DENVER (AP) — Denver parks managers who recently gassed hundreds of prairie dogs near Central Park in the Stapleton neighborhood are trying a different tack to protect city green spaces.
They'll erect "raptor poles" above problem prairie-dog colonies — perches for red-tailed, Swainson's and ferruginous hawks and other sharp-taloned predators.
The idea is to encourage natural predators to rein in animals that are damaging the landscaping and evading non-lethal control methods.
The morphing of traditional square bluegrass parks into vast connected corridors in urban areas is widely welcomed by people who love open space. But the animals — prairie dogs, deer, geese, raccoons, coyotes, skunks and foxes — use it as habitat. They find water, food and protection.
"The better the natural predation, the better it is for the ecosystems at large," said Scott Gilmore, deputy manager of Denver Parks and Recreation and a wildlife biologist.
Gilmore is overseeing the installation of wooden poles north of the Stapleton neighborhood, near the Northfield mall, where expanding prairie- dog colonies are devouring wider and wider swaths of grass, he said.
Parks crews first tried luring prairie dogs with molasses-laced traps and relocating them. This is complicated because a state law requires approval by county commissioners before prairie dogs can be moved to a different county — assuming prairie dogs take the bait.
"They're not going into the traps anymore," Gilmore said.
Then, parks managers killed problem populations and donated carcasses to recovery centers for raptors and ferrets. But colonies in east Denver, along the border with Aurora, still were expanding last summer. Prairie dogs don't drink. They get the water they need by eating vegetation.
So parks crews this fall resorted to poison gas, dropping Fumitoxin pellets into burrows, killing hundreds. Residents who saw warning signs posted during the operation objected.
"I'm taking this on. It's a safety issue," Gilmore said, noting that prairie dogs can spread disease, including plague, to pets. "In parks like what we have in Denver, there's no easy way to coexist with prairie dogs when we have kids and pets in the area."
Other experiments in managing urban wildlife target coyotes.
Nearly 30 have been collared recently in a federal-government-run tracking project to develop "hazing" methods that could help keep urban coyotes wild.
Coyote conflicts with pets and people — 16 bites reported in four years around metro Denver — prompted the project. Coyotes are hassled using air horns, pop cans filled with coins and bright lights in attempts to condition bolder coyotes to use parks but avoid people.
Colorado wildlife officials increasingly receive calls from urban residents reporting sightings and conflicts with wildlife. They're unable to dispatch biologists unless an animal is sick or injured. They encourage city officials to develop local plans for how best to protect people and also help animals, said Liza Hunholz, Denver-area wildlife manager for Colorado Parks and Wildlife.
Historically, wildlife conflicts in Colorado have been handled by homeowners. State law, rooted in rural traditions, lets property owners kill coyotes, skunks, raccoons and foxes at any time of year without a hunting license if the animal is causing damage.
But options for urban residents to take action are limited.
Yet urban landscaping for better recreation favors more wildlife, Hunholz said.
"If a piece of habitat is contiguous to another one, or connected in some way, it tends to have more value for different wildlife species," she said. "It gives them more room to move, more habitat features, and the ability to find more habitat."