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western red bat

Lasiurus blossevillii

What do they look like?

Western red bats are medium sized, with red or reddish-brown fur. Their ears are short and rounded, and their nose is small. They have large heads compared to other bat species, and their red fur makes them easy to tell apart from other bat species, except the eastern red bat, Lasiurus borealis. Their body ends in a furry triangle-shaped point. While their body is heavily covered in fur, their wings are not, and are usually darker in color. They are about 103 mm in length. (Lesson and Garnot, 1997; Pierson and Rainey, 1998; Texas Parks and Wildlife Department, 2013)

  • Average length
    103 mm
    4.06 in
  • Range wingspan
    35 to 45 mm
    1.38 to 1.77 in

Where do they live?

Lasiurus blossevillii, the western red bat, is found from Canada to South America. It lives as far north as British Columbia, most of western United States, throughout Mexico and Central America, and as far south as Argentina, Brazil, Bolivia, Uruguay, and Chile. It is also present in Tobago and Trinidad, and can be found in the Galapagos. (Bucknell Univesity, 2008; Pierson and Rainey, 1998)

What kind of habitat do they need?

When they aren't flying, western red bats can be found in trees and shrubs in forests, 1.5 to 12 m above the ground. The trees that they live in are often close to rivers and other bodies of water, as well as fruit trees in orchards. They sometimes even live in caves. They can often be seen hunting for food in rural and suburban areas, around streetlights and other light sources. (Pierson and Rainey, 1998; Pierson and Rainey, 2004)

How do they reproduce?

There is little known about the mating habits of western red bats. Related bats have a huge variety of mating patterns, so its difficult to say how western red bats mate. (McCracken and Wilkinson, 2000)

Red bats can have up to five pups in a litter. They mate in late summer to early fall, when there are the most insects available to eat. Females can store the sperm from mating until after hibernating through the winter, so they are able to have the pups when the weather is warm and insects are available again. After the young are born, they are able to fly 3 to 6 weeks later. (Texas Parks and Wildlife Department, 2013)

  • Breeding season
    Lasiurus blossevillii breed during late summer to early fall.
  • Range number of offspring
    1 to 5
  • Average number of offspring
  • Range gestation period
    80 to 90 days

There is not much known about the parental care of western red bats, but a related bat, Lasiurus borealis, has been studied, and probably has similar habits. During the day, a Lasiurus borealis mother lets her young cling to her while she hangs from a tree or shrub. The babies also hang from twigs or leaves while they cling to her. During this time, the young are constantly moving, by stretching, cleaning themselves, or interacting with their mother. She provides milk for them during this time as well. This lasts for awhile, until the young are 90% of their adult size. The young cannot fly or hunt for food before this time. (Barbour and Davis, 1969; Racey and Swift, 1995)

How long do they live?

It is not known how long western red bats live for.

How do they behave?

Other related bat species undergo migrations every year, traveling to warmer regions during the winter, while other red bat species hibernate in leaf litter during the winter instead of migrating. It is not sure how western red bats survive the winter, but many live in warm regions year round and probably do not have to migrate. Western red bats tend to hang in trees alone during the day while they sleep. At night, they are active and hunt for food. (Pierson and Rainey, 2004; Texas Parks and Wildlife Department, 2013)

How do they communicate with each other?

Western red bats primarily use echolocation to fly and find food at night. They have a specialized larynx that allows them to produce ultrasonic sounds that are emitted through their nose or mouth. The ultrasonic sound bounces off of objects and back to the large ears of the bat. By hearing these sounds, the bat can tell what is in its surroundings. This allows it to fly without running into objects, as well as detect any insects flying around. (Woodward, 2004)

What do they eat?

Western red bats eat insects, such as moths. They typically start hunting one to two hours after sunset, when nocturnal insects are active. These bats are often seen feeding in urban areas and rural towns around streetlights, where flying insects often gather. (Pierson and Rainey, 1998; Texas Parks and Wildlife Department, 2013)

  • Animal Foods
  • insects

What eats them and how do they avoid being eaten?

Western red bats are easy to prey on because they spend the day out in the open in trees and bushes. Western red bats have been recorded being preyed upon by Virginia opossums, and have been attacked and killed by birds on numerous occasions, with jays being the most common attackers. Other birds that prey upon these bats include falcons, owls, raptors in the genus Accipiter, and even roadrunners. Domestic cats have also been known to prey upon these bats. (Pierson and Rainey, 1998; Texas Parks and Wildlife Department, 2013)

What roles do they have in the ecosystem?

The main role of western red bats in their ecosystem is that they eat many insects. They eat enough insects every night that they are able to control the populations of certain insects such as moths and mosquitoes. (Pierson and Rainey, 1998)

Do they cause problems?

Many bat species can transmit diseases to humans, such as rabies. Dogs and cats can also get these diseases from bats. Luckily, western red bats are more likely to live in forests and rural areas, away from people, and they do not interact with humans much. (Woodward, 2004)

How do they interact with us?

Western red bats benefit humans by eating many insects that could be harmful to humans, such as mosquitoes. (Woodward, 2004)

  • Ways that people benefit from these animals:
  • controls pest population

Are they endangered?

Western red bats are not an endangered species.


Jenifer Lavender (author), Georgia Southern University, Michelle Cawthorn (editor), Georgia Southern University, Angela Miner (editor), Animal Diversity Web Staff.


Barbour, R., W. Davis. 1969. Bats of America. Lexington, Kentucky: The University of Kentucky Press.

Bucknell Univesity, 2008. "Lasiurus Blossevillii" (On-line). Wilson & Reeder’s Mammal Species of the World, Third Edition. Accessed April 22, 2013 at

Lesson and Garnot, 1997. "Western Red Bat, Lasiurus blossevillii" (On-line). Accessed April 22, 2013 at

McCracken, G., G. Wilkinson. 2000. Bat Mating Systems. Reproductive Biology of Bats, 12: 3-5. Accessed April 22, 2013 at

Pierson, E., W. Rainey. 2004. "Distribution and Status of Western Red Bats (Lasiurus blossevillii) in California" (On-line). State of California Resources Agency, Department of Fish and Game habitat Conservation Planning Branch.. Accessed April 22, 2013 at

Pierson, E., W. Rainey. 1998. "Terrestrial Mammal Species of Special Concern in California" (On-line). California Department of Fish and Game. Accessed April 22, 2013 at

Racey, P., S. Swift. 1995. Ecology, Evolution and Behavior of Bats. Oxford: Clarendon Press.

Texas Parks and Wildlife Department, 2013. "Western Red Bat (Lasiurus blossevillii)" (On-line). Texas Parks & Wildlife. Accessed April 22, 2013 at

Woodward, N. 2004. "Lasiurus borealis, Red Bat" (On-line). Accessed April 22, 2013 at

University of Michigan Museum of ZoologyNational Science Foundation

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Lavender, J. 2014. "Lasiurus blossevillii" (On-line), Animal Diversity Web. Accessed May 18, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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