9 Types Of Bats In Connecticut (With Videos)

Types Of Bats In Connecticut
Fact Checked and Reviewed by: Mark Rhodes, Ph.D. - Wildlife Biologist
Dr. Mark Rhodes holds an MS in Fisheries and Wildlife along with a Ph.D. in Wildlife Ecology. He helps maintain our editorial standards of accuracy and quality. You can read more about Dr. Rhodes here.

Bats are truly fascinating critters and they are the only mammals capable of true flight. While there are more than 1,300 species of bat around the world, only nine of those bat species can be found in Connecticut.

So, what are the types of bats in Connecticut?

There are six species of cave bats in Connecticut, including big brown bats, little brown bats, eastern small-footed bats, northern long-eared bats, tri-colored bats, and Indiana bats. Connecticut is also home to three species of tree-roosting bats, including the hoary bat, eastern red bat, and silver-haired bat. 

Below, we’ll take a look at some interesting facts about these different species of bats, such as how to identify them, their habitats and habits, and more. I’ll also talk about threats to the population of bats in the state, as all of them are species of great concern and some are endangered.

Cave-Dwelling Types Of Bats In Connecticut

There are six species of bats that live in Connecticut’s caves and all six of them are considered to be “greatest conservation need” as part of Connecticut’s wildlife action plan. This action plan was implemented in 2005 in response to declining animal populations in the state, with a focus on preserving wildlife for the future.

One major threat to cave-dwelling bats in Connecticut is white nose syndrome (WNS). WNS is a fungus that thrives in cold temperatures, leaving bats most susceptible during hibernation. When it grows on bats skin, it disrupts hibernation and causes eventual dehydration, starvation, and death.

Big Brown Bat

Even though the big brown bat is the most common bat in the state, they’ve still suffered the devastating effects of WNS and are considered to have the greatest conservation need as a result. They are very important ecologically and for pest control, as big brown bats are primarily insectivores that can eat thousands of insects in a single night.

These bats have a big wingspan, standing only 4-5 inches tall and having wings that are 12-16 inches. They have black arms and wing membranes and their backs are covered in thick, brown fur that can be reddish brown, yellow brown, olive brown, or another slight variation. They roost in trees, caves, and manmade structures like barns and houses.

The biggest threats to the big brown bat population is WNS, pesticides, and predators. Pesticides kill insects and poison can be passed through breast milk, so bat pups can become poisoned when they nurse. Snakes, hawks, owls, and raccoons are all common predators of big brown bats.

Little Brown Bat

Little brown bats are slightly smaller than the previous bat, standing 2-4 inches tall and having a wingspan of 9-11 inches. While they are known as a cave-dwelling bat, they may also be found roosting in manmade structures like houses, garages, and barns, particularly when the weather is cooler.

The little brown bat shares a lot of similarities with the big brown bat, having varied colors of brown fur and a lighter-colored body. The greatest difference between the two species is their size, in addition to the little brown bat roosting in bigger colonies.

Little brown bats are also a species of greatest concern for conservation efforts, particularly because the population has seen a sharp decline as a result of WNS. They are considered endangered in Connecticut and have seen a 90% decline in population since 2008.

Eastern Small-Footed Bat

The eastern small-footed bat stands about two inches tall and has a wingspan of 8-10 inches. It is known for having a distinguishable black mask on its face, black arms and wingspan, and brown fur that has a gold sheen.

The eastern small-footed bat is considered to have an endangered status in Connecticut. However, it doesn’t share the same roosting habits as species like little brown bats, which have been devastated by WNS. Instead of hibernating in clusters, the eastern small-footed bat roosts individually in caves, mines, rock crevices, and under rocks.

Northern Long-Eared Bat

As the name suggests, northern long-eared bats are easily distinguishable by their long ears. They stand about 3-4 inches tall and have an 8-10 inch wingspan. Their fur isn’t a solid color, instead having a medium to dark brown color on their backside and a pale brown or tawny color on their belly.

Like many other types of bats in Connecticut, northern long-eared bats are an endangered species in the state. They are also federally threatened.

Like many other bat species, northern long-eared bats mate prior to the start of hibernation, something that is called delayed fertilization. Sperm is stored until after hibernation when the female bat ovulates and gets pregnant. In the summertime, many female bats gather in maternity colonies as they give birth to their pups.

Tri-Colored Bat

Tri-colored bats are also endangered in Connecticut. They stand about 3-3.5 inches tall and have a wingspan of 8-10 inches, though they are considered to be the smallest bat on this list.

Tri-colored bats get their name from the three distinct colors found in their fur, a darker color at the base and tip and a lighter color in the middle. They come in a variety of colors, including pale yellow and yellowish-orange, silvery-gray, chocolate brown, and black.

Tri-colored bats roost in a wide variety of places during the warmer months, including live and dead leaf clusters, recently dead deciduous trees, in pine needles, and in manmade structures like bridges, concrete bunkers, and porch roofs. Males roost singly, while females may roost in groups. They hibernate in caves and mines in the wintertime.

Indiana Bat

Indiana bats are known for their small, mouse-like ears and social nature. They stand just under 3.5 inches tall and can have a wingspan of up to 10 inches. The Indiana bats fur is chestnut brown to dark gray with a back that is lighter than their belly. They closely resemble the little brown bat, though their nose is lighter in color and their fur is softer to the touch.

The Indiana bat is endangered not just in Connecticut, but also federally. Despite being found in many states across the United States, their numbers are on sharp decline. This may be in part to their hibernation habits and the risk of white nose syndrome. Indiana bats hibernate in very large colonies and about 72% of the population was found in just four sites in three states.

Tree-Roosting Bats In Connecticut

The three tree-roosting bats in Connecticut are migratory species. This means that instead of returning to a cave to hibernate during the colder months, they are likely to fly to a warmer location.

Even though tree-roosting bats are not at a great risk of WNS, all three species are still considered species of special concern and having greatest conservation need among the wildlife of Connecticut. They face many other threats to their population as well.

Hoary Bat

Hoary bats are much larger than those mentioned so far, having a wingspan of almost 15 inches and standing 5-6 inches tall. They are also distinguishable by their fur, which is brown but has whitish-gray tips.

Hoary bats are solitary creatures that spend their days roosting in the leaves of deciduous and coniferous trees, often at the edges of meadows or other clearings with high insect populations. They can be found in Connecticut from spring until fall. After mating in the fall, female hoary bats migrate to the northern, eastern, and central parts of the United States, while males migrate to mountainous ranges in the west.

Eastern Red Bat

While the eastern red bat is still a species of special concern in Connecticut, it is the most common tree bat in the United States. They are known for their bright red color and may roost in deciduous trees near forest clearings, where it is easy to mistake them for dead leaves or pinecones.

While eastern red bats are only about three inches long, they can have a wingspan of up to 13 inches. They are more tolerant of cold than other bat species because of their long, silky fur that lets them withstand temperatures as low as 23 degrees Fahrenheit.

Silver-Haired Bat

The final type of bat that calls Connecticut home is the silver-haired bat. These bats are 3.5-4.5 inches long and have a wingspan of just under 12 inches. Silver-haired bats are aptly named because they are covered in black fur that has silver or white tips, which covers most of their body.

Silver-haired bats can be found in coniferous, deciduous, and boreal forests found all over the United States, with the exception of the southeastern and southwestern coasts. Often, they’re found roosting near bodies of water.

Like other tree-roosting bats, silver-haired bats are solitary creatures. It’s even been noted that the species is sexually segregated through the summer months, though they intermingle during breeding and migration seasons.

Final Word

There are nine types of bats in Connecticut, including three tree-roosting species and six cave-dwelling species. While cave-dwelling bats are known for their hibernation habits, they

There are many threats to bats in Connecticut. Cave-dwelling species are especially at risk of WNS fungus and bat populations have been on significant decline since it was discovered in 2007. Connecticut is also home to Indiana bats, which are considered endangered in the United States.

Hopefully, you’ve enjoyed learning about these fascinating creatures, and if you want to learn more about wildlife in Connecticut check out this article about their snake species population!