Social organization of an endangered subtropical species, Eumops floridanus, the Florida bonneted bat

Many Chiropteran species are gregarious, yet much remains to be learned about details of the sociality of most species. This is especially true for the endangered Eumops floridanus (Florida bonneted bat). Scant knowledge of the species’ natural history and ecological interactions has precluded the development of effective conservation strategies. We investigated several aspects of the social organization of E. floridanus roosting in bat houses in southwest Florida: group size, group composition, group stability, and seasonality of reproduction. Our findings suggest the species has characteristics more common to tropical bat species than temperate ones. The average roost size was 10 individuals, with colonies in a harem social structure all three times in the year they were assessed. Adults were much more likely than sub-adults to be recaptured at the same roosts during subsequent capture sessions. We suggest that the availability and distribution of roosts may alter the social structure of these bats and ultimately limit local populations. We did not find evidence of a distinct seasonal birthing period matching that of other temperate bat species. Results suggests the species is aseasonally polyestrous, making non-volant E. floridanus vulnerable to disturbance across a larger portion of the year than other bat species in the US.