Endangered Species

Midwest Region



Map of Region 3 Minnesota Wisconsin Michigan


Connect With Us

Facebook icon


Flickr icon




Twitter icon


YouTube icon



Buy Duck Stamps icon Endangered Species Day icon

Great Lake Restoration Initiative logo


Ozark big-eared bats

Maternity colony of Ozark big-eared bats in a cave at the Ozark Plateau National Wildlife Refuge.

Photo By USFWS; Richard Stark



Indiana Bat Calendar


<September - November>

Sun Mon Tue Wed Thu Fri Sat
October is National Arts and Humanities Month, a time to encourage Americans to explore new facets of the arts and humanities in their lives and to begin a lifelong habit of active participation in the arts and humanities. We’ll kick off bat facts this month with examples of bats in art.

Chinese art abounds with bats, adorning everything from fabrics to fine china. Chinese artists have long used a circle of five bats, called a wufu, to represent five blessings: health, long life, prosperity, love of virtue, and a tranquil natural death. The bats often are bright red, the color of joy.
Bats figure prominently in the art of many ancient cultures.  Mayan stories often feature bats as guardians of the underworld and a bat was the symbol of the ancient Mayan city of Copán.  An original Mayan sculpture of a bat can be seen in the Sculpture Museum of Copán.
A modern bat sculpture called “Nightwing” in Austin Texas is interesting not only for its bat shape but because it freely swivels with even a light breeze. The sculpture commemorates the largest urban bat colony in the country found beneath an Austin bridge.
How does an Indiana bat know that it’s time to migrate from summer habitat to its winter hibernaculum? Bats sense seasonal cues, such as declining day length and falling temperatures, but there is flexibility in response to these clues because the timing of migration varies from year-to-year depending on the weather, and varies among individual bats.
By now, most Indiana bats have arrived at their hibernaculum and are preparing for hibernation. In much of its range, the number of Indiana bats active at hibernacula increases through August and peaks in September and early October.
Upon arrival at a hibernaculum, Indiana bats "swarm," a behavior in which large numbers of bats fly in and out of cave entrances from dusk to dawn, even though few actually roost in the caves during the day.  Swarming continues for several weeks and during this time mating occurs.
After mating, adult females begin hibernation. Females store sperm from autumn mating throughout winter and fertilization is delayed until soon after spring emergence from hibernation. Some limited mating continues throughout winter and in spring as bats leave hibernation.

Male Indiana bats usually remain active outside hibernacula through mid-October or even later, especially at southern sites.  Males may extend their activity at the cave entrance during fall to take advantage of mating opportunities with late-arriving females.  A given male may mate with many females.
Fall is also an important time for Indiana bats to store sufficient fat to support energy requirements of hibernation.  During fall swarming, Indiana bats forage in the vicinity of the hibernaculum and gain weight, stored as fat, to sustain them until spring.
Bat movements in autumn often do not follow a simple linear pattern of migration from summer habitat to the hibernacula.  Instead, males, especially, may stop at multiple hibernacula during the fall swarming period.  In addition to mating, they may also be assessing the suitability of potential hibernation sites.
The age of reproductive maturity or first breeding is important in determining reproductive potential of a species, and is highly variable in bats.  Some female Indiana bats are sexually mature by the end of their first summer, although many will not mate until their second year.  Males are not sexually mature until their second year.   
Today marks the start of National Wildlife Refuge Week.  The nation’s 561 national wildlife refuges provide a network of habitats to benefit wildlife, provide unparalleled outdoor experiences for all Americans, and protect a healthy environment.  Visit a refuge this week many have special Refuge Week events.
National Wildlife Refuges provide habitat for more than 700 species of birds, 220 species of mammals, 250 reptile and amphibian species and more than 1,000 species of fish. More than 380 threatened or endangered plants or animals are protected on wildlife refuges.  At least 19 National Wildlife Refugesprovide habitat for the Indiana bat.
Trinity River National Wildlife Refuge in Texaswas established in 1994 to protect a remnant of the bottomland hardwood forest ecosystem along the Trinity River.  The Rafinesque's big-eared bat, a state-threatened species in Texas, is found on the refuge.  Watch this video for an up-close look at the bat and this beautiful refuge. 
Former military bunkers at Aroostook National Wildlife Refuge approximate conditions found in bat hibernacula. Research is being conducted to determine if bats can hibernate in these structures.  If so, they could become alternatives to natural hibernacula that are infected with white-nose syndrome, or an important location for WNS research.
Cypress Creek National Wildlife Refuge is located along the Cache River in Illinois. This watershed encompasses America's most northern cypress and tupelo swamp and has been listed as a U.S. National Natural Landmark. Many rare species, including the federally endangered Indiana bat, call the area home.  Scientists have radio tracked 37 Indiana bats on the refuge over the past 3 years.

Below the surface of Oklahoma's Ozark Plateau National Wildlife Refuge, an underground labyrinth carved by water and time is home to a myriad of animals living in dark passages hidden and undisturbed. A primary purpose of the refuge is to protect and recover federally-listed cave species including Ozark big-eared and gray bats. The total population of Ozark big-eared bats is less than 2,000 and the Refuge includes some of the most important habitat for it.
An exciting new monitoring program for bats is unfolding across the Southeast.  Thirty five National Wildlife Refuges and many other partners will be using acoustic monitoring devices mounted on vehicles .  Biologists drive predefined routes capturing and recording the ultrasonic echolocation calls of bats.
There are 45 bat species in the United States and many, like the Indiana bat, migrate between summer and winter quarters. However, four species may have longer migratory pathways than any other terrestrial mammal in the Northern Hemisphere. These four species are hoary bats, eastern and western red bats, and silver-haired bats.
Hoary bats, red bats and silver-haired bats are commonly referred to as "tree bats" because they roost in the foliage or trunks of trees year round, these species do not roost in caves.  These migration maps show just how far the hoary bat, red bat and silver-haired bat move.
Bat facts have highlighted many of the mysteries surrounding bat migration.  Bat fur may hold clues to solving some of these mysteries.  Isotopes in the hair of bats may reveal where the bat was when the hair grew and help elucidate seasonal movements of bats.
The hoary bat Lasiurus cinereus) is one of North America's most recognizable and striking bats. Its large size and rich color distinguish it from all other species. The genus name, Lasiurus, means “hairy tail” and hoary bats do indeed have a large, densely-furred tail .  As temperatures drop they can wrap the tail around their body to stay warm.
As temperatures drop and days grow shorter, chances to see bats silhouetted against the night sky diminish.  However, we will see plenty of bats in the news and on store shelves since bats abound during the Halloween season! During the week leading up to Halloween, we'll explore some of these images.
Vampires, those blood-sucking monsters of fiction and film, have "existed" since ancient times in the folklore and mythology of most cultures in Europe and elsewhere. But when did bats become associated with vampires? Read tomorrow's bat fact to find out.
Blood-lapping bats were observed by Spanish explorers in Central and South America and were given the label "vampire" because of the fact that, unlike all other bats, these live off the blood of their prey.  This may have been the source of the connection between vampires and bats that endures even today.
Dracula and bats are enduring and popular symbols during the Halloween season. In fact, Dracula is among the most popular Halloween costumes. If you are still looking for a costume, why not consider being a bat for the night, but spare the blood-dripping fangs! You can find lots of simple homemade bat costume ideas here for example.
Fortunately, not all characters associated with bats are as nefarious as vampires. The comic book superhero Batman first appeared in a DC Comics book in 1939 While sometimes portrayed with a "dark side" Batman has become a cultural icon and is a beloved crime fighter.
The character Bat Boy debuted in 1992 in the supermarket tabloid Weekly World News. Bat Boy, half human and half bat, evolved into a pop-culture icon and even became the subject of Bat Boy: The Musical, which premiered in 1997 and has since been produced in scores of productions throughout the world.
Lots of folks are thinking about bats during the Halloween season, so it's a great time to spread the good news about bats. Bats are shy, intelligent and very fascinating, use the information you’ve gained through bat facts to help others to appreciate bats. Visit Ranger Rick's Kids and BatWorld to see more about bats.
Happy Halloween! Treat yourself to some batty fun with this origami bat from a dollar bill.
Last updated: April 14, 2015