Summer is the season when property owners notice bats in their buildings. They may find guano (excrement) on the deck, hear bats in the walls, or smell a build-up of guano. The Kootenay Community Bat Project (KCBP), funded by the Columbia Basin Trust and the Columbia Valley Local Conservation Fund, has received hundreds of calls over the years with these issues. In many cases, landowners are happy to leave bats where they are. However, for landowners who would like to have bats move out of their buildings, now is the time to do something about it.
“With the decline of natural roost structures in the wild, such as large trees or undisturbed rock crevices, some bat species have adapted to use buildings for their roost sites,” says Juliet Craig, co-ordinating biologist for the KCBP. “Groups of related females can form large colonies called maternity roosts where they get together to have their one pup. These colonies may use attics, walls, chimneys, siding, barns, sheds and other structures.”
Under the BC Wildlife Act, it is illegal to exterminate or harm bats. In order to “get rid of bats”, the best strategy is to wait until they have left the building and seal up all the entry and exit points. However, in summer months, bat pups can become trapped inside.
In general, bats in the Kootenays leave buildings in the late summer or early fall. They use fall roost sites where they mate and then go into mines or caves to hibernate. Although there is a possibility that bats can use buildings over the winter, it is unusual.
“There are several approaches to managing bats in buildings,” continues Craig. “Some landowners don’t mind having bats and simply leave them be or clean up the guano once a year. Others want to ensure that the bats are no longer using the building. In those cases, this is the time of year to check that bats are no longer inside the roost and then work on sealing up all entry and exit points.”
One of the most important strategies in excluding bats from a building is to install a bat-house nearby. These wooden boxes comprised of various chambers provide the bats with an alternative habitat. They are less likely to be persistent in entering their old roost site in a building if they have somewhere else to roost.
Residents can build a bat-house this Saturday, November 29th at Wildsight Invermere’s Bat House Building Workshop at the Radium Seniors Hall at 4863 Stanley Street in Radium Hot Springs. All materials will be pre-cut so participants can put together a four-chambered bat-house. The first workshop runs from 9 to 11:30 a.m., a free talk on bat conservation will start at noon and go to 1p.m., and the second workshop goes from 2 to 4:30 p.m. The cost is $20 per box. Contact firstname.lastname@example.org or 250-341-6898 to register.
To find out more about how to do a bat eviction, bat-house plans, or bat biology, visit kootenaybats.com and download the “Frequently Asked Questions” booklet. Or call 1-855-9BC-BATS ext. 14.
Kootenay Community Bat Project