Social structure and temporal composition in a colony of Nyctinomops laticaudatus (Chiroptera: Molossidae)

Abstract

Little is known about the social structure of the molossid bats in the Neotropics. During 4 observational periods (2006/2007), we studied the spatial distribution and temporal variation of a colony of Nyctinomops laticaudatus inside the Governor’s Palace at the Archeological Zone of Uxmal, Yucatán, Mexico. We surveyed 66 roosting cavities consisting of mixed groups of males and females. This particular association (mixed groups) occurred throughout the study, but bats shifted group membership by moving continuously from one group to another. Because of this pattern, we were unable to describe a unique social structure and we proposed a promiscuous system for the species. During the 2 year study, we identified only adult bats inside cavities, while newborns were observed roosting outside cavities in adjcent walls. Resting was the most common activity inside cavities, but visits and copulations were also recorded. In groups of Nyctinomops laticaudatus both sexes are presented and differ with other bats due to their lower degree of cohesiveness.