Prey Selection by Five Species of Vespertilionid Bats on 

 Sapelo Island, Georgia 



Timothy C. Carter, Michael A. Menzel, Diane M. Krishon 



Daniel B. Warnell 



School of Forest Resources 



and 



Joshua Laerm 



Museum of Natural History 



University of Georgia, Athens Georgia 30602 



ABSTRACT. - Prey items obtained from fecal samples of 132 individ- 

 uals representing five species of vespertilionid bats were compared to 

 available prey as determined by insect light trapping in foraging habi- 

 tats on Sapelo Island, Georgia. Four orders of insects dominated the 

 diet of these bats: Coleoptera, Hymenoptera, Lepidoptera, and 

 Hemiptera. Homoptera and Diptera were present in smaller propor- 

 tions. All five bat species exhibited significant selection for or against 

 certain insect orders. The evening bat (Nycticeius humeralis) consumed 

 Coleoptera and Hymenoptera in proportion to their availability, but sig- 

 nificantly fewer Homoptera than were available in the foraging habitats. 

 Differences in feeding selectivity were observed between sexes and age 

 groups. Adult male and juvenile evening bats consumed significantly 

 fewer Coleoptera and more Hymenoptera than were available in the for- 

 aging habitats; adult females showed little feeding selectivity. The 

 Seminole bat (Lasiurus seminolus) consumed Homoptera and Diptera 

 in significantly lower proportion to their availability. The eastern pip- 

 istrelle (Pipistrellus subflavus) consumed significantly more Lepi- 

 doptera and fewer Coleoptera and Homoptera in proportion to their 

 availability. The big brown bat (Eptesicus fuscus) fed mostly on 

 Coleoptera and Lepidoptera, whereas the northern yellow bat (L.inter- 

 medius) consumed only Coleoptera and Hymenoptera. 



Twelve species of bats occur in Lower Coastal Plain ecosystems of 

 South Carolina, Georgia, and northern Florida (Barbour and Davis 1969, Hall 

 1981). With the exception of Zinn and Humphrey's (1981) study of prey avail- 

 ability and prey selection of the southeastern bat, Myotis austroriparius (Rhoads 

 1897), only anecdotal comments regarding foraging behavior of bats inhabiting 



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