Big Brown Bat
Photo © Greg Flaxa
Description: Largest have 13” wingspan, 3 ¼” body, 2” tail. Weighs up to 18 grams, approximately the weight of 3 nickels and a dime. One of the fastest bats, up to 13 feet a second pursuing prey. Catches insects at the tops of trees, 100 feet or more in height. Jaws adapted to eating beetles, a favorite food, but these bats feed on a wide variety of insects.
Big Brown Bats Roosting in a Building
(Click on the image to see a larger
Photo © Merlin Tuttle
Spring/summer: Emerges slightly before sunset, and is often seen flying over residential neighborhoods catching insects and/or migrating to places like Capitol Lake. Feeds over agricultural land as well; very beneficial to farmers. Males usually solitary; females form small maternity colonies of 50-200 females.
Fall/winter: Very cold hardy, starting hibernation later than most other bats and emerging at times to hunt in the winter. May remain in the local area in attics or walls that do not drop below freezing and in this temperate area may not migrate to hibernate.