Winter 2008
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With an antenna mounted on a broomstick, Fort Lewis, Wash., Fish and Wildlife Biologist Todd Zuchowski walked slowly through the Debalon Oak Stand, listening for a faint beep from the radio he carried.

The closer he got to one particular Douglas fir, the louder the tone became and he knew he had found what he was looking for: the Western gray squirrel.

Jason Kaye

A Western gray squirrel peers out of a trap on Fort Lewis. Biologists estimate that there are only about 25 squirrels left on the installation.

Zuchowski completes this exercise three times a week, tracking the furry critters via their radio telemetry collars.

"One of the things we want to study...is how the Western gray squirrel is using the habitat in this area and how they are possibly competing with the Eastern gray squirrel," Zuchowski said.

"Our whole objective in this is to try to augment this population by quite possibly bringing on squirrels from the other two populations in Washington," he said.

The Western gray is a species of concern. There are only about three distinct populations of Western gray squirrels in Washington. One is on Fort Lewis. Gene Orth, fish and wildlife biologist for Washington State Department of Fish and Wildlife, estimates a population of 25 to 50 Western grays on post.

"I'm leaning toward the lower end of that, actually," Orth said. Because the populations are so isolated from one another, there is very little genetic diversity in the Fort Lewis population, Orth said.

Western gray squirrels are native to Washington, while Eastern grays, a smaller species, are exotic and were introduced to the state, Zuchowski said.

"When (the Eastern gray) comes into an area that has had Westerns, the Western population goes down," said Orth. "So there is something going on, we're just not sure how it's happening."

Another issue for the Western gray is habitat. Western grays like a mixed oak and conifer woodlands habitat, one that has dwindled since the last Ice Age, Zuchowski said.

Zuchowski, is studying things like how the squirrels use the habitat, how far they travel, their reproductive cycle and how they compete with the Eastern gray. The biologists hope to start introducing squirrels from other populations to Fort Lewis in the fall.

Biologists bait live traps with walnuts and strategically place them in areas where squirrels are active.

Orth uses a special denim cone to work with the trapped squirrels. When the squirrel enters the cone and runs down to the end, Orth twists the fabric, essentially immobilizing the squirrel. Velcro flaps allow for easy access to the animal's ears and underside. Orth takes tissue samples, tags the ear, weighs the animal, determines gender and places a radio collar on the squirrel before setting it free. Armed with this information, the biologists will work to improve the Fort Lewis habitat to make it as Western gray squirrel-friendly as possible.

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