PREY SELECTION BY BIG BROWN BATS (EPTESICUS-FUSCUS) AND COMMON NIGHTHAWKS (CHORDEILES-MINOR)

Trichoptera >5 mm body length were the most important prey item for both bats and birds, constituting at least 50% of the diet in terms of frequency. Hymenoptera and Coleoptera were eaten by C. minor in proportions greater than expected on the basis of availability, while E. fuscus occasionally ate more Coleoptera and Diptera than would be expected. The bats showed no preference for, or avoidance of, Hymenoptera. Neither species ate Chironomidae, even though these insects constituted at least 60% of available prey items. Apparent prey selection by nighthawks and bats but may reflect constraints of prey detection. -from Author