females, occasionally visited other mines nearby, but always returned to their own social groups. The birth of young coincided with the two rainy seasons in this tropical region and some females bore young in both seasons during the year of observation. In the final days of the gestation period, females left the group to establish individual breeding territories some distance away from the rest of the group members. These sites were continuously maintained for parturition and rearing of the single young until weaning. From the day of birth, the young were invariably left alone in this territory during the night while the mothers were absent from the mine. After weaning, between 50 and 60 days of age, the young dispersed from the mines and the females returned to their position in the social group.