White-nose syndrome and bat conservation
By Dr. Brock Fenton
Department of Biology, UWO
For many years bat biologists with the New York State Department of Environmental Conservation have made annual counts of hibernating bats to track population trends within their jurisdiction. In 2007 these visits to hibernation sites revealed piles of dead bats. The situation got progressively worse during during the winters of 2008 and 2009. Although there has been no sign of mortality associated with WNS in summer roosts, the numbers of little brown bats (Myotis lucifugus) in some roosts as declined significantly, and in some cases entire colonies have disappeared.
In the United States, WNS has become a strong focus for those concerned about bat conservation. Various federal and state agencies have invested in and continue to support work designed to curb the spread of WNS and to protect bats from it. In Canada, there is now ongoing monitoring of populations of hibernating bats at some sites, and close collaboration with our American colleagues.
But there is no obvious quick fix to the problem. At the 2008 meeting of the North American Symposium on Bat Research (in Scranton, Pennsylvania), Al Hicks, one of the leading researchers in this area, made a dire prediction. Unless something changes, Al expects that little brown bats will be extirpated in northeastern North America within 10 years.
In Ontario, bat biologists are working closely with colleagues from the Ontario Ministry of Natural Resources in support of efforts to monitor what is happening to our bat populations. We also are staying out of hibernation sites for two good reasons. First, people entering these sites (caves and abandoned mines) inevitably disturb bats and push them to the edges of their energetic stores. Second, people going from site to site, may be involved in the spread of the WNS fungus, so the Ontario Ministry of Natural Resources has developed protocols to minimize site-to-site contamination by people.
The good news is that the fungus causing WNS does not appear to survive alone in caves and mines. The bad news is that the syndrome continues to spread and we can do little more than monitor and watch.
We may have to come to grips with the notion of a world without little brown bats. This is the most common and abundant species in Ontario, although mainly in the countryside and rural areas rather than cities. If we lose them, the situation may provide a graphic demonstration of the ecosystem service that little brown bats have been providing – as predators of insects if nothing else.