DISCOVERY FILE: Indiana Bat
Biology and Migration
Indiana bats are quite small; they weigh 1/4 of an ounce, which is the mass of about three pennies. Their body is about the size of your thumb. In flight they have a wingspan of 9 to 11 inches. Their fur is dark-brown to black. Indiana bats live an average of 15 years and produce only a single pup each summer. Female bats form maternity colonies and bear and raise their pups together from early May to late June. During the summer they roost (sleep) under the peeling bark of dead and dying trees. They eat a variety of flying insects found along rivers or lakes and in uplands. In the late summer and early fall, Indiana bats migrate (to move or travel to another area or region, sometimes at regular or annual times)to the place they will spend the winter. They hibernate during the winter season in hibernacula (caves, and occasionally abandoned mines bats use for hibernating).
Environmental Science – Global Change
Indiana bats are found over most of the eastern half of the United States. Almost half hibernate in caves in southern Indiana. The 2009 population estimate is about 387,000 Indiana bats. This is less than half the bats that were living in 1967 when the bats were listed as an endangered species. Their numbers had increased between 2000 and 2005 thanks to conservation efforts, but then decreased again due to a disease caused white-nose syndrome.
The Indiana bat is an endangered species, partly due to people disturbing hibernating bats in caves during the winter.Indiana bats are vulnerable to being disturbed because they hibernate in large numbers in only a few caves. Other threats include using caves for tourism. When humans change cave entrances, they also hurt the bat’s ability to move freely in their caves. These changes to caves cause change in air flow, temperatures, and humidity levels. Loss of summer habitat, exposure to pesticides and other contaminants, and the white-nose syndrome (see below)all contribute to the Indiana bat’s endangered status.
White nose syndrome (WNS) is an illness that has killed over a million bats since 2006, when dead and dying bats, with a distinctive “white nose” were first observed.
Conservation – How to Help
Humans can manage forests to maintain and create Indiana bat habitat. Indiana bats like to live in older forests that have large dead and dying trees, so cutting down mature forests is not good for the future of Indiana bats. Keeping forested land at least 25 feet wide along streams, ponds, lakes, and wetlands will help the bats survive.
Resources
ArKive – Explore Endangered Species
Indiana Bats, Kids and Caves, Oh My! An Activity Guide for Teachers:
BioKidsIndiana Bat fact sheet
Indiana Bat fact sheet from the US Forest Service: