It’s almost Halloween, a time to celebrate the ghoulies and ghosties and long-leggedy beasties and things that go bump in the night. One of the most enduring symbols of fright night is the silhouette of a bat, wings spread in a wide scallop, backlit by an orange glowing moon. But, please kiddies, don’t be frightened of these often misunderstood mammals (some of which actually do feed on blood). Bats play a critical role in the world’s ecosystem. In some African countries, bats are sacred animals thought to be the physical manifestation of souls. In much of Asia, bats are symbols of good luck.
Bats are not so revered here, despite their tremendous contribution to the public weal, and New Jersey’s bat population is dying off at an alarming rate.
This is the time of year many bats begin to hibernate. In New Jersey’s most populated hibernation spot – Hibernia Mine in Morris County – fewer than 1,700 of almost 30,000 bats survived last winter’s sleep, according to Mick Valent, Principal Zoologist for the New Jersey Division of Fish and Wildlife. Worse, Valent said, many survivors showed signs of infection with a fungus that is rapidly spreading across the country.
The fungus is called “white-nose syndrome” and is named for the whitish powder that appears on the nose, ears and wings of infected bats. This disease has killed an estimated 90 percent of bats in the state–and that’s very bad news, not just on Halloween.
Bats serve a vital role in the ecosystem as pollinators and seed-dispersers for countless plants. Without their pollination and seed-dispersing services, local ecosystems could gradually collapse as plants fail to provide food and cover for wildlife species. But perhaps their greatest contribution is in pest control. Bats consume about 3,000 insects per hour while feeding, and mosquitoes are a favorite food. Mosquitoes of course are carriers of some of the world’s worst diseases such as malaria, encephalitis and the West Nile virus. In New Jersey West Nile virus is a recognized problem which threatens to grow if the mosquito population is not controlled. Fewer bats mean more mosquitoes, more mosquitoes mean more illnesses, more illness means lost work and school.
Bats also like to eat many species of moths that damage agricultural products, vegetation and of course the clothing we all wear. One moth can potentially lay 1,000 eggs at a time, making them the scourge of New Jersey farmers and wool sweater-wearing New Jerseyans alike.
The obvious public policy alternative to the natural pest control bats provide is increased pesticide spraying. Spraying is expensive and carries with it health and environmental risks. Much of the cost of spraying is borne by New Jersey counties with some help from the NJ Department of Environmental Protection through grants, but that amount last year was only about $1 million for the state’s 21 counties to divide. The rest of the cost was borne by the counties.
Valent and other zoologists believe humans are to blame for the bats’ demise here; that fungal pathogens were introduced into American bat caves by visitors who previously entered European caves and carried the disease back on boots or equipment that wasn’t properly cleaned. While bats in Europe are not dying at the same alarming rate, scientists in the U.S. are working to figure out how to save their North American relatives. Valent is hopeful that common anti-fungal compounds might soon offer a cure.
So as you trick or treat, look to those black wings in the sky and beware the glint off of their sharp teeth. But be at least a little grateful and appreciate that those speedy little flashes zooming across the sky are important to us on more than just one night a year.