White-Nose Syndrome: Bats are going Batty
Bats dropping like flies? According to the U.S. Fish & Wildlife Service (FWS), a disease known as White-Nose Syndrome (WNS) has killed between 5.7 and 6.7 million bats as of January 17, 2012. The most recent update from the FWS confirms one of their biggest fears: the White-Nose Syndrome has crossed the Missouri River and is spreading west. But what is this devastating disease and why should humans care?
WNS was first cited in caves near Albany in New York in February 2006, according to the National Wildlife Health Center (NWHC). Since then, WNS has taken off and is now prevalent in 19 U.S. states and 4 Canadian provinces. As a result, bat populations in some areas have seen a decline in as much as 97%.
The disease is often visible as a white fungus on the bats’ noses and wings. The fungus is flesh-eating, chomping away at membranes on bats’ wings, tails, and ears. But what is extremely bizarre is that it appears to affect bats’ normal hibernating patterns. Normally, bats hibernate deep in caves (the sites are called hibernacula) and rest snugly for the winter. They use minimal amounts of energy and live off of only stored body fats. But now, bats affected with the disease have been sighted to roost near the entrance of the hibernacula and to fly during the day time. This puts the bats in great danger, as uses the much needed stored fats and puts them at greater risk of being attacked by predators, according to Tony Elliot, a scientist with the Missouri Department of Conservation, in an interview with NPR.
If you’ve seen The Happening (2008), maybe you’re thinking this suicide-causing disease will just outrun itself. However, on April 6, FWS stated in a press release, “Winter hibernacula surveys are wrapping up, but the disease is expected to continue to spread in the future.”
Why do we care?
Bats are excellent at pest control. According to Bat Conservation International, a single brown bat can eat 1,000 mosquito-sized insects in one hour. In central Texas, Mexican free-tailed bats eat the corn earworm moth, which attacks many different commercial plants. Mexican free-tailed bats from the Bracken Cave alone eat 200 tons of insects each summer night. According to Tony Elliot, gray bats in Missouri eat 540 tons of insects every year.
Bats are pollinators and seed-dispersers, since many of them drink plant nectar and eat fruits. In North American deserts, giant cacti and agave depend on bats for pollination. Commercial plants such as bananas, avocados, dates, figs, peaches, mangoes, durian, cloves, cashews, carob, and balsa wood also are heavily affected by bat pollination. When a forest is cleared for logging, bats can account for up to 95% of the first new growth, thanks to their seed disbursement.
Bat poop, or guano, is also important for cave ecosystems and is a rich natural fertilizer that is even mined is several countries.
According to FWS, to help alleviate the situation avoid entering hibernacula, which could further disturb hibernating bats, and report any unusual bat activities. If you do enter a cave, be sure to clean all caving gear thoroughly to prevent spreading the disease. However, with no known antidote, bat biologists expect White-Nose Syndrome to continue to spread throughout North America. With already over 6 million bats dead and some bat populations completely decimated, the future for North American bats looks bleak.