Eastern Pipistrelle (Tri-Colored Bat)

The eastern pipistrelle has tri-colored dorsal hairs, thus its common name of tri-colored bat.

Tri-colored bat. NPS-PD.

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About This Species

Slightly larger than the canyon bat​, the eastern pipistrelle is readily distinguished by its tri-colored dorsal hairs, dark brown at tips and bases with a band of yellow between. There is a single report of the eastern pipistrelle in Colorado, in Greeley.

Living with Bats

There are 18 species of bat that call Colorado home. These amazing mammals are not only fantastic insect control, but are also valuable pollinators. Learn more about how humans and bats can live in harmony in our guide.

Bat Conservation

    Bats remain one of the most mysterious land mammals, especially in Colorado, where 18 species spend at least part of the year. For example, the little brown bats in our state seem to hibernate differently than those on the east coast, and we are constantly learning about their whereabouts, habitats and behaviors. Our current research suggests that bat populations in Colorado are doing quite well. 

    One little brown bat can eat up to 18,000 small insects (like mosquitoes) each night. Their economic impact is estimated to be billions of dollars, and much of the agricultural industry relies on their insect control. 

    Beyond their economic impact, bats flaunt some impressive adaptations. They are the only mammal that truly flies, which requires a very unique anatomy. Their upside-down lifestyle requires adaptations in their “feet” to consistently grip. If people hanged upside down for even an hour, we’d lose consciousness; bats have developed amazing blood pressure accommodations to fit the lifestyle.  

    We are currently involved in a monitoring partnership called the North American Bat Monitoring Program (NA Bat). The program utilizes acoustic surveys to collect information on bat populations without interfering with their behaviors. We also are using PIT tags, like the chips put in household pets, to monitor a number of maternity sites.  While data collection will take years, we’ve already learned new information about Colorado’s bat ​​population, the most heartening of which is that the population appears larger and more widespread than we’d thought. This is an excellent start to learning more about the species, but we’ve got lots of problem-solving and technological innovation left to do.

    Our priorities also include learning more about bats so that we are prepared for the potential spread of White-nose Syndrome. Finding and monitoring bats is crucial to this effort, but also comes with its own challenges. Because bats are small, flying mammals, much of the equipment used to track other species is too heavy for them. And during the winter, Colorado bats are very elusive, choosing to hibernate in small groups often in locations that are inaccessible to people.

    More Information:

    Physical Characteristics

    Total length: 70-90mm, forearm: 30-35mm, wingspan: about 210mm, weight: five to eight g.​
     

    Range

    This is a bat of eastern North America, ranging from Nova Scotia and Minnesota south to Mexico, Guatemala and Belize.

    Habitat

    The eastern pipistrelle is an animal of open deciduous forests. The animals are not strongly migratory, typically spending the summer in the same general region as the hibernaculum.

    Diet

    Eastern pipistrelles emerge early, while still light, to forage in clearings or over still water for smaller insects, including moths, flies and beetles.

    Reproduction

    Adults in reproductive condition have been captured in the southeastern U. S. in winter and spring. Twin births are the rule in late spring or early summer.

    Mammal
    Perimyotis subflavus