Biologists lacking needed lynx data

SUMMIT COUNTY — Federal wildlife biologists are conducting “damage control” to help preserve the endangered Canada lynx in Colorado, in part because they don’t know enough about its primary prey.

“There’s a critical piece of the puzzle missing,” said Kurt Broderdorp, a Grand Junction-based U.S. Fish and Wildlife Service biologist charged with coordinating federal efforts to protect the threatened species.

Because biologists don’t fully understand the population fluctuations in snowshoe hares, they struggle to make decisions about logging, snowmobiling, ski-area operations and other activities that potentially can affect lynx.

“We’ve been doing damage control for the last 10 years, and now we’re at a critical point,” Broderdorp said.“ ... It’s imperative that we understand the tie between snowshoe hares and (forest) management actions.”

Vern Phinney, a White River National Forest biologist based in Dillon, said the snowshoe hare was removed from the indicator-species list — meaning forest-management practices would be monitored to confirm they are supporting lynx — because of cost.

“It would cost $200,000 per year just to monitor that species.

It would take 180 person-days per summer, or a crew of four to five people just counting rabbit poop,” he said.

The snowshoe hare doesn’t work as a management indicator species because it’s hard to differentiate whether changes in snowshoe hare populations are caused by those management actions or by the natural fluctuations in hare populations, Phinney said.

U.S. Forest Service efforts to track snowshoe hares have been scattered at best, and a recent move that dropped lynx from an important management indicator species list won’t help, he said.

Lynx, powder-loving wildcats that are common in Alaska and parts of Canada, virtually disappeared from Colorado, with the last confirmed sighting of a native cat reported in the 1970s.

Spurred by lawsuits, the federal government listed lynx as a threatened species under the Endangered Species Act in 2000.

At the same time, the Colorado Division of Wildlife launched an ambitious reintroduction program, transplanting more than 200 cats from Alaska and Canada to the San Juan mountains.

The lynx quickly recolonized large parts of Colorado, even wandering as far as Wyoming and Utah.

For several years, researchers documented successful breeding, counting more than 100 lynx kitten births.

But two years ago, reproduction dropped to zero, leading to speculation that the cats aren’t finding enough snowshoe hares, their primary food source.

State biologists acknowledged that they don’t know for certain whether hare populations in Colorado fluctuate in the same distinctive predator-prey cycle that has been well-documented in Canada and Alaska.

That same question is vexing federal biologists as they try to complete a series of forest-planning measures designed to conserve lynx habitat.

While the reintroduction program is state-run, it’s the responsibility of federal agencies to manage the land that serves as habitat for lynx.

The vast majority of lynx habitat is on U.S. Forest Service and Bureau of Land Management territory.

“They can’t manage if they don’t know what’s going on out there,” Broderdorp said.

Snowshoe-hare studies have been few and far between, and researchers have used different types of studies, making it very difficult to compile an accurate and useful landscape-level picture of hare populations.

Researchers have to use studies that can be replicated over time and in different locations to gain some measure of reliability, Broderdorp said.

“There’s no way to package the studies from 1975 to the present to give us a fairly decent time series ... You don’t have any consistency,” he said.

“The hard part is the money.

The reality is, we’re working in an environment where budgets are shrinking. The reality is, we’re doing damage control.”