Often feared and maligned, the bat’s reputation is undeserved. Regardless of myths, movies, and other misinformation, bats don’t attack people or fly in their hair. They aren’t “rats with wings”; they aren’t even related to the rodent family. Bats aren’t blind. Most bats can see as well as humans, and some can see in color and have adapted to low-light. They aren’t vampires and most have no interest in blood. Only the vampire bat subsists on blood, usually lapped from small cuts on livestock. Bats aren’t dirty animals – they actually spend much of their time grooming their fur so that it remains soft and silky, like household cats.
Bats fulfill important ecological and economical roles and are an essential part of each environment in which they live. Insect-eating bats, consuming as much as their own body weight every night, reduce the amount of pesticides farmers need to protect their crops. Bats consume mosquitos, which often carry deadly diseases such as West Nile Virus and malaria. Bats are vital pollinators, especially fruit bats. Many commercially valuable crops benefit from the pollination and seed dispersal by fruit bats. Pollination and seed dispersal by fruit bats is responsible for more than 95% rainforest regrowth, approximately 80 medicines and 450 commercial products.
Maybe it’s time to get to know more about your neighborhood bats, the species that are common to southwestern Pennsylvania, their current struggles against the deadly disease reducing their numbers, and how you can help the bats in your community. Pennsylvania is home to nine species of bat – the big brown, the little brown, the eastern red, hoary, the eastern small-footed, the northern long-eared, the silver-haired, the tricolored, and the Indiana bat. The evening bat can be found in Pennsylvania, also.
While not all of the bats in Pennsylvania are listed as threatened or endangered species, more species’ statuses are being changed from least concern to threatened or endangered. In 2019, three bat species were added to the Pennsylvania endangered species list by state Game Commissioners. These species – the little brown bat, the northern long-eared bat, and the tri-colored bat – joined the Indiana bat as endangered species in PA. Federally, the northern long-eared bat was listed as a threatened species in 2018. Of the species found in Pennsylvania, only the Indiana bat is listed as endangered by the U.S. Fish & Wildlife Service.
In addition to destruction of habitat, certain bat species are facing an often-fatal disease that is wiping colonies out in large numbers. White nose syndrome (WNS), a fungus attacking bats during hibernation, has been devastating bat populations since it was first detected in Pennsylvania during the 2008-2009 winter. WNS causes the bats to run out of energy mid-winter, prompting them to leave the cave early and usually causing them to die. Over the past decade, there has been a 98% decline in cave bat species. The Pennsylvania Game Commission (PGC) is one of the many institutions working to reduce the diseases effects on bats.
Conservation efforts are being made to help the reduced bat population. Significant hibernation sites are gated to minimize human disturbance. The PGC is currently working with colleagues on two management techniques that hope to reduce disease severity at the sites where they can be applied. “There are many funded projects trying to come up with a treatment to help,” shares Gregory Turner from the Bureau of Wildlife management, part of the Pennsylvania Game Commission. “Ours treats the environment and is showing some promise to help reduce disease and not impact any non-target species.”
The Appalachian Bat Count is a critical part in helping the PGC monitor population trends in summer bat colonies. The count helps document the location and size of surviving colonies, and allows the PGC to track reproduction timing, successful females, colony recruitment, and mortality events. Volunteers are asked to conduct a pre-volant count (before juveniles wean) around mid-May to June and then get a post-volant count in mid-July through August to capture the bulk of the juveniles and before the adult females leave. The count’s database is currently being updated. If you would like to participate, visit www.pgc.pa.gov/InformationResources/GetInvolved/Pages/AppalachianBatCount.aspx.
Want to take more action to help bats? “There is bill floating around congress called Recovering Americas Wildlife Act (RAWA). Constituents calling their reps and telling them to support this bill and get it moving forward would be good. This would be a game changer for non-game species to address their threats and help protect them,” Gregory adds.
Because most bats don’t live in caves year-round, and spend their summers roosting in trees and in dark buildings like barns, a bat house is an ideal way to provide habitats for local bats. The key when creating a bat house is to create a space that mimics their natural habitat. The main ways to do so are to keep the bat house narrow, paint it an appropriate color, seal the seams, and rough up the interior of the box. This satisfies their needs for tight spaces, warmth, and imitates a natural environment. Bat boxes can be built or purchased.
“People that have good habitat with bats or live near streams can put a good quality bat box up in a sunny location, particularly a location that gets sun early in morning. Boxes should be at least 10 feet above the ground level and be black for solar absorption. Putting several up gives the bats choices and some species like to move around,” says Gregory.
When placing a bat box, there are some considerations to keep in mind. You’ll need a location with lots of sun, 10 to 20 feet off the ground, 20 to 30 feet from the nearest trees, and with a nearby water source (if possible). A tall pole is a suitable place to mount a bat house, and the side of a building is even better. Bats prefer a house mounted on a building, and these houses offer a more consistent temperature. Buildings with wood, brick, and stone siding work the best; bat houses placed on buildings with metal siding rarely attract bats. Bats are less attracted to tree-mounted houses because there is often too much shade, the branches cause obstruction to exiting bats, and these houses are vulnerable to predation.
Because some species of bats prefer roosting in buildings, it is likely that you will come across a single bat, or even a colony at some point. The top priorities in removing bats from your home or other building are safety and humane removal. Improper removal or handling of protested species often results in strict penalties.
Single bats found in your home are commonly just a lost bat. Help the bat find an exit by opening doors and windows and closing interior doors. Remain quiet and turn off lights and electronics. If the bat does not leave, you can remove it. Because bats may carry disease, wear leather gloves and a long sleeve shirt to remain safe. Wait until the bat lands and cover it with a small container. Slip a piece of cardboard under the container and bat, while being careful not to catch any part of the bat between the layers. Flip the container and place in a quiet place until dark. If the container is airtight, create ventilation holes. You can add a piece of T-shirt fabric into the container for the bat to roost on. To release the bat, place the container in an elevated location, open the container, and turn it on its side. If the bat does not fly away, it may be sick or injured. Do not release bats during cold snap or deep freeze – call a rehabilitator to take the bat away.
Use care if you’ve found an injured or grounded bat, and do not directly handle it. Contact a bat rescue or rehabilitator to assist, such as the Humane Animal Rescue Wildlife Center in Verona, PA (412-345-7300 x500). If they are unavailable, you can reach out to the PA Game Commission for assistance.
Preventative measures can minimize the likelihood of bats entering your home and other buildings. To prevent single intruders, keep doors and windows screened, chimneys capped, and exterior attic and basement doors closed. If you have found a colony of bats in your home, you can hire professional bat removers or attempt to do so yourself, although the process is much more complicated than removing a single bat. For various methods on removing colonies, visit batcon.org.
Bats are an important part of their environment. They promote biodiversity and are responsible for the pollination, seed dispersal, and protection of crops and people from insects. They need our help – and we owe it to them to assist them and protect from the dangerous effects of disease and habitat decline. For more information on area bat species, conservation efforts, bats in your home, and directions on building your own bat box, visit the www.pgc.pa.gov/Wildlife/WildlifeSpecies/Bats/Pages/default.aspx.
Bats of Pennsylvania
The big brown bat (Eptesicus fuscus) reaches lengths of 4.1 to 4.8 inches with a wingspan of 12.1 to 12.9 inches. A dark brown bat, they are common across Pennsylvania, and known for their diverse habitats. They can be found in both the city and the country, in man-made and natural homes. Big brown bats are one of the last species to enter hibernation, waiting to hibernate until October, November and even December. During hibernation, they roost in caves, mines, buildings, and storm sewers, and emerge in March and April.
Distinct due to its bright rusty red fur – and a pair of large, pointed wings – the eastern red bat (Lasiurus borealis) reaches a length of 3.7 to 4.8 inches, with a wingspan of 11.3 to 12.9 inches. Flying at night, red bats migrate south in September or October and return in the spring. They are found roosting singly, except for females with young, in trees; they are rarely found in buildings and caves.
The largest bat in Pennsylvania, the hoary bat (Lasiurus cinereus) reaches lengths of 5.1 to 5.9 inches and has a 14.6-to-16.4-inch wingspan. The uncommon species has fur that is dark brown, tipped with white (hence the name hoary). They roost in trees, preferably conifers, approximately 12 to 40 feet above the ground, along forest edges, in woods, and around farmland. Hoary bats migrate in the winter and return in the spring.
Part of the vesper bat family, the evening bat (Nycticeius humeralis) is thought to be migratory, but studies suggest that some individuals may not migrate. The evening bat can be found throughout the eastern and midwestern United States and northeastern Mexico, roosting in small colonies in tree cavities and large colonies in man-made structures. During winter, they roost in their usual spaces and may even be found foraging on warm days. They are brown in color, and often mistaken for juvenile big brown bats. They grow to be about 4 inches in length, with an 11 inch wingspan. While it has been found in Pennsylvania, it is not common.
Until recently, the little brown bat (Myotis lucifigus) was considered one of the most common species of bat in America. Their glossy fur ranges from tan or reddish to dark brown, with black wings reaching 8.6 to 10.5 inches wide. Including their tail, they reach lengths of 3.1 to 3.7 inches. During hibernation, they leave their summer roosts of hollow trees, crevices, and dark buildings and move to tunnels, caves, and mine shafts. They emerge from hibernation in April or May and will often return to previous summer roosting sites.
One of the smallest species in North America is the eastern small-footed bat (Myotis leibii), also known as Leib’s bat. These small bats have an average length of 2.8 to 3.3 inches, with an average wingspan of 8.3 to 9.7 inches. Compared to other bats, they have a very small foot, with a distinct black mask stretching from ear tip to ear tip. Like the Indiana bat, they resemble the little brown bat, but with a golden tint to their fur. The bats begin hibernating in November and emerge in March. During hibernation, they can be found singly or in groups, inside cracks in walls, floors, and roofs.
The northern long-eared bat (Myotis septentrionalis) ranges throughout forested regions across Pennsylvania. They grow to be 3 to 3.7 inches in length, with a wingspan of 9 to 10.7 inches. Although similar to the little brown bat, northern long-eared bat are differentiated by their ears – narrower and longer – and a longer tail. They are also less commonly found than the little brown bat. These bats often share hibernation space with other similar bats, and can be found singly or in small groups, roosting in caves, attics, barns, tree cavities, and cliff crevices.
Formerly known as the eastern pipstrelle (Pipistrellus subflavus), the tri-colored bat (Perimyotis subflavus) was named for its distinct hair coloration: black at the base, yellow in the middle, and brown at the tips. The tri-color bat is one of the smallest bats in eastern North America and reaches a length of 2.9 to 3.5 inches, with a wingspan of 8.1 to 10,1 inches. They hibernate from September through April/May, deep inside caves. During the summer, they roost in open woods, near water, rock, or cliff crevices, as well as buildings and caves.
Resembling the little brown bat, the Indiana bat (Myotis sodalist), has a pinkish cast to its brown fur, making them appear a purple-brown color. This small bat reaches lengths of 2.9 to 3.7 inches, with a wingspan of 9.4 to 10.3 inches. Not commonly found in buildings, Indiana bats roost in trees during the summer; during the winter, the majority of the species hibernate in specific caves located in Missouri, Kentucky, Indiana, and Illinois. Approximately a dozen Indiana bat wintering sites have been found in Pennsylvania, located in caves, abandoned mines, and railroad tunnels.