Other Mammals - Sounds Wild
Bat monitoring


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Bat monitoring

On a summer night a bat is flitting about the street light, catching moths and insects drawn to the light. It's almost certainly a little brown bat, the most common and widely distributed bat in Alaska.

Little brown bats eat at average of half their body weight in insects a night; a lactating female may eat as much as 110% of her body weight. A female bat gives birth to only one pup in the early summer. That's a low reproductive rate, but little brown bats can live more than 30 years - an amazing lifespan for a small mammal. Mice and other small mammals rarely live longer than a year or two.

In early summer, little brown bats sexually segregate. If this bat is a female has a pup, she's part of a maternity colony - a group of females and young that roost together. In Interior Alaska, these have been found ranging in size from 70 to 200 bats. A large maternity colony discovered in Juneau was home to more than 1,000 bats in the summer of 2013.

Fish and Game has established a network of year-round acoustic monitoring station across Southeast Alaska to learn more about when bats emerge in spring, when they disappear in the fall, and to compare seasonal activity patterns across the region. Biologists are trapping and radiotagging little brown bats to learn more about the timing of reproduction and migration, the locations of maternity and day roosts, and where little brown bats go in winter.