Durango investigates alternative to insecticide
City creates bat habitats in Durango

Patt Dorsey, area manager for the Colorado Division of Wildlife, displays the remains of several bats which reside at the Durango office. The insect eating capability of bats have prompted Durango to encourage the growth of bat populations to help stem the tide of the West Nile Virus./Photo by Todd Newcomer.

by Adam Howell

Durango is doing its best to attract some unusual full-time residents. The City of Durango is working to foster bat habitats with the hope that it will help with mosquito abatement next summer and reduce the threat of West Nile Virus. Residents are being encouraged to do the same.

Durango recently bought and installed several bat houses made by the Division of Wildlife, according to Kathy Metz, Parks and Recreation director. Made of western red cedar, the houses are designed to be mounted on the sides of buildings, away from foot traffic.

Presently, Colorado has 18 or 19 different species of bats, depending on whom you ask. But in the southwest, Dorsey said some of the more frequent species likely to inhabit the houses are the little brown myotis, the free-tailed bat, the big brown bat, and the Western long-eared myotis.

Although bats are often seen at sunset during the summer taking an apparent indirect course to nowhere, individual bats have been documented eating about 600 mosquito-sized insects per hour, which can help make a dent in the mosquito population, Patt Dorsey, Colorado Division of Wildlife's area manager, said. Their hunting ability can be attributed to their echolocation - a sensory system in which high-pitched sounds are emitted and their echoes interpreted to determine the direction and distance of objects - which they use to track mosquitoes.

"Bats have been gaining popularity," Dorsey said, adding that their reputation has sometimes been that of creatures of the night or flying mice that get tangled in people's hair. "All of those kinds of myths have been debunked over the years. And so people are starting to appreciate them."

Yet our cultural fear of bats is similar to that associated with the fear of insecticides used to kill mosquitoes.

"If your insect problem is absolutely horrible, maybe it's appropriate to spray," Dorsey said. "But if it's not that bad, maybe some of these other things, like the mosquito dunks, the fish are a great one - just think about the number of larvae they eat, and bats."

By mosquito dunks, Dorsey is referring to bacillus thuringiensis, bacteria that pose a minimal threat and can be put into standing bodies of water to kill mosquito larvae.

Patt Dorsey displays one of the bat houses available for sale at the Colorado Division of Wildlife. /Photo by Todd Newcomer.

By mosquito dunks, Dorsey is referring to bacillus thuringiensis, bacteria that pose a minimal threat and can be put into standing bodies of water to kill mosquito larvae.

The city got the bat house idea from Clay Patton, a member of the Parks and Forestry Board, who many years ago went to Kathmandu, Nepal, on a business trip, where he saw thousands of bats.

"I noticed there were these really weird looking trees that were all black," Patton said of his experience. A local worker told him that they weren't really black trees at all, but trees where the bats live. "Upon closer inspection, I noticed there were fruit bats, which are really large bats, hanging from every tree limb."

The suggestion - which came around the time West Nile Virus was starting to rear its head in La Plata County - was based on the premise that the bats would eat mosquitoes much in the same way fruit bats eat mosquitoes to mitigate malaria in Nepal, he said.

While bats are not at risk of overpopulating our region in an invasive manner, they do sometimes get rabies and die almost immediately from it, Dorsey said.

When it comes to a successful bat house, patience is mandatory, according to Dorsey. Bats are picky about where they live, and it can take up to several months for them to move in. Specifically, bats like homes with moderate temperatures, free from paints or stains, she said. Likewise, bats that are not roosting in the houses tend to roost in pi`F1ons, junipers, sagebrush, grasslands, barns and abandoned mines and cabins.

Unlike a birdhouse, a bat house has a slat on the bottom, where the mammals enter, Dorsey said.

Bat houses are available for sale to the public in two different sizes, for $18 and 20, respectively, at the DOW Visitors Center, near the 16th Street fish hatchery.