Ecological Associations of Bats (Mammalia: Chiroptera) in the Upper Mobile-Tensaw River Delta, Alabama

Abstract

Relatively little is known about most of the 15 species of bats in Alabama. Especially scarce are data on species occurring in southern Alabama, including the Mobile-Tensaw Delta region. Because there are significant recent acquisitions of tracts of land into the public trust within the Mobile-Tensaw Delta region in southern Alabama, it was especially desirable to obtain an accurate biological survey. Objectives were to conduct a field survey, and to use GIS (Global Information Systems) software to identify ecological associations of bats. At each collection locality, habitat, species captured, date and time of capture, sex, age, and reproductive condition were recorded for each individual. Mist nets were used to capture bats, abandoned buildings were searched, and Alabama Department of Conservation and Natural Resources, Division of Wildlife and Freshwater Fishes provided specimens. These data were then used to create 100-m, 250-m, and 500-m buffers for spatial analysis. Seven species of bats were documented in the Upper Mobile-Tensaw River Delta. Statistical analysis of relationships between occurrence of bats, type of timber, and age class of timber showed both positive and negative statistical relationships at all three spatial scales (100, 250, and 500 m). These varied relationships suggest that a complex matrix of multiple timber types and age classes of timber may produce the most diverse fauna of bats.