In 2008, Western Fishers in California were in severe jeopardy......their plummeting numbers and fragmented forest habitat a true concern to biologists.........In recent years, due to forest regeneration and reintroductions, fishers have made an impressive comeback in many parts of the East. But on the West Coast, fisher range remains "very fragmented," says Reginald H. Barrett, fisher biologist and Goertz professor of wildlife management at the University of California at Berkeley.....Unfortunately, dispersing across even relatively short distances to colonize new areas can be an insurmountable problem for fishers if it requires moving through habitat they are not adapted to. This poses serious challenges to people who are working to return fishers to their former ranges or to facilitate the expansion of established populations where habitat fragmentation is a factor.....With warming temps and more frequent fires, "If fire comes in in a big way and destroys the forest, it's not good for fishers," says Jim Strittholt, the director of Oregon based CONSERVATION BIOLOGY INSTITUTE: "If you thin the forest too much to treat for fire, that's not good for fishers either".........."There may be a way to reduce fuel load and keep the fisher," says Barrett, of the University of California. "The problem is who is going to pay for it. The Forest Service position is that they need to cut the big trees to pay for it, but the public has to decide if they want fishers and if they are willing to pay to fix the mistakes previous forest managers have made."

Fishers Fight the Odds

Scientists study individual animals in hopes of restoring fisher populations. Photo © Jim Yuskavitch By Jim Yuskavitch One night last November, while prowling a Northern California forest, the little female fisher took the bait. The raw chicken leg suspended by a piece of fishing line was simply too tempting to pass up, and the box trap within which it hung resembled the hollow logs she routinely explored on her nightly patrols. She stepped inside. As the sleek animal with luxurious chocolate-brown fur tugged at the bait, the trap door fell shut. Once her initial shock receded, she devoured the bait and curled up in the back of the trap, waiting to see what the morning light would bring.   What the rainy Humboldt County morning brought was Rebecca Green, a wildlife biologist with the Wildlife Conservation Society, who identified her catch as fisher number fifty-three by scanning a microchip that had been embedded when she was first captured a year previously. Her radio collar had fallen off in August, so Green and her fellow researchers were unable to track the fisher's movements for months, not knowing where she was or if she was even alive. They knew she had given birth to kits in the spring, but the snag she had chosen for her den was too decayed for the researchers to climb safely, so how many young she had remains a mystery—as do so many facts about these supple and secretive forest creatures, whose fragmented habitat and declining numbers are growing concerns for wildlife biologists. Fisher number fifty-three is part of a study the Wildlife Conservation Society is conducting in cooperation with the Hoopa Valley Indian Tribe to learn more about fishers, such as their den and resting site requirements, and how juveniles disperse to find their own territories. That knowledge will help the Hoopa incorporate the creature's habitat needs into the tribe's new forest management plan. The fisher is culturally important because of the tribe's historic use of its fur and because it is a fellow denizen of tribal lands. Researchers are investigating other aspects of current fisher populations, such as a recent decline in the ratio of females to males. While wildlife biologists aren't ready to sound the alarm just yet, this drop in female numbers is worth watching because it is occurring in Northern California, which is the West Coast fisher's stronghold. "Even with the decline, we still have a pretty high density of fishers compared to other areas," says Sean Matthews, who heads up the Wildlife Conservation Society's Hoopa fisher research project in conjunction with tribal wildlife biologist Mark Higley. "We're putting together a study to look at if disease is a potential cause of the decline, although it might not be just one thing." REDUCED HABITAT, POPULATION DECLINE Fishers, whose scientific name is Martes pennanti, are members of the weasel family. They grow up to four feet long—with a tail that can account for a third of that length—weigh anywhere from three to thirteen pounds and eat a variety of prey including porcupines, snowshoe hares, squirrels, shrews, mice and birds, as well as carrion and even some fruits and vegetation. Adapted to mature, closed-canopy, mid-elevation forest below 4,000 feet, fishers rely on large trees and snags for many of their needs, making them some of North America's most habitat-specialized mammals. Expert climbers, they will forage in trees and can rotate their hind feet nearly 180 degrees to descend efficiently. Hunting on the forest floor, they move quickly and fluidly, investigating every nook and cranny with the curiosity, energy and ferocity that are hallmarks of the weasel clan. Historically, fishers ranged across central Canada from British Columbia and the Yukon east to Labrador. In the United States, they roamed the Upper Midwest, Northeast and Appalachia, down the Rocky Mountains into Idaho and Montana and along the West Coast in Washington, Oregon and California to the southern Sierra Nevada. Never very common or prolific, and drawn to places that are easily exploited by humans, fisher populations collapsed when confronted with for-profit natural resources extraction. The double whammy of fur trapping in the early 1900s and the subsequent logging of old-growth forests reduced their numbers significantly. In the 1920s, a prime Pacific Northwest fisher pelt could bring up to $120, making them the second most valuable fur-bearing animals after sea otters. By the 1930s, fisher trapping was banned in the Pacific Northwest, but fisher numbers continued to decline as their habitat was extensively logged. Other factors also contributed: Fishers probably died during poisoning campaigns mounted against wolves and other predators. It's also likely they suffered increased predation by hawks and owls as logging opened up the forest canopy, making them easier to see and catch. By 1960, the only fishers left in Oregon were in the Klamath-Siskiyou Mountains—essentially a spillover of the Northern California population. The last confirmed fisher sightings in Washington were on the Olympic Peninsula in 1969. By the 1970s, they were expunged from much of their range on the West Coast and reduced to small, isolated populations. In California, only two populations—separated by 250 miles—remained. Current population estimates for West Coast fishers are extremely difficult to come by for these small, secretive carnivores. No reliable estimates of the Northern California fisher population are available, and the best guess for the southern Sierra population is 100 to 500 animals. The southern Oregon Cascades population almost certainly has fewer than fifty animals, and no fishers are known to be living in Washington. In recent years, due to forest regeneration and reintroductions, fishers have made an impressive comeback in many parts of the East. But on the West Coast, fisher range remains "very fragmented," says Reginald H. Barrett, fisher biologist and Goertz professor of wildlife management at the University of California at Berkeley. "You've got a small population in the southern Sierras, a small population in northern California and a little restored population in southern Oregon. Then you have to go all the way to British Columbia to find more fishers." The historical range of West Coast fishers is called a peninsula population because of its long, narrow shape extending from British Columbia down to the southern Sierra Nevada. The animals that established the populations on the West Coast of the United States are thought to have originated in British Columbia. The continuous flow of genetic material moving across cohesive habitat kept West Coast fishers healthy and happy until human activity began to take its toll. Unfortunately, dispersing across even relatively short distances to colonize new areas can be an insurmountable problem for fishers if it requires moving through habitat they are not adapted to. This poses serious challenges to people who are working to return fishers to their former ranges or to facilitate the expansion of established populations where habitat fragmentation is a factor. Both natural and human-made barriers have stymied attempts at reintroducing fishers. Researchers on the Hoopa Valley Reservation tracked a young male that took off westward toward Redwood National Park, where it would have found plenty of suitable habitat, but it returned to the reservation after encountering extensive clear-cuts. In the southern Sierras, the Kings River proved to be an unexpected barrier to fisher movement. For the southern Oregon Cascades fishers, agricultural lands and major highways appear to prevent them from making the short jaunt to the Klamath-Siskiyou area. Concern over the fisher's dwindling numbers led environmental organizations to petition the U.S. Fish and Wildlife Service to list the animal under the Endangered Species Act several times between 1990 and 2004. In April 2004, Fish and Wildlife found that a listing of fishers was "warranted, but precluded by higher-priority listing actions." In other words, they are at enough risk to qualify for listing under the Act, but are a lower priority than other candidate animals and will have to wait their turn. BALANCING THREATS The official decision making fishers eligible for eventual protection prompted the Forest Service, the Hoopa Valley Tribe and other groups to begin taking a closer look at how forest management practices are affecting fishers. "Given that decision and the cultural importance of the fisher to the Hoopa tribe, they want to see the fisher protected on the reservation," says Matthews. The project looks at vegetation plots to see what habitat fishers need, he says. "For example, after a tribal timber harvest, what could be left behind to keep it viable fisher habitat? How much structure does the fisher need? That's the million-dollar question." Forest managers and wildlife biologists are asking those same questions about public lands, particularly in the southern Sierras where fisher recovery has become entwined with timber issues and strategies to treat forests to prevent catastrophic wildfires. The Forest Service is currently monitoring southern Sierra fishers. "One of the big issues is how to protect fisher habitat from unduly severe fire," says Bill Zielinski, fisher biologist and research ecologist with the Forest Service Redwood Sciences Laboratory in Arcata, California. "The debate centers around if we can go into the forests that are inhabited by fishers and have good fisher habitat and take out the small-diameter fuels in such a way as to prevent crown fires but leave it as a place fishers still want to live." The Conservation Assessment and Strategy team, made up of a number of federal agencies—including the Forest Service; the states of Washington, Oregon and California; the Hoopa Valley Tribe; and the British Columbia Ministry of Environment—began in late 2005. "We're looking at the life history and biology of fishers and what the threats to fishers are so that we have the information to develop a conservation strategy," says Bob Naney, a forest wildlife biologist for the Okanogan-Wenatchee National Forest in Washington who is also co-chair of the assessment and strategy biology team.   Another project, the Southern Sierra Nevada Fisher Assessment, is being conducted by the Corvallis, Oregon-based Conservation Biology Institute under contract with Forest Service Region 5. It is using computer modeling to look at the impacts of fire on fisher habitat and how forests might be treated to reduce wildfire without affecting fishers and their habitat. "If fire comes in in a big way and destroys the forest, it's not good for fishers," says Jim Strittholt, the institute's director. "If you thin the forest too much to treat for fire, that's not good for fishers either." And that balance is a serious sticking point within the fisher's current southern Sierra range that reaches from Yosemite National Park south to the Greenhorn Mountains in southern Tulare County. "Foresters say that to prevent canopy fires you need a fairly wide canopy, and fishers are associated with high-density forests," says Zielinski. "The idea is to find a happy medium." Whether that happy medium can be reached is met with skepticism by some, especially in light of a new strategy for managing the Sierra Nevada forestlands. Timber harvest levels have significantly increased, and the forest relies on income from logging large trees to pay for removing small trees and ground fuels. That strategy, critics argue, risks compromising existing fisher habitat. "I have considerable doubt that habitat protection is what they are doing it [the logging] for, especially in areas where they are leaving very little of the canopy and forest structure the fishers need," observes Jeff Lewis, a wildlife biologist with the Washington Department of Fish and Wildlife who is working on a planned fisher reintroduction to that state. But the danger to fishers from fire is real in the southern Sierra, where a stand-replacing blaze could put the small fisher population at serious risk. The issue is whether the public is willing to pay to do what is necessary to reduce the risk of wildfire on forestlands—or to raise the money by logging in fisher habitat. "There may be a way to reduce fuel load and keep the fisher," says Barrett, of the University of California. "The problem is who is going to pay for it. The Forest Service position is that they need to cut the big trees to pay for it, but the public has to decide if they want fishers and if they are willing to pay to fix the mistakes previous forest managers have made." Both Strittholt and Naney stress that the plans their respective groups are developing will be recommendations, not mandatory prescriptions, to the Forest Service and other agencies. Meanwhile, plans are moving ahead to reintroduce fishers to Washington's Olympic Peninsula, which offers excellent habitat and enough room for the new population to expand. If all goes smoothly, the area may have a fisher population as soon as this fall, and certainly by next year. Despite the odds fishers are up against—small populations, fragmented habitat and risk from wildlife—things are looking better for them than they have in a long time. "I started as the fisher specialist in 1992," says Zielinski, "and back then it was all about spotted owls, then marbled murrelets. It's taken a while for people to learn about the animal because nobody knew what a fisher was. Since the decision that the fisher is warranted for ESA listing there has been a major shift in public attitude, and forest managers are taking fisher habitat into consideration now."