By Mark F. Elderkin
Not long ago, little brown bats were the most common of six species of bats that occured in Nova Scotia, among the forty five species in Canada and the United States that are the most marvellous and efficient nocturnal insect eating machines in nature. Dr. Hugh Broders at St. Mary’s University in Nova Scotia, Dr. Don McAlpine in New Brunswick, Provincial Governments and Dr. Scott McBurney at the Canadian Cooperative Wildlife Health Centre in Prince Edward Island have been monitoring bats since the cold loving fungus, Geomyces destructans, commonly known as white nosed syndrome was first confirmed in New Brunswick in 2011. Results from monitoring bats in hibernacula in New Brunswick and Nova Scotia compiled in May 2013 confirm a 99 percent and 95 percent decline in these two provinces. When hundreds of bats started to be reported by the public flying in daytime as early as January that extended into May 2012 near Five Islands and Economy, then later near Scott’s Bay in Nova Scotia, it became all too clear that these diseased animals were coming from hibernation sites that were unknown to biologists. Desperate efforts to locate and document where the bats were coming from in 2012 and 2013, all failed.
Dr. Don McAlpine was the first to record the arrival of white-nose syndrome in Atlantic Canada, shown in a cave wearing disposable clothing coveralls and boots to reduce transmission between winter sites. Photo Copyright Karen Vanderwolf
Of the 45 species in North America, only 25 hibernate and it is these that are threatened by white-nose syndrome. Hibernation is a highly social event where hundreds-thousands of bats use the same underground sites such as caves or abandoned mines to conserve energy and survive the winter months. Sixteen hibernacula known in Nova Scotia are utilized by Little Brown bats, the largest of which had about 17,000 bats only a few years ago. In April 2013 the same cave had only 1,500 bats all of which appeared to be infected. A cave in New Brunswick that had over 6,000, and one in Nova Scotia that had 3,350 in the winter of 2010, now have next to none. While the centralized spatial nature of hibernation presents an elevated risk to populations by concentrating so many bats in a small area over an extended period, it also compounds the problem of quantifying the extent of geographic impact and effect. “How far away do the bats come from to get to the hibernacula?” and “How far do they go when they leave in the spring?” Answers to these questions are fundamental to our understanding the impacts that WNS has incurred in some jurisdictions that have had the disease for 3 or more years. It is equally important to our understanding the rate at which the disease will spread to uninfected regions across the continent. Little Brown bats in your attic or backyard in summer easily may travel between 150 and 500 kilometers to get there. After they leave hibernacula in mid-May, female bats form ‘nursery colonies’ to raise their young, while males form small ‘bachelor’ groups over summer. Both sexes reunite at hibernacula in late summer and mate into early winter.
Maps published on behalf of the International WNS working group, of which Canada is a partner with the United States, show where the disease outbreak has been confirmed using the county in the state and province as the scale of reference. While the ‘county’ scale applies sufficient precision in identifying where the disease was first documented, it does not illustrate the impacts that may extend for hundreds of kilometers beyond the county lines to include many adjacent counties in summering range where hibernating sites don’t even exist. Nor does it make any projection of where the disease will appear next. Whole states and provinces have been impacted in the wake of a rolling thunder moving with unprecedented rapidity and wrath that could soon envelope and swallow populations in the Canadian north and the west coast. Collapse of 7 species populations in eastern North America is only the tip of the iceberg and 18 other species on the continent are increasingly being put at risk as the disease continues to leap frog unabated. Not only have Little Brown Bats, Northern Long-eared bats and Tricolored disappeared at county scales – some species have been wiped out over the entire landscape in many states and provinces. How big is the actual area of impact in eastern North America and in Nova Scotia?
There is growing recognition in the bat conservation community in the United States and Canada that citizen science can play an important role in documenting the location and size of nursery colonies, hibernacula and the incidence of WNS. If we have learned anything here in Atlantic Canada in the wake of scourge from WNS, our recommendation to those jurisdictions that have not had WNS outbreaks, is that they need to act now. Understanding how many bats you have, where they are in the landscape through the seasons with basic biology of movements, is fundamental to understanding what maybe lost and the feasibility of effective recovery and management actions once the disease arrives. In my opinion there needs to be a North American wide initiative to gather together a snapshot on the state of knowledge through strategic and active participation of the public in collaboration with conservation groups across the continent. Social media could provide an important tool to accomplish this work.
For the twenty five species of hibernating bats that have been estimated to provide between 3.7 to 53 billion dollars in ecosystem services annually to the agricultural industry alone in North America, not including controls of forest insects and those like mosquitoes that are pests to humans – the response to an impending continental crisis for bats has been decidedly mixed. Since 2006, the Federal Government in the United States has invested over 16 million dollars to address the interstate coordination of monitoring and research on white-nose syndrome. In Canada, the Federal Government’s commitment to coordinate WNS diagnostics with provinces and universities through the Canadian Cooperative Wildlife Health Centre has been invaluable and timely for tracking the progress of the disease. Delays by the Federal Government in designating three species of bats as endangered under SARA, and lack of effective response following a recommendation for emergency listing by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) remain a concern. In the fall of 2012 the government announced that it would provide a total of 350 thousand dollars to create a WNS coordinator position for a three year term, which was welcome news. Field research, citizen science and stewardship work on bats in Canada remains inadequately funded.
In our fair province at least, we are no longer looking at an impending crisis in species conservation – it has arrived. We are now dealing with the embodiment of the term ‘endangered’ and basis for legal listing Little Brown Bat, Northern-long eared bat, and Tricolored bats, at least under our own Nova Scotia Endangered Species Act. Hopefully this will happen soon. If they are listed, a recovery team will need to be formed to consider next steps and approaches. You can help. This summer if you see bats, have them in your house, see them at your cottage, have a nursery colony in your belfry, bachelor bats in the woodshed – write down the date and time, numbers, behaviours and location. Keep your notes in a safe place you can refind! If you have a nursery colony in your roof line, wait for a warm summer evening, take your favourite beverage, family and friends with lawn chairs to watch and count bats as they emerge from the house. Don’t go in abandoned mines and caves that you may know of because you may spread white-nose fungus. If you do know where bats were hibernating this winter, or did hibernate based on past experience – this is very important information you should also keep record of for benefit of future conservation initiatives. Please record every bat you see this year!