CONTAC​T US

About Us

The BatCaver program is a partnership between bat researchers and cavers in western Canada.  

We are working to gain more insight into the use of our caves and mines by bats, particularly in winter when they are most at risk of White-nose Syndrome (WNS), a fungal disease of hibernating bats, caused by the fungus Pseudogymnoascus destructans (Pd).  Little research has been previously undertaken regarding cave bat ecology in BC and Alberta.  The goal of this program is to expand our knowledge by placing remote bat detectors (recording ultrasound produced by bats) and climate (temperature and relative humidity) dataloggers in caves and mines to monitor bat movements and gain knowledge as to the habitat characteristics of bat hibernacula in BC.  We are also taking fungal, soil, guano and bat DNA samples, with the assistance of the caving community, for analysis and species identification.  We collaborate with the Cave Biology Lab at Thompson Rivers University by providing samples that are assessed for useful properties, including some which appear to have antifungal properties against the Pd fungus that causes the disease. 

Since the introduction of WNS into eastern North America, bat populations are being decimated while the fungus that causes the disease is spreading westward.  It is imperative that we learn as much as we can about the wintering ecology of our cave bats in BC and Alberta in order to develop mitigation or prevention strategies for the disease.  BC is host to the highest diversity of bats in Canada, with at least 15 species, 13 of which are thought to overwinter in the province.  Of those that overwinter, more than half are thought to be vulnerable to WNS due to their tendency to hibernate in cool moist caves and mines.  Two of our western bat species have been reclassified as endangered (Northern Myotis and Little Brown Myotis) due to significant WNS-caused mortalities occurring in eastern Canadian hibernacula.

Where We Work

About Bats

Based on the fossil record, bats have existed for at least 53 million years.  Although small, they are very sophisticated creatures with life spans up to 40 years, making them the longest-lived mammals for their size. But they are also among the slowest reproducing mammals for their size, with most species and populations bearing only one young per year.  Bats of western Canada are all insectivores.  They feed on massive amounts of insects at night using their ultrasonic calls (mostly above the range of human hearing) to 'see' in the dark, much like sonar but more sophisticated.  They can catch their own weight in bugs in a single evening.  In the daytime, they will roost in rock crevices, trees and buildings where they will avoid daytime predators, and in the case of breeding females, select roosts that are sufficiently warm to raise young.  At night, they will hunt insects wherever they are found, including along lakes, streams, the ocean, cliffsides, on and around trees, streetlights (moths love streetlights!) and cave entrances.  At night, many bats will fly into caves to roost in the middle of the night, emerging for a final feed before dawn when they will retreat to their day roosts.  As the days get shorter, bats work overtime to feed and put on as much fat as possible before winter.  Many of our bat species will hibernate in caves and mines all winter while some of the larger bats migrate south.  When our bats hibernate, they are most vulnerable, as their dormant low energy state reduces their ability to fend off predators, and reduces physiological functions like immunity.

Where are hibernating bats found?

While research in western Canada is limited, we do know that long-term hibernating species tend to prefer quiet locations deep in caves and mines with high humidity, and relatively stable temperatures that approach but do not go below freezing. Most species appear to hibernate in proximity to water.  On the coast, many species hibernate in caves above 500 metres elevation due to cool stable internal temperatures, but there are many records of bats flying mid-winter in coastal areas, suggesting bats hibernate in other roosts such as rock crevices or even buildings at low elevations. Similarly, in the interior, many regions are suitable for hibernation, and a huge range of elevations are used. For example, the Townsend’s Big-eared Bat, which hibernates for short periods in caves close to sea level and in mines at low elevations across southern BC, is also found hibernating at elevations as high as 1500 metres in south-central BC.  The hibernation period in western Canada varies widely geographically and by species. For example, in West Kootenay, Yuma Myotis leave to hibernation as late as early December in places where there is little snowfall, and are sometimes back in their maternity roosts by late February although usually not until mid-late March. Little Brown Myotis in this area however typically leave maternity roosts by mid-late September and do not return back until mid-May. It is not known if this species is hibernating longer than Yuma Myotis, or if they use interim spring and fall roosts.

The longest-duration hibernators are thought to be the Little Brown Myotis, Long-legged Myotis, Northern Myotis, and Long-eared Myotis.  Often detected on bat detectors flying around low elevation habitats mid-winter in mild climates (e.g. West Kootenay, coastal areas, Okanagan, Boundary and Thompson regions) are California Myotis, Big Brown Bat, Silver-haired Bat and Townsend’s Big-eared Bat. Further research is needed, but to date, it has been shown that these species hibernate for periods of 1 - 8 weeks before emerging for a short (up to a few hours) flight. Why they fly mid-winter during sub-freezing temperatures is not well understood but during these flights some bats mate, some switch roosts, and presumably many drink water if available.

Based on what we know about the Pd fungus, long duration hibernators and those using highest humidity caves will be most vulnerable to WNS. We do not know how susceptible rock-crevice roosting bats will be as these hibernacula have not been well studied.The western bat species which hibernate for shorter periods and/or use drier hibernacula may prove less susceptible to WNS.

Want to know more about bats of BC? Stay tuned for a new updated version of the BC Bat Handbook, published by Royal BC Museum, anticipated in 2021.