By Sharon Wootton
Special to the Herald
Ruth Milner is on the hunt, armed with traps and peanut butter.
The state Fish and Wildlife biologist is trapping voles in the San Juan Archipelago, looking for the Shaw Island vole (Micrutus townsendii pugeti).
This vole was designated a separate subspecies of the Townsends’s vole and named for the island on which it was first identified, in about 1940.
“In those days that was based on physical characteristics, the morphology of the critter,” such as the distance between eye sockets and the length of the tail, Milner said. “These were big deal mammologists. They concluded that the Shaw Island vole was a separate subspecies distinct from the mainland species.”
This subspecies has been found only on about 15 islands in the San Juan Archipelago.
“It was named after Shaw Island because that is where the first of this subspecies was found,” Milner said. If you see a vole on Orcas Island, it’s probably a Shaw Island vole.
Because it has a restricted range, the vole is vulnerable to human- and climate-created changes. It currently is on a lengthy list of species of greatest conservation needs kept by the state Department of Fish and Wildlife.
In May, Milner set traps on Shaw Island, but raccoons broke every trap. Must have been the peanut butter.
Now that the weather is cooling off, she’ll return to the islands for more vole-hunting.
“The population is in sort of a down turn right now and they’re not the easiest thing to trap. They really sense something new in their environment and tend to avoid it,” the biologist said.
Milner will take muscle tissue samples from her captured voles and from specimens from the 1930s and 1940s at University of Washington’s Burke Museum to a geneticist. DNA will determine whether the Shaw Island voles and the mainland variety are different. They can also be compared to specimens from Whidbey and Camano islands.
“If they are not different, we don’t need to have them on the list of species of greatest conservation needs” she said.
Trapping is not the only way for Milner to get her voles. Cats bring voles to their owners, lawn mowers kill voles, cars do them in.
People with dead voles can send Milner their trophies. Put the vole in a sealable sadwich bag and label it with the date, location (address or nearest landmark), and your name and telephone number. Deliver it to the Mill Creek office of the DFW. Milner has another option if you live far away: “I’ll come get them.”
For information, contact Milner at 360-631-1733 or ruth.milner@dfw@wa.go.
Vole world: Voles prefer the dense ground cover of fields and meadows, where you’ll find their interlinking narrow trails in the vegetation. They can swim, which makes a wetland area an option for living space. If you see one, think of the many dozens of its extended family lurking in the grasses and in underground burrows.
In the islands, native flower meadows bloom with Indian carrot, blue camas, chocolate lily and other flowers. Energy is stored in their tubers, corms or bulbs, many of which are cached in the burrows for winter food.
A vole excavating for food is creating a miniature version of tilling the land. When pulling out a bulb or corm, some of the bulblets or cormlets are knocked off into the loose soil and get fast starts on growing, sometimes outgrowing the grasses.
Voles stay close to home, probably not more than a quarter-acre. They do not hibernate and are prolific breeders, producing five to 10 litters a year with three to six young a litter.
Hawks, eagles and owls take advantage of sheer numbers as part of their diet, snatching voles on the runways.
Columnist Sharon Wootton can be reached at 360-468-3964.
Talk to us
> Give us your news tips.
> Send us a letter to the editor.
> More Herald contact information.
