At first glance one might imagine the Kuskanook Chalet in a coffee table book on modern architecture— a slant roof cabin perched on stilts at the edge of a pine forest. With its minimalist aesthetic and lake vista it seems set to score five stars on Airbnb. Except, small problem: there’s no door. At least not one for humans. This tiny chalet is designed and built for bats.
Building accommodation for bats may seem unusual, but this project is one of a handful that provides important habitat for species at risk in the Kootenays. Who benefits from these new builds? Bats and swallows. And according to Marcy Mahr, Kootenay Connect Manager for the Kootenay Conservation Program, their neighbours benefit too.
Bats and swallows are ‘aerial insectivores’ meaning they catch their food on the wing. Some people might think they’re a nuisance, but given how many mosquitoes they consume they’re actually great neighbours who efficiently clear the sky of insects – swallows working the day shift and bats the night shift.
Funded by Environment and Climate Change Canada, Kootenay Connect helps to sustain regional biodiversity by providing for the needs of federally listed species at risk. Although gobbling skeeters is a perk (bats eat their weight in insects every night, swallows dine on roughly 850 mosquitoes a day) it’s their role within the entire ecosystem that makes them a target species for Kootenay Connect and its partners.
Wildlife Conservation Society Canada (WCSC) is one such partner. When a maternal colony of bats were evicted from a nearby home, WCSC installed the Kuskanook Chalet just north of the Creston Valley Wildlife Management Area, one of Kootenay Connect’s focal areas. Evictions like these are a big deal: half of the 16 bat species in BC are threatened and habitat loss of any kind is a potential blow to the population.
“These long-lived mammals are creatures of habit,” says Dr. Cori Lausen, Director of Bat Conservation with WCSC, “if they can’t get into their familiar attic, sometimes they’ll actually hang on the outside of buildings.” Add the fact some female bats live up to 40 years and return every year to the same roost to raise a single pup, it’s no surprise WCSC stepped in with a new roost just 100 metres away from the bats’ original home.
But not all bats rely on a roof and four walls. Of 13 bat species in the Kootenays, only four regularly roost in buildings. The other nine species seek out large hollow trees and need loosening bark of old-growth forests to roost. Unfortunately, these types of trees can be difficult to find; forestry practices have left a scarcity of suitable mature trees. To address this loss WCSC has also been busy creating trees or tree-like roosts for bats.
Hang on, create a new tree? That’s right. By topping trees and notching crevices into the bark (some simulate a lightning strike) WCSC is able to make wildlife trees. As well, WCSC uses sheets of synthetic bark called BrandenBark™ to mimic loose bark found in mature forests. Of note, guano (aka bat poop) has shown many of these faux trees now have new bat residents, hurrah!
Why go to all of this effort to provide different roosting habitat? Bats can literally roast during hot spells. For a nursing mama and her pup, a roosting temperature of 42ºC is cozy but 44º can be lethal. As climate change pushes temperatures higher bats have been observed using a variety of roosts. Biologists now know bats need access to a variety of microclimates. Informally called the ‘Goldilocks approach’, one solution is to provide habitat that won’t leave bats stuck with a roost that’s either too hot or too cold: it needs to be juuust right.
Anyone who has watched a stream of little brown bats heading out for the evening may not believe they are endangered. But habitat loss paired with White Nose Syndrome (a disease caused by an invasive fungus that has devastated bat populations) and other threats have put bats into a highly precarious position. Of course, bats aren’t the only mosquito-eating species who could use a boost.
Throughout the Kootenays swallows can be seen gracefully feasting at high speed. Like bats, these birds are colony-dwelling and sight of them may give an impression of abundance. But a single colony is just a snapshot of the big picture. According to Birds Canada, over the last 40 years bank swallow populations declined by 98% and less than 2% of these swallows remain in Canada. Over the same time, barn swallow populations declined by 76%.
Statistics like these motivated biologist Rachel Darvill to start the Upper Columbia Swallow Habitat Enhancement Project (UCSHEP), a project administered by Wildsight Golden. To address the plight of these birds, Darvill and her team have spent the last three years monitoring and inventorying swallow colonies between Canal Flats and Edgewater. “It’s easy to disregard swallows or think they’re all the same,” says Darvill, highlighting the Columbia Valley is home to six different species, including bank and barn. “Many people don’t understand the challenges these swallows face, or know how critical the habitat in this region is.”
Why swallow numbers have dropped is still somewhat of a mystery. Although pesticide exposure, the massive decline of insects, and climate change are factors, loss of nesting habitat is one cause Darvill feels her project can affect. To that end, UCSHEP has recently put up five artificial nesting structures and dozens of nesting cups in key locations throughout the Columbia Valley.
Unbeknownst to many, swallows are protected by the Migratory Birds Convention Act making it illegal to damage, destroy or remove a nest without a permit. While some people find their chatter or droppings annoying, lending a roof to swallows is not just a stewardship gesture, it helps to ensure their long-term survival. Plus, their acrobatic performance is worth a pause. “They’re beautiful birds,” Darvill says, “such a marvel to watch.”
Both bats and swallows seek spots near water. Both need airy runways to take off and land. And because the Kootenays are home to threatened bats and swallows, both are front of mind for Kootenay Connect. Learning to coexist with these aerial insectivores not only means less mosquitoes, it supports the future of entire species. And with so many complementary habitat traits, cohabitation between these two seems ideal. This concept recently brought WCSC and UCSHEP together to build a dual species home in Parson. Wittily dubbed the ‘Parson AirBnB’ (for Bats n Birds) it’s an example of habitat innovation through partnership. Future monitoring will reveal the rating its new inhabitants give. Hopefully, a glowing five stars.
Cori Lausen with a spotted bat (Euderma maculatum); Northern myotis bat (Myotis septentrionalis); Rachel Darvill banding bank swallows (Riparia riparia); Rachel and volunteer doing mist netting at a bank swallow colony; Kooskanuk Chalet for bats, with Cori Lausen and building crew – photo by WCS Canada; four barn swallow chicks in nest (Hirundo rustica) – photo by Rachel Darvill; the ‘Parson AirBnB’ for bats and swallows – photo by WCS Canada.
