File:BLM using satellites to study fishers in southern Oregon (26433968755).jpg

BLM using satellites to study fishers in southern Oregon

By Toshio Suzuki, April 14, 2016

Capturing a fisher in an Oregon forest can be tricky work.

First off, there aren’t many of them.

Secondly, the cat-sized mammal sports retractable claws and a heart rate that can climb to 300 beats per minute when agitated — double a high rate for humans — and like most animals in the wild, they will defend themselves from capture, even if for scientific research.

“They are carnivores and they have amazing capacities of strength and endurance,” said Katie Moriarty, a research wildlife biologist for the U.S. Forest Service.

Moriarty is one of several partners helping the Bureau of Land Management in a first-of-its-kind research project: using GPS collars and satellites to track fisher movements in Oregon.

The end goal is to establish a baseline of habitat information for a species that has been in decline since the trapping and timber industries entered the Western landscape in the 1800s.

In 2014, the West Coast fisher received a “proposed threatened” status by the U.S. Fish and Wildlife Service; but just this week the agency announced the fisher did not warrant listing under the Endangered Species Act.

If land managers like the BLM can learn specific habitat characteristics, they will then be able to make more informed decisions and even potentially figure out why the member of the weasel family is in decline, said Bruce Hollen, a wildlife biologist for the BLM in Oregon and Washington.

“Something about their habitat is affecting their ability to disperse,” said Hollen. “We don't know how come their populations have stayed so small.”

Adult fishers can weigh about 3 to 13 pounds, and can be about 2.5 to 4 feet long. They eat seemingly anything smaller than them that can be discovered in the forest: birds, squirrels, mice, reptiles, insects, vegetation and fruit. They also have the unique ability to hunt and eat porcupines.

Porcupines love to eat Oregon trees and are the reason why there were several efforts to reintroduce fishers to the southern Oregon Cascade Range from the early 1960s to early 1980s.

Those reintroduced fishers were mostly from British Columbia, but also Minnesota, according to a 2003 study published in the international journal Biological Conservation.

Presently, there are only two known fisher populations in Oregon. One is native and one is the reintroduced population. Both home ranges for the distinct fisher populations are slivers in the southwestern portion of the state. Research data now indicates that native fishers have crossed the I-5 boundary from the west and made it into the historic range of the non-native population.

While wildlife biologists agree that any mixed breeding would be interesting, it isn’t always as easy as that for territorial animals.

Moriarty, who works at the Pacific Northwest Research Station, related the moving fishers to a typical American street: “You might be able to walk into somebody’s yard but you won’t be able to live there.”

Chicken meat bait is what draws the curious fishers into the multi-compartment traps. Once inside and anesthetized, the biologists have 30 minutes to affix collars and conduct a number of tests.

Blood, hair and tissue samples are taken for DNA testing. Feet are measured and a tooth is extracted to determine age. The wildlife biologists even check for fleas and ticks during the evaluation, all while monitoring the animal’s temperature.

“You only get them in your hands every so often, so you want to measure as much as you can,” explained Matt Broyles, a BLM wildlife biologist in Klamath Falls contributing to the ongoing research.

Out of the seven fishers captured last October, three adult females got the GPS collars and two adult males were fitted with regular radio telemetry collars. Juveniles were released. The females got priority for the new equipment because they tend to stay within the home range, while males “can decide to go for a long wander,” said Hollen.

“We really want to see what they are doing within their home range — how they use the landscape in that Klamath Falls area,” he said.

The GPS units provided real-time data points every 15 minutes, allowing the team to discern resting sites and den locations inside trees.

So far, the wildlife team, which includes specialists from Oregon State University and the Rocky Mountain Laboratories, is very optimistic about the research study that runs through this July.

“The benefits are exponentially phenomenal,” said Moriarty.

tsuzuki@blm.gov