Naturespeak

Whistler’s Bat World

By Cathy Conroy and Stéphane Perron

Whistler Naturalists

Few animals invoke as many negative reactions from people as bats.

Creepy little rodents flying through the dark of night just waiting to scare the living daylights out of you? Oh, please.

Let’s dispel a few myths about bats: They don’t get caught in your hair, they won’t suck your blood (at least not B.C.’s bats), they aren't rodents with wings, and they don't all carry rabies. In North America, one in 1,000 bats captured in the wild IS infected with rabies, about the same level as found in pigs.

But let’s discuss the bats that we have living here in Whistler. The Whistler area is probably home to Hoary Bats and Silver-Haired Bats, secretive loners of the bat world. More common, and more communal in nature, two of Whistler’s most common bat species are Little Brown Bats ( Myotis lucifigus ) and Big Brown Bats ( Eptesicus fuscus ). The Little Brown Bats can be seen all the way in to the sub-alpine in the summer.

There has been practically no work done studying bats in the Whistler area. Even generally speaking, bats are not well studied. They are notoriously difficult to study in the wild, and research interest has simply lagged behind the study of other mammals.

Whistler’s bats only eat insects – tons of them (literally) in a year. One little brown bat weighs as much as an Oreo cookie (6 grams) and can eat about 600 mosquitoes during an hour of nighttime feeding. Considering that your typical little brown bat spends four-five hours feeding each night, that’s a lot of mosquitoes, certainly better than your average patio bug zapper or mosquito coil can do. In fact, a small colony (100) of little brown bats will eat about 19 kg of insects over the summer months. Now that’s insect control!

Since bats are effective at reducing mosquito populations, bats will play a role in reducing the risk of being bitten by a West Nile virus-carrying mosquito. Bats can safely eat West Nile mosquitoes without becoming infected. There is a concern that in the fight against the West Nile Virus, more pesticides will be used to kill mosquitoes. Because accumulated pesticide residues get released when bats use their fat reserves during migration or hibernation, bats are susceptible to poisoning by pesticides.

All of B.C.'s bats have quite low metabolisms. In order to save their energy for night time feeding, they seek out warm, secure spots to roost during the day – places like attics or barns, under shingles, under tree bark or in specially made bat houses. During the day bats lower their heart and breathing rates, and depending upon the weather they will sometimes slip into a day-time torpor or hibernation-like state. When dusk arrives, they leave the security of their roosts and seek out areas close to water to forage the night away.

The reproduction rate of Canadian bat species is limited to one litter per year, usually consisting of a single young. Two species, including the Hoary bat, can produce two to four young. Because of their modest birth rate, if many bats are killed within a short time, the population may not recover until many years later. This also makes bat populations susceptible to extirpation (local extinction).

Thankfully, many of the misconceptions about bats are being dispelled through research and education. The importance of their role in keeping insect numbers down is finally coming to light.

UGLY! Dr. Mark Brigham, University of Regina, speaks at MY Place, Thursday May 22, 7:30 pm. Admission by donation. Doors open at 7 p.m.

Relying heavily on pictures, Mark will touch on many of the myths that surround these common mammals (one in four species of mammal is a bat). He'll describe some of their feeding habits, places where they roost, hibernation, touch on rabies and other public health concerns, and reproduction. He'll finish his talk with a discussion of general conservation issues and why bats should be considered. Then those interested in a closer introduction to bats are encouraged to join Mark for a guided search for Whistler bats.

Meet at 7 a.m. at the bottom of Lorimer Road, by the entrance to the Catholic Church. Guided by fabulous and friendly locals like Nancy Ricker, Michael Thompson, Heather Baines, and Karl Ricker. Everyone welcome – novices especially! Bring binoculars and a field guide if you have them.

Meet at the parking lot at One Mile Lake (enter by the Welcome to Pemberton sign) at 8 a.m. Guided by five experts with the Breeding Bird Survey: Barry Janyk, Kevin Bell, Dave Aldcroft, Derrick Marven, and George Clulow. These guys are exceptional birders who make it fun for experts and novices alike. Everyone welcome (bring binoculars and a field guide if you have them).

Wednesday, May 21 will be held in conjunction with Bats! walk, Thursday, May 22 leaving from My Place following presentation.

Wednesday, May 28, 6:30, Lost Lake Parking Lot. Come check out the Lost Lake wetland. Amphibian focus. Everyone welcome.

Wednesday, June 4, 6:30, End of Lorimer by the Catholic Church. Join in celebrating Eco-week.

For more information on the Whistler Naturalist Society or any of our upcoming events, contact Veronica Sommerville at veronicarobin@yahoo.ca