Center for Biological Diversity

For Immediate Release, September 23, 2014

Contact:   Mollie  Matteson, (802) 318-1487
Katie Gillies, Bat Conservation International, (775) 934-2544
Amey Owen, Animal Welfare Institute, (202) 446-2128

Report on Vanishing Species: Bat Once Common Across Eastern United States Among
10 Plants and Animals on Fast Track to Extinction

Flitting of Bats on Summer Evenings May Vanish Into Past If Swift Action Not Taken

RICHMOND, Vt.— The little brown bat is highlighted in a report released today by the Endangered Species Coalition recognizing 10 disappearing species from around the country that could be lost in our lifetime. The bat was once common across the eastern United States but today is on the brink of extinction, with hibernating bat colonies in northeastern and mid-Atlantic states having declined by more than 90 percent. The primary cause of the decline, a fungal disease known as white-nose syndrome, continues to spread across the continent.


Today’s report, Vanishing: Ten American Species Our Children May Never See, chronicles the bat and nine other once-common species that are now threatened with extinction.  The Center, along with the Animal Welfare Institute and Bat Conservation International, nominated little brown bats for the report.

“Bats successfully evolved over millions of years as one of the most diverse and ecologically important group of mammals on Earth, but now the little brown bat is one of several bat species facing extinction,” said Mollie Matteson, a senior scientist at the Center for Biological Diversity. “It will be very sad indeed if children of the future never have the chance to watch the nighttime acrobatics of bats hunting for insects. Since it was almost certainly people who brought the fungus that causes white-nose syndrome from Europe, it’s our responsibility to undo that damage, too, and save these bats from disappearing forever."

The Center, Bat Conservation International and other groups requested that the U.S. Fish and Wildlife Service confer emergency federal protection on the little brown bat in 2010. The species is threatened throughout its range by a variety of factors, but foremost by the white-nose fungus, new to North America, that wipes out hibernating bats. Probably introduced from Europe by people traveling between cave environments on the two continents, the disease first appeared here in a cave adjoining a popular tourist cave that receives over 200,000 visitors each year.

Other threats to the little brown bat include loss of summer roosting and foraging habitat, cave disturbance by people, and wind-energy operations lacking wildlife-protection strategies. 

"This report calls attention to the fact that species are vanishing before our eyes,” said Cathy Liss, president of the Animal Welfare Institute. “By including this oft-overlooked bat species, which despite its small size is of enormous ecological and economic value, the Endangered Species Coalition is building much-needed awareness that this animal is in grave danger of extinction.”

The other species highlighted in today’s report are the monarch butterfly, mountain yellow-legged frog, polar bear, great white shark, rusty patched bumblebee, whitebark pine, North Pacific right whale, greater sage grouse and Snake River sockeye salmon.

In addition to exploring the causes of the dramatic population declines of the once-common species, today’s report identifies everyday actions that people can take to help slow their disappearance. The report can be viewed and downloaded from the website

Little Brown Bat Background
Little brown bats are small, night-flying mammals weighing about one-quarter of an ounce. They subsist exclusively on insects. They often roost colonially, sometimes in house attics and barn lofts, and were once one of the most common bats in the eastern United States. Little brown bats range in color from light tan to dark brown. Compared to similar bat species, they have small ears. Like other bats, they navigate in the dark by a type of sonar called echo-location. For such a small mammal, the little brown bat lives a long time. The oldest known was 31 years. Females give birth to one pup per year, which they keep safe in “maternity colonies” while the mother bats go out to feed. A little brown bat can eat at least half its body weight in insects each night.

In winter little brown bats retreat to caves and mines where temperatures are stable and cool, but not freezing. They lower their body temperatures to nearly the ambient temperature as they go into a period of hibernation, and during this time, they survive only on the body fat they have managed to accumulate during the summer. This is a vulnerable period when any disturbance, including cave visitation by people, can rouse the bats and force them to expend needed energy, resulting in starvation.

White-nose syndrome was first documented in North American bats in upstate New York in 2006. Since that time, the disease has spread to 25 states and five Canadian provinces. Mortality rates in affected bat colonies have ranged as high as 100 percent, and the U.S. Fish and Wildlife Service estimated in 2012 that nearly 7 million bats had died. The disease spreads primarily through bat-to-bat contact and cave-to-bat contact. However, people may also spread the disease-causing fungus inadvertently on clothing and gear.

Bats provide a valuable service to people by keeping a check on insect populations, including moths, beetles, and other bugs that eat crop plants and trees grown for timber. Scientists estimate that nationwide, bats provide $22 billion of pest control services to farmers every year.

In 2010 the Center for Biological Diversity, Bat Conservation International and other groups and individual bat biologists asked the Fish and Wildlife Service to consider an emergency listing of the little brown bat under the Endangered Species Act. Scientists had projected a 99 percent likelihood of regional extinction of the little brown bat in the Northeast by 2026. Because no formal petition was filed, the Service was not bound to a particular timeline for response, and the agency has still not issued a status assessment or recommendation on protection for the species.

For today’s report Endangered Species Coalition member groups nominated wildlife species and a committee of scientists decided which species should be included. The coalition produces a “Top 10” report annually, focusing on a different theme each year. Previous years’ reports are available on the coalition’s website.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 775,000 members and online activists dedicated to the protection of endangered species and wild places.

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