Zoo-aided study reveals secret life of forest carnivores

August 2, 2013 - 2:35pm

Cameras document rare fox, record raccoon in first part of two-year study

Last winter, biologists Tim Hiller and Jamie McFadden-Hiller planted 32 roadkill-baited motion-sensitive cameras in the snowy wilds of Oregon's Central Cascades.

After six months and more than 25,860 photos, they have begun to paint a picture of Oregon's forest carnivore diversity — capturing images of eight meat-eaters ranging from weasels to black bears, along with a few surprises.

Among them was one of North America's most familiar mammals.

"We camera-trapped a raccoon at 5,950 feet in the Three Sisters Wilderness in January," said Dr. Hiller, a biologist with the Oregon Department of Fish and Wildlife. "We're not sure why it was up there or how it was surviving in the deep snow and harsh winter conditions. As far as I know, this is the highest-elevation raccoon ever documented, at least for a native population during winter."

According to Hiller — who plans to publish the raccoon finding and photograph in a scientific journal later this year — the extremely unusual sighting may be more than just an anomaly.

"With climate change, raccoons have been moving not only farther north but also probably higher in elevation, although this was much higher than we would have expected," Hiller said. "It's unlikely that there would be more of them up there, but if there are, it could result in some changes in the wildlife communities over the long term."

The cameras also captured images of the little-known and almost-never-seen montane red fox, a high-elevation specialist that might also be affected by increasingly warmer winters. As temperatures rise, the rare fox comes into more frequent contact with its competitor and predator, the coyote.

The survey's most-photographed carnivore was the American marten, a forest-dwelling member of the weasel family whose presence is an indicator of forest health and diversity.

"We assumed we'd get many images of marten," Hiller said. "But it was both unexpected and encouraging to see them at so many sites, including in burned sites like at the Santiam Pass. Of course, these marten may have just been passing through these areas, and that would be a good question to address with future efforts."

See more camera trap images and a report of the survey on this PDF.

"Understanding which carnivore species are using the Central Cascades is profoundly important to making decisions about how we manage the land," said Dr. David Shepherdson, deputy conservation manager with the Oregon Zoo. "When we provide healthy habitat for carnivores, many other species benefit."

This coming winter, Hiller and McFadden-Hiller will redeploy their cameras, this time adjusting some of the bait stations to target montane red fox as well as continuing efforts to detect Oregon's most elusive forest carnivore, the wolverine. While reported sightings aren't uncommon, there has never been any photographic evidence of the legendary predator in Oregon's Cascades.

"Camera setups are not foolproof and we could miss a wolverine, but this tool has become invaluable for studies like these," Hiller said. "Some people are convinced that wolverines are present in the Oregon Cascades and others highly doubt it. Perhaps we'll find out this coming winter."

Made possible by the Oregon Zoo Foundation's Future for Wildlife program, this project is a partnership of the Oregon Department of Fish and Wildlife, U.S. Forest Service, U.S. Fish and Wildlife Service, Oregon Wildlife, the Oregon Zoo, The Wolverine Foundation and others.