Insect Abundance and Variability in an Urban-Rural Landscape and Comparison to Foraging Habitat Selection of Bats

Abstract

I conducted a study of the relationship between prey availability and foraging habitat selection of Indiana bats (Myotis sodalis), big brown bats (Eptesicus fuscus), eastern red bats (Lasiurus borealis) and evening bats (Nycticeius humeralis) in an urban-rural landscape matrix of southwestern Indianapolis. Insects were collected from nine different habitat types found within the range of these species. Insect data were collected from 2006 to 2008 using sticky traps placed in each habitat type. Habitat types were ranked by importance to each bat species (based on previous studies) and then compared to the average number of prey insects captured per habitat sticky trap. Only the average number of insects captured per habitat sticky trap that were big brown bat and eastern red bat prey varied significantly between all nine habitat types. The average number of prey insects captured per habitat sticky trap that were Indiana bat, big brown bat, eastern red bat and evening bat prey were strongly significantly different between sampling dates within seasons. The average number of prey insects captured per habitat sticky trap that were big brown bat and evening bat prey varied significantly between sampling dates between seasons. The average number of prey insects per habitat type did not correlate significantly with habitat selection by any of the four bat species.