DNA helps rebuild fisher family tree
Diane Tipton Montana Fish | Hagadone News Network | UPDATED 13 years, 8 months AGO
A few million years ago a very slender,
secretive, cat-like creature successfully claimed territory in
North America and lived in balance with other species.
Then, in a wink of time, the American
fisher became the most sought after furbearer of all time. In the
1800s, a trapper new to the Rocky Mountains could make a month’s
wages with the sale of one fisher pelt. During this time, Montana’s
native fishers were believed to have become extinct.
Fishers are of the mustelidae or weasel
family. They are dark brown to black, pointy faced, beady eyed and
sleek with a luxurious long, fluffy tail. However, few of us will
ever see one due to their solitary natures.
Fishers are specialists at hunting
porcupine, and also feed on snowshoe hare, other small mammals, and
on occasion insects, nuts, berries, mushrooms and even carrion.
A search for records of fishers trapped
or observed between 1930 and 1959 turned up nothing, said Ray
Vinkey, Montana Fish, Wildlife and Parks biologist in Philipsburg.
Officials concluded fishers were extirpated, that is they no longer
existed in Montana.”
That may sound like the end for
fishers, but in fact it was a new beginning.
Between 1959 and 1963, 78 fishers from
British Columbia and another 110 from Minnesota and Wisconsin were
released in various locations in Montana and Idaho to reestablish
the species, Vinkey said. In addition, from 1989 to 1991, 110
fisher from Minnesota and Wisconsin were introduced to the Cabinet
Mountains.
Vinkey’s graduate thesis completed in
2003 explored what happened to descendants of the 110 fisher
released in the Cabinet Mountains. At that time, Michael Schwartz,
with the Rocky Mountain Research Station in Missoula, was studying
fisher in central Idaho.
Looking back, this was the beginning of
a ground swell of interest in fisher, Vinkey said.
Vinkey found some, but not many, fisher
in the Cabinet Mountains. His work included DNA analysis of fisher
tissue samples supplied by Montana trappers and collaboration on a
research paper published in 2006. Trapping of the fisher continues
today with an annual quota of seven fisher.
Ray and his colleagues began to bring
in some fisher hair and tissue samples for DNA analysis that
contained a distinctive gene nonexistent in the source populations
provided to the Montana by British Columbia and mid-west states,
said Schwartz, now head of the DNA lab he helped establish at the
RMRS.
“We found fisher in north-central Idaho
exhibited this same gene,” he said.
The startling but logical conclusion
was that the gene came from native fishers, previously unknown to
exist.
The necessary proof that was needed
rested on locating a fisher from Montana or Idaho that lived well
before any introductions of fisher from other states. After a lot
of searching, Vinkey and Schwartz found a museum specimen at the
Harvard Museum of Comparative Zoology that was collected in 1896 in
the Northern Rockies. A DNA sample revealed the distinctive native
gene.
Today most native fishers are found
along the Idaho/Montana state line from Darby to Lookout Pass west
of St. Regis on the Montana Idaho border.
“Next we want to gather more precise
information about fisher, which we can do by using hair snares and
genetic analysis,” Vinkey said.
Today, a far-ranging, collaborative
study using DNA analysis to help estimate the distribution, number
and origin of fisher in Idaho and Montana is underway.
Collaborators include Montana Fish, Wildlife and Parks; Idaho Fish
and Game, Lolo National Forest and other national forests in Idaho
and Montana; the Coeur D’Alene Tribe; the Potlatch Lumber Company
in Idaho and others.