Evening Bat

Scientific Name: Nycticeius humeralis

Weight: 7-14 grams

Wingspan: 26-28 centimeters

Distribution: Southern Ontario, Canada, most of the eastern United States, and northeastern Mexico.

Ecology and Behavior: This species usually inhabits buildings or tree cavities in summer. It almost never enters caves, although it sometimes joins the bats swarming about certain entrances in late summer. Maternity colonies in buildings sometimes contain hundreds of individuals. Smaller colonies may occur behind the loose bark of dead pines and in hollow cypress trees. Winter habitat is almost completely unknown, but evening bats accumulate large reserves of fat in autumn, sufficient for either hibernation or a long migration. This species emerges early and flies a slow and steady course. Heavy rain and cold temperatures retard activity, and females nursing young return to the roost periodically to care for their offspring.

Food Habits: Probably consumes a variety of insects

Reproduction: Young are born in nursery colonies from mid-May to mid-June. The usual litter size is two. As with most other species of bats, birth is by breech presentation. After the young are born, they grasp a nipple within 5-8 minutes. Newborns are pink, except for slightly darker feet, membranes, ears, and lips; their skin is so transparent that the viscera are visible. Lifespan is greater than 5 years.

Status of Populations: Uncommon through most of its range, but one of the most common bats throughout the southern coastal states.