Bats have a reputation for being “spooky,” which is why they are seen so often in Halloween costumes and decorations.
But these flying mammals, creatures of the night, are more misunderstood than mysterious. Other than vampire bats that lap up the blood of monkeys and livestock in the tropics, they do not want to suck your blood … but they will voraciously gobble thousands of insects a night.
A recent study found that bats may be worth as much as $53 billion a year to the U.S. agriculture industry, saving crops from a multitude of insects and reducing the need for chemical pesticides.
Far scarier than having bats swooping and diving around your yard at night is the prospect of not having them around to provide free and natural pest control.
A fungal disease known as White-nose Syndrome has swept through bat populations in the United States and Canada during the past six years, devastating many species. New Jersey is home to nine bat species — six residents and three migrants — and hardest hit have been little brown bats, once the state’s most abundant species.
According to the state’s Endangered and Nongame Species Program, more than 95 percent of the state’s little brown bats have perished from white-nose.
The state’s biggest bat cave, also known as a hibernaculum, is the abandoned Hibernia Mine in Morris County. In 2009, the first year White-nose Syndrome hit, experts counted more than 26,400 little brown bats at Hibernia. By this year the number was down to 471 — a greater than 98 percent drop.
White-nose Syndrome is named for the fuzzy white fungus that appears on the muzzles, ears and wing membranes of affected bats.
When bats hibernate, their body temperature drops and heartbeats slow to conserve energy. White-nose disrupts hibernation, causing bats to fly outside, burning precious fat reserves. Without enough energy to carry them through the winter, the bats die of starvation and dehydration. The fungus also tatters their delicate wing membranes, so infected bats that survive hibernation may be unable to fly and hunt for food in the spring. Migratory bats have not been seriously affected by white-nose because they do not winter in cold northern places where the fungus is found. Of New Jersey’s resident bats, only the big brown bats seem to be unaffected by white-nose. In fact, state bat surveys show the population of big brown bats has increased by 50 percent in the last few years.
“This is what is known as ecological release from competition,” said Dr. Emile De- Vito, the New Jersey Conservation Foundation’s staff biologist.
Without competition for food and territory, he explained, the big brown bat populations expand and fill the void. This is a trick, not a treat, should little brown bat or the federally endangered Indiana bat populations begin to recover. If the bat habitat niche becomes dominated by one species, that could hinder recovery of tiny populations of rare species.
The state is trying to figure out ways to help bats, especially little browns, survive White-nose Syndrome. They are using volunteers to count bats at summer maternity colonies, identifying bat survival trends through acoustic surveys, nursing infected bats back to health and even trying to assist with breeding. Initial research shows that survival rates in remnant little brown bat populations may be improving.
Perhaps researchers can find ways to help restore their populations, but it will not be easy. Bats are among the slowest reproducing animals on the planet, with most species giving birth to only one “pup” per year.
You can help by being aware of bats that may be living on your property and protecting these beneficial creatures.
If you discover bats in your attic or barn, do not harm them or seal off openings. Consult a wildlife professional and consider putting up a bat house to provide them an alternative place to roost during the summer. The Conserve Wildlife Foundation of New Jersey provides free bat houses to homeowners.
Michele S. Byers is the executive director of the New Jersey Conservation Foundation.