October 29

little brown bats suffering from white-nose syndrome Photo Credit: Nancy Heaslip, N.Y. Dept. of Environmental Conservation.

Science Fact

Common Bats Suddenly Endangered

In less than a decade, little brown bats, until recently one of the most common varieties of flying mammal in the United States, have become endangered. 5.5 million bats have died in the last decade.

That's because a virulent fungus, causing what is being called White-Nose Syndrome because the fuzzy white fungus is frequently found on bats' muzzles, has run rampant through hibernating bat populations across the Eastern U.S. Only discovered near Albany, N.Y., in 2006, the fungus has since spread across 25 states and five Canadian provinces, decimating 80-100 percent of the bats found at many of the sites where it has been identified.

The fungus (Geomyces destructans), which grows at temperatures below 68 degrees Fahrenheit, has devastated bat populations. White-Nose Syndrome causes bats to behave in unusual fashions during cold months when they would normally be hibernating—including flying outside during the day and clustering near the entrances of caves—before becoming sick and dying.

Scientists fear that up to 20 of the 45 bat species found in North America could be at risk. The White-Nose Syndrome has spread to at least six species so far. This is a long-term problem. Scientists predict little brown bat populations that once contained millions of bats could decrease to lower than 100,000 animals by 2018 and that some populations populations may not begin to increase again until around 2023. The problem will be particularly virulent in the East, where scientists predict that communities may dwindle to less than 1.5% of their original sizes.

You can learn more in this annotated paper from Science in the Classroom: A Tiny Fungus Is Causing Big Problems.

Bats are beneficial animals that save the U.S. agricultural industry an estimated $3 billion a year by eating insects that harm crops. They also eat insects like mosquitos that annoy humans and assist with plant pollination and seed dissemination.

Oct. 24–31 is National Bat Week. To learn more about this winged mammal, first check out the Science NetLinks tool Exploring Caves to learn more about bats' habitats and BioBlitz 2014: Nighttime Bat Walk to read about tracking bats in San Francisco's Golden Gate National Parks. You can also listen to this Science Update about how snakes sometimes team up to hunt bats in caves. Then explore these recommended resources to learn more about these nocturnal fliers:

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