Another warning sign: U.S. bats are vanishing


North America’s bats are dying and the consequences may be profound.

Members of the order Chiroptera, the web-winged critters aren’t likely to evoke warm, fuzzy feelings in most folks, given their fictional association with vampires and demons.

But bats play a vital role in the natural ecology, both as insect predators and as pollinators.

According to Bat Conservation International:

White-nose Syndrome has devastated bat populations across the eastern United States during the past four years, causing “the most precipitous wildlife decline in the past century in North America,” according to biologists. And this relentless disease keeps spreading into new areas. BCI is working with agencies, organizations and individuals to understand and stop WNS and begin restoring these decimated bat populations.

Since White-nose Syndrome was discovered in a single New York cave in February 2006, more than a million hibernating bats of nine species have been killed by the disease in fourteen states.

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Mortality rates approaching 100 percent are reported at some sites. White-nose Syndrome has now moved into Canada, Maryland, Tennessee and Missouri. It threatens some of the largest hibernation caves for endangered Indiana myotis, gray myotis, and Virginia big-eared bats. Ultimately, bats across North America are at imminent risk.

Bruce Kennedy at DailyFinance notes the vital role the critters play in American agriculture:

You might be saying good riddance, but think again. Bats are the primary predator of night-flying insects. That not only includes pests like mosquitoes but also insects like corn earworm moths and cotton bollworms. In their caterpillar forms, those insects can destroy crops. A 2006 study of several counties in South-Central Texas concluded that the local bat population had an annual value of over $740,000 a year as a pest control — or up to 29% of the value of the local cotton crop.

A bat eats 60% to 100% of its body-weight in insects every day. Adams says one colony of Mexican free-tailed bats in Colorado’s San Luis Valley, an important agricultural region, “pulls about 100 metric tons of insects out of the air in a year.” And having bats in agricultural areas, he says, tends to move insects out of those areas, creating less need for dangerous and expensive pesticides.

And like honey bee colonies — which have also been facing massive die-offs in recent years — some bats are important pollinators and seed-distributors. Adams says bats are crucial to the reproduction of tropical fruits like mangos, papayas, figs and wild bananas. And in Arizona, bats are the primary pollinators for three large cactus species that support much of the region’s ecosystem.

The infestation has spread to Texas, where the state’s Department of Parks and Wildlife has produced this video on the infestation:

Here’s another video, this one from the U.S. Department of Fish and Wildlife:

Here’s more from Bruce Kennedy at Daily Finance:

“This is on a level unprecedented, certainly in mammals,” says Rick Adams, a biology professor at the University of Northern Colorado and a renowned bat expert. “A mass extinction event, a thousand times higher than anything we’ve seen. It’s going through [bat colonies] like wildfire, with 80% to 100% mortality.”

“The disease is absolutely devastating, it’s unprecedented,” says Mylea Bayless, a biologist with Austin, Texas-based Bat Conservation International. “It’s causing population declines in wildlife that we haven’t seen since the passenger pigeon.”

Bayless notes that bats have slow reproductive rates, usually giving birth to just one pup a year. So bat populations, she says, are going to be very slow to recover, “if they ever do recover.” The disease, adds Bayless, “is moving at a pace that’s astonishing, about 450 miles per year. In four short years, it’s now closer to the Pacific Ocean than it is to its point of origination in Albany, N.Y.”

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