Biologists study desert frog to save it from endangered status

BOISE, Idaho - In southwestern Idaho's arid Owyhee Mountains, the Columbia spotted frog clings to life in the tiny creeks and seeps.

Boise State University researchers are studying the amphibian in the hope more information will keep it off the endangered species list. And since the real concentrations are on private land, some cattlemen have joined up to ensure both spotted frogs and livestock survive in the Owyhees.

The Columbia is about 3 inches long and has a golden belly. It is found throughout the Great Basin. The Owyhee frogs are a subpopulation.

The make-or-break issues are whether grazing harms the frogs and if they can move when drought or development alter the habitat.

''If the frogs can't withstand these problems, it doesn't look good,'' said master's student Janice Engle, who wrote the study plan.

The Bureau of Land Management asked Boise State to study the frog when it became apparent that it could be a candidate for protection under the Endangered Species Act. Also lending their support are the U.S. Fish and Wildlife Service, Idaho Department of Fish and Game and the Idaho Herpetological Society.

Student researchers found a good number of frogs, mostly in the Mud Flat area near Grand View. Now Engle wants to know more.

''They undergo a fluctuating cycle, which can be explosive in wet years. We want to know if they're in recovery or not,'' she said.

Engle has attached tiny ''passive integrated transponders'' or PIT tags on 1,900 frogs at 11 different sites. It's the same technology researchers are using with salmon in the Columbia Basin. It will give Engle the history of the frogs as she recaptures them. Her plans call for returning to each site every year for a decade to evaluate their progress.

With the bulk of the frogs on private land, those evaluations will be crucial, Boise State biology chairman Jim Munger said. The frogs congregate in springs where the water is a constant temperature or among the roots of streamside vegetation.

''We do have some indications that very heavy grazing can expose them to predators and trampling at the end of the season when water holes get smaller,'' Munger said. ''But modest grazing may be OK by getting rid of choking vegetation. ... It's a double-edged sword.''

A key variable is the frogs' travel habits. While migratory between the seeps and nearby meadows, their travel is limited to the watershed they start in. Munger said the frogs do not venture across parched land so any disruption to their specific watersheds can severely affect their survival.

After years of uncertainty created by federal attempts to protect one species or another on their range, ranchers on the high desert are trying to work with the researchers.

''It's been a positive effort, I think,'' said Bruneau-area rancher Cindy Bachman, who is a member of the go-between Owyhee County Natural Resources Conservation Committee.

''It can be a real apprehensive thing for the ranchers,'' she said. ''There is the awareness that the frog habitat needs to be considered when water developments are considered.''

Munger is optimistic about the Owyhee frogs' short-term survival. Amphibians are a key indicator of the environment's health because they spend their lives both in a watery or streamside habitat. Except for livestock, the area is largely unchanged and the water is not polluted by chemicals.

But with development pressures beginning to expand beyond the traditional areas in central Idaho, Munger fears Owyhee County could be the scene of the next rush for recreational property.

''I think in terms of 10 years or five years, we're probably OK,'' he said. ''If you look in terms of 100 years or 500 years, is the whole place going to be turned into miniranches? I just don't know.''


Use the comment form below to begin a discussion about this content.

Sign in to comment