Photo courtesy of Juliet Craig
Townsend's Bats
Cluster of the rare Townsend’s big-eared bats in a house.
Bats play an important role in our environment, consuming large amounts of insects, some of which are costly agricultural and forest pests in their larval and adult flying forms. A healthy bat population is definitely a big plus for agricultural producers.
There are at least sixteen species of bats found in British Columbia and although most species roost in caves, cliffs and trees, six species like to roost in man-made structures such as houses, bridges, and barns.
Male bats need somewhere to roost during the day while female bats need habitat suitable for giving birth and rearing young. Temporary daytime roosts can include any outside wall covered by a roof, trees, patio umbrellas, as well as specially made bat boxes.
Pregnant females seek out warm, enclosed structures which they share with others of their species. Many maternity colonies are small with only a few bats roosting together but colonies of a hundred or more are common and a few special sites, such as the Peachland Visitors Centre, support more than 2000 bats.
The diversity of bat species in our province indicates the high biodiversity and health of natural habitats. Half of the province’s bats are considered potentially endangered or threatened species at risk due to loss of habitat, destruction of roosting sites, and environmental contaminants affected bat populations and insects. Luckily many orchard and vineyard owners realize the benefit of having bats around and have erected bat houses on their properties.
As an ecologically and economically valuable group of species, bats are protected by the BC Wildlife Act. Bats can only be evicted in the appropriate season in a safe and sensitive manner. Bat eviction is not necessary if bats use outside walls as a day roost or their roost inside a building does not causing any problems with noise or guano.
If bats are entering living or working quarters or dropping guano into areas causing food safety concerns, entry point areas can be sealed off. The repairs should be done after the bats have left between November and March. A one way exit flap can be used to evict bats in March and April before the young are born and in September once they can fly. The flap or exit tunnel “bat cone” avoids trapping bats inside a building, allowing bats to exit but not re-enter.
The Community Bat Programs of BC have a website and toll-free phone line at www.bcbats.ca for information on bats, and advice on bat evictions and installing bat houses. Most regions of the province also have a community bat coordinator who can be consulted and in some cases, visit property owners who would like recommendations on bat management.
If you have a bat colony on your property or would like to put up a bat box on suitable habitat, the BC Community Bat Program would like to hear from you. Call toll-free 1-855-922-2287.
Recently the Little Brown Myotis, a species that commonly uses buildings, was listed as Endangered due to the devastating impacts of White Nose Syndrome in eastern Canada. This introduced fungus has killed approximately six million bats in North America. Since the disease is not thought to be in western Canada, community bat projects are doing all they can to promote bat conservation prior to its arrival. The “Got Bats” program is funded by the Habitat Conservation Trust Foundation and federal Habitat Stewardship Program, working with the BC Conservation Foundation.
Margaret Holm works for the Okanagan Similkameen Conservation Alliance. Contact her at outreach@osca.org.