Signs of hope amidst the Northeast’s great bat recession
When trying to explain how white-nose syndrome (WNS) continues to affect Vermont’s cave bats, I sometimes compare it to the Great Depression [of the bat world].
After the stock market crash in 1929, the recession in the U.S. spread to other countries, just as WNS has spread from the northeastern U.S. into five Canadian provinces and continues to move south and west each winter into the 26 states where the disease or the causative fungus, Pseudogymnoascus destructans, has been found.
Despite fluctuations and hopes of recovery, the Great Depression lasted over a decade and was global in impact. If you think the 10 percent unemployment rate of the 2008 recession was bad, consider unemployment rates of 25 percent during the Great Depression. Now try to picture unemployment rates of 90 percent, the percentage of cave bats that have died in the Northeast from white-nose syndrome.
The crisis in our bat population is not a minor or momentary slump. After the initial shock of the 2008 recession wore off, I remembered people starting to ask “Is the economy recovering yet?” Although the Dow Jones Industrial Average eventually recovered, as economies continue to grow, many companies did not.
White-nose syndrome has not affected all bats equally. Some species, such as the big brown bat, appear to be doing OK, so I am confident these heroes of WNS will continue to grace the night sky. But for a few species now listed as endangered in Vermont, including the little brown, northern long-eared, and tri-colored bats, declines have been as devastating as bankruptcy and recovery is in no way guaranteed.
Endangered means that a species is at risk of extinction. Extinction means GONE FOREVER. Remember the passenger pigeon? There is no bailout option for extinction.
Yet even in the face of such drastic declines, we are beginning to see hope here in Vermont. Although bats were still found dying in our largest hibernation cave this winter, the initial 90 percent mortality rate has slowed significantly, and some individuals are surviving multiple winters at infected sites. Summer colonies of little brown bats that used to contain hundreds or even thousands of bats, described as “clouds of bats” by homeowners at dusk, are now completely vacant in the eastern part of the state.
Yet in the rich habitat of the Champlain Valley, small remnant colonies are hanging on. At one such site, a colony containing around 650 bats before WNS is now fighting to survive with less than 100 remaining.
Do these survivors have a genetically-based advantage that can be passed on to the next generation? We are cooperating with researchers from around the country to find out. Even if so, do Vermont’s six cave-dwelling species have enough of a population left to make it in the long run? Only time will tell. The northern long-eared bat has been proposed for listing as federally endangered due to 98 percent declines region-wide.
Every bat biologist out there would love to give a breaking story about bats recovering, but I cannot let my hopeful nature mislead you. Bats are still very much in trouble and they very much need our help. Although we don’t yet have a way to prevent the mass mortality caused by WNS, we can continue to use one of the most powerful human tools we have for conservation: education. There are a limited number of bat biologists and researchers working on the disease, but there are hundreds of thousands of people living in close proximity to bats in the U.S. alone. We can help protect the remaining 10 percent of our cave bats from other threats through education.
It’s amazing to see the look of fear on someone’s face change to empathy when they learn that most of the species affected by WNS have only one young per year and are more closely related to you and I than they are to mice. Now add in their economic value as agricultural and human pest eaters (bats can eat half their weight in insects per night) and soon you have everyone’s interest, not just wildlife enthusiasts. We can use education to minimize direct persecution, habitat loss, and the many other threats that bats face. Vermont’s cave bats have no hope of “recovering” in our lifetimes to the numbers we once saw, but we can make sure that each and every one counts and hope that is just enough to keep them around in the long run.
Thank you for helping. You really do make a difference.