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Endangered ferret hangs on
By BUZZY HASSRICK
This document was published online on Thursday, December 11, 2003
Last summer's tally of 52 black-footed ferrets in Shirley Basin, one new home of the endangered animal, proved a milestone.
"The record number is arguably the most significant breakthrough in ferret recovery," Martin Grenier of Lander says.
The non-game mammal biologist with the state Game and Fish Department recently presented a program about ferrets to the Meadowlark Audubon Society.
Of the 11 sites where the ferrets have been introduced, the animal is thriving best in South Dakota and well in Wyoming. About 228 were released in Shirley Basin between 1991-94, Grenier said.
The ferret joined the endangered species list in 1967 and was thought extinct nine years later, he said. Then in 1981 a dog from a Meeteetse ranch killed one that was robbing its food bowl.
The rancher took the animal to a taxidermist, and G&F was notified about the find.
At the Meeteetse site, wildlife officials counted 61 ferrets, 23 adults and 38 kits, he said. They surveyed the area, identified habitat and started formulating a program, which included potential recovery sites.
"The only ferret native to North America is dependent on prairie dogs for prey and their burrows" for homes, Grenier said.
As officials developed a captive breeding program, they continued to monitor the Meeteetse site, counting 129 ferrets in 1984.
"In 1986 the population crashed, dropping below 20," Grenier said.
The cause was an outbreak of canine distemper. Because G&F officials determined the remaining 18 ferrets were at high risk of "extirpation" and because no new populations had been found, they decided to trap and remove the survivors, he said.
The breeding program at the Sybille Research Unit was established "with the goal of releasing them in the wild," Grenier said. In 1995 the U.S. Fish and Wildlife Service took over Sybille, which continues today, and expanded the programs to one international and four national zoos.
"The emphasis was on national recovery," Grenier added.
Annually, 200 or more ferrets are released into the wild in the West and Mexico. Meeteetse was not included because of the disease outbreak.
Instead, officials selected Shirley Basin between Casper and Laramie, which comprises 142,000 acres inhabited by prairie dogs.
Tallying ferrets is difficult, Grenier said, as the populations move among prairie dog villages.
"It's a secretive and nocturnal animal," he added.
But officials did find that, after the four years of introductions, ferret numbers started declining in Shirley Basin.
"The most we ever found was 24," Grenier said.
Then came the count during six nights in August 2003 by 12 staffers, who spotted 52 animals on 5 percent of the range.
"That was the most ferrets ever found and the smallest survey ever assembled," Grenier said.
For the future, he said, the recovery program must secure funding and continue collecting data on the population's genetics. It also must explore a possible second release site in Wyoming.
"We need to gather more information before we can say the Shirley Basin population is established," Grenier added. "But it is definitely good ferret habitat."
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