hoary bat hangs from a branch

A Batty October: Bat Week 2020

Published10/24/2020 , by Adam Hartman, gallery programs assistant

Bat Week AND Bat Month—batception! With Halloween right around the corner, October is the perfect time to dial up the bat love by highlighting bats’ unique traits, charm, and ecological importance instead of the spooky stigmas that feed into their batty reputation.

The first thing that comes to mind when many of us think of bats is flight. Flight has evolved convergently, or separately in several different groups of animals like birds, insects, and flying reptiles (all extinct) such as pteranodon. Other mammals including flying squirrels and flying lemurs (culugos) can glide, but bats are the only mammals capable of powered flight. 

Each group of flying animals has evolved different structures for flight. Similar to what we find in birds, bat wings are formed from their forelimbs (equivalent to our arms). Unlike birds, however, bat wings gain their characteristic webbed appearance from skin spread between each finger, rather than having fused hand bones and feathers. Bat wings are built for maneuverability over speed—a crucial trait for aerial hunters like bats that need to quickly change direction mid-flight.

Bats feed on all kinds of insects, including many we consider pests. From tiny mosquitoes to tough beetles, bats will eat whatever is accessible for their size and location. Moths and beetles whose larvae feed on crops are common prey for bats who roost near agricultural fields, and mosquitoes (a nuisance for many animals) are an easy mid-flight snack for many bat species. A single bat may have little effect on an insect population, but colonies of hundreds, thousands, and even millions of bats can contribute to keeping insect populations under control.

Not all bats eat insects, though. Some bat species are carnivorous and specialized to hunt specific prey, including fish, frogs, other bats, and blood! Fruit-eating bats are incredible vehicles for seed dispersal, and other species, like the lesser long-nosed bat, are the primary pollinators of night-blooming saguaro and organ pipe cactuses.

As Halloween approaches, remember bats and the important ecological roles they play. There are over 1,200 species of bats around the world. In Minnesota, we have only seven (maybe eight!)—all are nocturnal, insectivorous, and belong to the family Vespertillionidae. Though members of the same family, they are surprisingly diverse: we have both solitary and colonial bats, some species migrate in the winter, and others hibernate for much of the year. Get to know each of Minnesota’s bats below, and let us know which species is your favorite.

Common Name: Little brown bat or little brown myotis

Scientific Name: Myotis lucifugus

Sociality: Colonial

Winter Behavior: Colonial hibernation

Fun Fact: Shares a similar name with the big brown bat, another MN species, though the two belong to different genera (plural of “genus”; subgroups within a family) and are not closely related. Little brown bats occupy three different roosts based on their stable ambient temperature: day, night, and hibernation roosts.

little brown bat