Date of Award

January 2012

Degree Type

Open Access Thesis

Document Type

Master Thesis

Degree Name

Master of Science (MS)


Biological Sciences

First Advisor

Charles L. Elliott

Department Affiliation

Biological Sciences


Knowledge is lacking regarding the dietary habits of northern (Myotis septentrionalis) and big brown bats (Eptesicus fuscus) in Kentucky. The objective of this study was to determine the prey items consumed by both species at three sites in western Kentucky. Totals of 103 fecal pellet samples from northern bats and 36 fecal pellet samples from big brown bats were collected in 2003 and 2004. Overall prey items found within the samples collected for both species indicated their diets were similar (Sorensen's coefficient; SS= 0.72); with the most common insect orders being Coleoptera, Lepidoptera, and Hemiptera. Big brown bats consumed a significantly greater amount of the Chinavia hilaris, a member of the Hemiptera order, (P < 0.05; z = 8.29) than did northern bats (35.7 % to 0 %). Northern bats consumed a greater amount of lepidopterans (z = - 6.04) than did big brown bats (27.1 % to 0.2 %). Adult male (n = 34) and adult female (n = 40) northern bats consumed similar prey items (SS= 0.85). Adult male diets of northern (n = 34) and big brown bats (n = 8), were dissimilar in prey items consumed (SS = 0.56). Adult male northern bats consumed a significantly greater amount of lepidopterans (z = - 3.07) than did their big brown bat counterparts (27.5 % to 0 %). Adult female diets among northern (n = 40) and big brown bats (n = 5) had very little similarity in prey items consumed (SS = 0.43). Big brown bat adult females consumed a significantly greater amount of Chinavia hilaris (order Hemiptera; z = 3.61) than did adult northern bats (0 to 19 %). Northern bat adult females consumed a significantly greater amount of lepidopterans (z = - 2.53) than did adult female big brown bats (30.6 % to 0.3 %). In general, big brown bats appear to be a "beetle strategist", typically feeding mainly on hard-bodied insects, particularly beetles (Coleoptera) and true bugs (Hemiptera); while northern bats tend to consume mostly soft-bodied insects like moths (Lepidoptera).