Ecology of the Big Brown Bat (Chiroptera: Vespertilionidae) in Northeastern Kansas

Study from November, 1962, through May, 1964, principally at Leavenworth, Kansas, of the big brown bat, Eptesicus fuscus, revealed that in a mine 64% of the bats in winter and almost 100% in summer were males. Hibernation began in early October and ended in April. Males hibernated earlier than did females. Hibernation was in cold areas having crevices. Many bats hibernated in clusters of 2-21. Body temperatures of hibernators matched those of the microenvironments. Homing ability was demonstrated by one bat carried 45 miles away. Coleoptera were the principal food. Copulation in autumn and parturition in spring produced, typically, one young per female. In adults, females averaged larger than males. Molt was in spring. Endoparasites and ectoparasites were recorded. Corresponding data on the species from elsewhere in its geographic range are summarized.