Take a Bat Walk

Bats are one of the most interesting and unique mammals in the world.  There are over 1,000 different species of bats worldwide and make up about a quarter of all mammal species.  They are important pollinators of such plants as mango, banana, and cashews.  Fruit-eating bats are very important in the rain forest.  They spread over half of the initial seeds in a cleared rain forest.  Finally, in our own backyards, bats are the primary predators of night-flying insects.

Bat Walks During the Day

Most bats hide from predators during the day while they sleep, and thus can be very difficult to locate.  Point out places that bats might live and discuss some of these aspects:

Some bats are solitary (live alone) and use camouflage to keep them safe.  This disguise usually takes the form of blending in with the color of the tree, for example the hoary bat often roosts in evergreen trees and uses its brown, white, and yellow coloration to hang unnoticed.  Other solitary bats, like the red bat, hang in maple trees from one foot, curl up in a ball, and pull their furry tail membrane over their head to look like a leaf.   Bats that live in colonies (a group of bats) may live in a barn, house, dead or dying tree, rock crevice, cave, cavern, or in expansion joints beneath a bridge. 

When looking around the city for bats, point out church bell towers, shutters on houses, attic vents, on the underside of bridges, and cracks in buildings.  Bats will usually be up high, in a warm, dry, dark location where they await dusk.  When looking for bats in a natural setting, point out any dead or dying trees (bats often live in dead trees, especially those with loose and peeling bark and any cavities), live trees (especially evergreen, maple, and sycamore trees), rock crevices, caves, shrubs, and holes in cacti.  During fall and winter, some bats have been known to sleep under fallen leaves on the ground for warmth. 

Bat Walks at Dusk

If you are going to take a walk at night, make sure you are familiar with the area and inform the participants of any potential hazards. Consider limiting the size of the group to ensure a pleasant experience.  If there is a good possibility of seeing bats up close, ensure that everyone knows not to touch any bat.  Bats are timid creatures, but will bite in self-defense.  Prior to the night walk, recommend that the attendees wear suitably warm and weatherproof clothing and shoes, and make sure to bring a flashlight (red filter if available) and bug spray.  Arrive just prior to sunset and be on the lookout for bats flying about 15 minutes after the sun goes down.  The best time to see bats is on a warm summer night when there a lots of flying insects.  In the Canada and northern United States, bats hibernate (sleep through the winter) when the temperatures go below freezing.  Bats can be seen year round in southern parts of the United States and into Mexico. 

Dusk is the best time to look for bats because it’s not yet too dark to see, but dark enough for bats to leave their roosts.  In the city, look for bats hunting around lights on streets, playgrounds, football or baseball stadiums, or parking lots.  In natural settings, look for bats near open water such as lakes, rivers, and ponds. Stand so the water is between you and the sunset. The lake will reflect the sky and light up the bats.  Other areas to see bats flying around are in fields, wetlands, prairies, and at the edge of woods and forests.  If you are lucky enough to live near an existing colony, you can go at dusk with a blanket and video camera to watch the emergence.  Some of the best places to find large numbers of bats are caves, caverns, mines, bridges, barns, and bat houses.  Often, simply find swarms of insects and bats will soon be there. 

If you own or can borrow a bat detector, it is by far the best way to tell if bats are flying in the area.  Bat detectors pick up bat echolocation calls as the bats fly around foraging for insects.  The microphone inside the bat detector is capable of detecting high frequency sounds that a human can’t hear.  The detector then converts the calls into a sound that we do hear. 

Spotting a Bat

Record the time, place, and location of the discovery.  What is the bat doing, how is it flying, are other bats flying in the area, how does it catch its food?  Keep a journal of your bat observations.  You may also want to try to take a picture, video, or audio recording.  Make sure not to shine a flashlight directly at the bat as it is flying.  It may change its foraging behavior or be easy prey for predators.  Be on the lookout for bat predators.  Hawks, owls, and snakes are a few animals that prey on bats.  Birds of prey can often been seen in the sky or on a branch waiting to swoop down and grab a bat.  Other known predators include raccoons, opossums, and cats. 

Make sure it is a bat and not a bird seen flying.  Some birds, like swallows and martins, have a similar silhouette as bats and will be out at twilight hunting for insects.  One thing to know is that birds usually glide between flapping, with wings close to their bodies.  Bats rarely glide and if they do, they usually have their wings extended during flight.  Also, birds usually fly in a smooth, straight direction.  Bats generally have erratic, swooping flight.  In addition, see if the animal is going into a roost or coming out of a roost at dusk.  Birds will be heading in at sunset and bats will be emerging.  Finally, most bats in the North America are much smaller than their nocturnal bird counterparts such as nighthawks and owls. 

Bat Walks with a Naturalist

Check with your local nature center, museum, zoo, or other educational institution to see if a bat expert would be willing to lead a bat walk.  People who study bats often carry bat detectors that translate bat echolocation (sonar) into sounds humans can hear. 

For More Information

You may find it helpful to pick up a copy of the “Stokes Beginner’s Guide to Bats.”  This first of its kind field guide to bats of the United States and Canada provides information about individual species.  Specifics about roosting, flight, migration and more can be found in this book.  In addition, after you go on several bat walks, you may want to build or purchase your own bat detector.  

© 2012 Organization for Bat Conservation