Diet of the Endangered Indiana Bat (Myotis sodalis) on the Northern Edge of Its Range

Dietary preferences of Indiana bats were determined by analyzing 382 fecal pellets collected beneath roost trees in southern Michigan, over parts of 3 yr. Although terrestrial insects (Lepidoptera and Coleoptera) usually dominated the diet of Indiana bats in more southern states, those in Michigan consumed mostly insects associated with aquatic environments. Indiana bats in Michigan ate primarily Trichoptera (55.1% of volume) and Diptera (25.5%), followed by Lepidoptera (14.2%) and Coleoptera (1.4%). Consumption of Diptera was highest during lactation (48.2%), whereas consumption of Lepidoptera was least during this time (7.7%). Although most insectivorous bats do not prey on mosquitoes (Culicidae), these insects were a consistent component of the diet of Indiana bats and were eaten most heavily during pregnancy (6.6%).