
Before she began working with bats ten years ago, Heather Gates hadn’t paid much attention to them. Today, she is fascinated by these remarkable animals. As the primary predators of night-flying insects, bats are a vital component of local ecosystems as well as being very important for agriculture. Heather conducts bat research and stewardship across the Columbia Basin as part of her work for Wildlife Conservation Society Canada (WCSC), based in the Kaslo office.
One of Heather’s key projects is WCSC’s Tree Enhancement and Roost Mitigation project, which focuses on creating alternative roosts for tree-roosting bats, utilizing BrandenBark™ (a synthetic material used to mimic natural bark and create artificial roosts for bats) and chainsaw cuts. Most of the 16 confirmed bat species in the province rely on trees for their roosts.
Heather clarifies that “young trees don’t cut it. They need the cracks, crevices and sluffing bark of old growth. Because old growth trees are lacking, we are taking young trees and essentially creating snags out of them, so either wrapping them with BrandenBark™ or putting chainsaw cuts in them to create crevices and cracks.”
Modified roosts are monitored using guano traps, to identify bat species using genetic analysis of their feces, and acoustic roost loggers and microclimate monitors.
“The results of the guano trap monitoring have confirmed that seven, probably eight, species of bats are using the BrandenBark™ and the chainsaw-created roosts. Some species do seem to prefer the chainsaw cuts over the BrandenBark™. They are very particular about what they like.”
Modified tree roosts are important for bat habitat to support maternity colonies of females and their pups, and because they provide a variety of microclimate opportunities, so bats are less likely to overheat.
Bat boxes only appeal to a couple of local species: Little Brown Myotis and Yuma Myotis. As the climate gets hotter, bat boxes are becoming less ideal, as overheating is becoming more of an issue.
“If people want to put up bat boxes, they should put them up in clusters of three, in different locations in terms of solar exposure and aspect.” Heather explains. “For example, one in full sun, one that is a little more dappled, and one that has more shade, so the bats have microclimate options.”
As well as modifying trees, WCSC has been experimenting with using cedar poles. The first pilot poles were installed in 2020 near Golden; one using BrandenBark™ and one using natural Douglas fir bark. The poles were a success, and since then, Heather and the WCSC team have installed 183 roosts in trees and poles at 30 different locations throughout the Columbia Basin.
“The funding through Kootenay Connect Priority Places and the Local Conservation Funds (in the Columbia Valley and the Regional District of Central Kootenay), along with other funders, has definitely brought this vision to life and allowed us to create these important roosts. It has been amazing to be able to go back after a year and find they are already being used. Some are used as maternity roosts in the first spring after installation!”
Heather also says it’s been great to be able to partner with land trusts such as the Nature Conservancy of Canada, The Nature Trust of BC, and The Land Conservancy of BC as well as enhance roosts on other conservation lands throughout the Kootenays, in several provincial parks, and on public land.
“The Kootenays are a hub of bat knowledge and research! Our work on roost structures complements the work of the Kootenay Community Bat Project (initiated in 2004) which focuses on working with landowners who have bat roosts in buildings, raising awareness about the importance of bats, and engaging citizen scientists. I don’t know how people in other areas feel about bats, but I would say that 98% of people that I talk to in the region tell me they really like bats. I hope this appreciation is more widespread than the Kootenays.”
If you have questions about bats on your property, contact the Kootenay Community Bat Project.
The current most serious threat to bats in BC the loss of habitat through forest harvesting and other industry and development. White-nose syndrome, a disease caused by a fungus that causes bats to wake up from hibernation and become active, so they burn through their stored fat and starve to death, could present an even larger threat once it arrives.
“We haven’t seen White-nose syndrome here yet,” Heather clarifies. “The closest detection of the fungus was near Grand Forks, but the actual disease hasn’t been detected in BC. We anticipate that it is coming.”
Because the fungus thrives in cool, damp conditions that mirror those bats seek for hibernation, species that hibernate locally through the winter are prone to this syndrome, which are most of the bat species in this area including – but not limited to – California Myotis, Townsend’s Big-eared bat, Little Brown Myotis, as well as local populations of Silver-haired bats.
In regions where bats have died off due to White-nose syndrome, pesticide use has increased, which has resulted in the infant mortality rate of people going up 8%. “This is really shocking and shows how much we need bats.”
Heather grew up near Abbotsford, where her family operated a commercial greenhouse. Her post-secondary education was focused on plants and botany, and after moving to the West Kootenay, she worked as Head Grower at the PRT nursery in Harrop. She describes her foray into working with bats as being ‘in the right place at the right time’, as she was ready for a new opportunity when she heard that Dr. Cori Lausen with WSCS was looking for a field assistant. “I basically learned everything I know about bats from Cori.”
Heather explains the next steps for WCSC’s Tree Enhancement and Roost Mitigation project: “to try to produce our own types of bark-mimic sheets which are affordable and accessible to landowners, with a few options of various sizes and types of bark. We want to be able to provide an alternative to bat boxes, and we are working with Selkirk College on this, to have it locally produced.”
Photos: Heather with a spotted bat; Heather with the arborists and a sheet of BrandenBark™: photo by Lorna Visser.