BAT CRISIS: WHITE-NOSE SYNDROME

On summer evenings bats provide an essential service, consuming bugs by the millions. A single bat can eat thousands of insects in one night. While bats are seldom seen and often feared, they play a role as essential to healthy ecosystems as the insect-eating songbirds we see during the day.

But in the eastern United States, something terrible is happening to them.

In the winter of 2006-2007, scientists documented a mysterious ailment in bats hibernating in caves and abandoned mines near Albany, New York. The obvious physical manifestation of the illness was a fuzzy white ring around the dying bats’ noses. Biologists thus dubbed the unknown affliction “white-nose syndrome” (also known as WNS). The white fuzz has been identified as a previously undescribed fungus in the genus Geomyces and has been aptly named Geomyces destructans for the devastating effect it has on hibernating bat populations.

While the fungus is the most visible symptom of this disease, it seems not to be the primary cause of death. Affected bats appear to be starving: Something about the syndrome causes the fat reserves they accumulate before entering hibernation to be depleted long before the winter is over. Since their insect prey is not available in these cold months, they simply run out of energy and die. Before dying, infected individuals exhibit unusual behavior. Bats have been seen in several northeastern states — in the dead of winter and in broad daylight — actively foraging outside the protective warmth of the caves.

Mortality rates between 70 and 90 percent are typical in affected hibernacula, though some colonies have been completely decimated; caves that once hosted hundreds or thousands of bats are now empty. What was a localized observation by scientists in upstate New York in 2007 is now recognized as an unprecedented threat to bats and confirmed in hibernacula in eleven states: Connecticut, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Tennessee, Vermont, Virginia, and West Virginia. Species currently known to be affected by white-nose syndrome are the little brown bat, big brown bat, northern long-eared bat, tricolored bat (formerly known as the eastern pipistrelle), eastern small-footed bat, and the federally listed endangered Indiana bat. Scientists believe that white-nose syndrome is primarily transmitted among individual bats as they gather to hibernate colonially, and may also be acquired from fungal spores present in the caves or mines where bats hibernate.

The origins of this syndrome are still unclear. There is speculation that the fungus was introduced by cavers with infected gear (a genetically similar fungus occurs in Europe, and G. destructans was recently confirmed on a bat in France) or that environmental toxins and other factors predisposed bats to infection by a pathogen that was already present. More than a million bats have died already, and hundreds of thousands more are likely to perish soon. Without action, certain populations — and perhaps even certain species — may disappear from the region forever.

OUR CAMPAIGN

Because white-nose syndrome is transmissible among caves by bats — and likely by humans, as well — the disease spreads rapidly and, if current rates of spread continue, could be devastating to bats already endangered by other factors.

For example, there are fewer than 10,000 endangered Virginia big-eared bats remaining. Further losses are unsustainable for this species. White-nose syndrome could spell the end for the Virginia big-eared bat if the species proves susceptible to it and the disease strikes one or more of its hibernacula.

According to the Fish and Wildlife Service’s records, 10 percent of the total population of Indiana bats overwinters in New York hibernacula. In the most recent recovery plan for this bat, the Service emphasized that populations in the northern portion of this species’ range — New York, Vermont, and Pennsylvania — had increased substantially over the past decade. But because of white-nose syndrome, the northeastern population of Indiana bat has declined 30 percent in two years. The bats are in a more precarious position than ever before. In January 2008, we wrote a letter to the Department of the Interior requesting the closure of caves and abandoned mines to public access to minimize the spread of white-nose syndrome. More than a year later, the Forest Service finally temporarily closed caves and abandoned mines across the eastern and southern regions. Since then, some states and private organizations have also issued cave closure orders, but this protection is far from complete.

In February of 2008, the Center petitioned the Fish and Wildlife Service, the National Park Service, the Forest Service, the secretary of the Army, the Corps of Engineers, the Tennessee Valley Authority, and the Federal Highway Administration to reevaluate federal projects where any endangered bat in the East might be harmed in light of the threat of white-nose syndrome. These federal agencies oversee highways, dams, and logging in bat habitat. In April 2008, as bats continued to die with no new protections on the horizon, we filed a notice of intent to sue the agencies. In 2009, after we joined with allies to file a protest against a plan to auction off oil and gas leases in a portion of West Virginia’s Monongahela National Forest — just a few miles away from a major hibernaculum for Virginia big-eared and Indiana bats — the Bureau withdrew the area from the lease sale.

But much more needs to be done to protect these sensitive species, so we joined 60 allies in sending a letter to members of Congress requesting increased funding for research on white-nose syndrome, and also sent a letter to then-Fish and Wildlife Service Director Sam Hamilton asking that prompt attention to white-nose syndrome be made a priority. Heeding our call, the Fish and Wildlife Service released a draft plan for management of the disease in September 2009, and additional strategic planning papers were posted in November. However, management actions to date have been largely limited to planning, and ongoing winter surveys show that major bat mortality is continuing throughout the eleven states in which the disease is currently confirmed.

Based on our growing concern about this crisis, Center filed two petitions in January 2010. The first requests that all caves and mines on federal lands be closed to protect bats and other cave fauna from the spread of the disease, and that formal advisories be issued to state agencies and private landholders recommending cave closures to protect hibernacula on these lands as well. The second is a petition to list two severely affected bat species, the eastern small-footed and northern long-eared bats, as threatened or endangered under the federal Endangered Species Act. Both species were rare and/or geographically restricted before the epidemic began, and both have suffered major population losses in the past three winters. Listing would confer significant protections for these species and their habitats, and improve their chances of surviving the horrific blow that white-nose syndrome has dealt them.