Brandon Klüg, MSc, PhD Graduate Researcher, University of Regina
Dr. Cori Lausen, PhD, Birchdale Ecological Ltd.
Three species of bats are known to over-winter in Dinosaur Provincial Park. The rugged badlands landscape provides abundant underground habitat below the frost line, making the park an important hibernation site.
Hibernating bats allow their bodies to cool to a few degrees above freezing to save energy. However, they periodically wake up for short periods during winter and, especially in the prairies, actually fly during these breaks. We tracked bats flying in Dinosaur Park at temperatures as cold as -8°C! Flight uses up a great deal of stored fat, so there must be a good reason for this activity, possibly because bats need to drink. A heated water tank, nicknamed the "bat spa", operates in the park to test if bats drink during winter.
We know little about bat ecology during prairie winters. Therefore, it is important to determine where bats choose to roost, the condition of those roosts, and reasons for mid-winter arousals because these factors all affect winter survival.
Also affecting survival is white-nose syndrome (WNS), a recently introduced fungal disease devastating bat populations in eastern North America. WNS causes almost 100% mortality and has been reported in 22 states and 5 provinces. Over 5.5 million bats have died, leading to potentially severe ecological and economic costs. WNS appears to be spreading into the US mid-west, while in Canada it not yet appeared west of Lake Superior.
Our research aims to increase understanding of habitat selection and behaviour in bats over-wintering in prairie environments. Specifically, we are investigating characteristics of hibernacula and surrounding landscape; social behaviour, including clustering and roost switching; thermoregulatory patterns; and causes for mid-winter flight by free-ranging big brown bats.
So far, we have found that prairie bats use rock crevices as winter roosts, which are smaller, drier, and less thermally stable than known cave hibernacula. They also roost in smaller groups and do not move between sites throughout the winter. This may affect the potential risk of WNS as the fungus thrives in cold damp environments and often spreads by bat-to-bat contact. This means conditions in the prairies may not be overly conducive to the spread of WNS. However, we have found that bats show increased signs of dehydration as winter progresses, and dehydration has been linked to WNS-related mortality.
This project is a collaborative effort and major funding partners include the Alberta Conservation Association and Alberta Parks. In particular, Dinosaur Provincial Park provides considerable in-kind support. Wildlife Conservation Society Canada has contributed key financial and administrative support. The University of Regina (Dr. Mark Brigham), Birchdale Ecological, the University of Calgary, and the Natural Sciences and Engineering Research Council of Canada (NSERC) have provided additional funds, equipment, and support.
In addition, family and community members have come forward with many hours of volunteer time and donations. A complete list of sponsors is located at our bat monitoring station in the park's south campground loop.