Structure and social dynamics of harem groups in Artibeus jamaicensis (Chiroptera: Phyllostomidae)

The Jamaican fruit-eating bat (Artibeus jamaicensis) is one of the most common Neotropical chiropterans, but comparatively little is known about structure and dynamics of its social groups. In two caves of the Yucatán Peninsula, Mexico, we found Jamaican fruit-eating bats forming harem groups, consisting of 4-18 females and 1-2 males, inside solution cavities that develop on the ceiling of caves. Other individuals roosted solitarily in the same caves, but outside solution cavities. We identified three types of males: dominants (one in each harem group), subordinates (present only in the largest harems), and satellites (not associated with a harem). Dominants were larger and heavier than males of the other two categories. During the 2-year study, harem groups always roosted in the same cavity and presented a high degree of stability, with few changes in composition. Satellite males and solitary females, in contrast, shifted roosting sites frequently and never formed cohesive groups. Adult females performed more movements from and to harem groups than males, and those movements were less frequent during the breeding season. Harems of the Jamaican fruit-eating bat presented subordinate males in large groups and differ from those of other phyllostomids in the lower degree of cohesiveness shown by females.