Researchers — and detection dogs — scour the southern Oregon coast to track the elusive, endangered marten

 

By JULIET GRABLE/Jefferson Public Radio 

On a warm day in late June, Jessica Buskirk, Alyssa Roddy, and Mark Stevens bushwack through a coastal forest just east of Gold Beach. The three wildlife biologists carefully navigate over downed logs and duck under branches, winding through a tangle of rhododendrons.

This dense, sloping forest is bound by a forest road on one side, near the confluence of two creeks.

“It’s one of my favorite spots, in the heart of the home range of F11,” says Buskirk,

F11 is a coastal marten, also known as the Humboldt marten — a small, fluffy member of the weasel family. Buskirk is project and crew lead for one of several coastal marten projects being coordinated by Dr. Katie Moriarty, senior research scientist at the National Council for Air and Stream Improvement, a research organization that works on behalf of the forest products industry.

Finally, the small group reaches their destination: a large golden chinquapin tree that towers over neighboring trees and shrubs. The trunk is partially split along its length; about 20 feet up, a long vertical cleft opens into a crack just large enough for a marten to squeeze through.

Mosquitos buzz. After making sure F11 isn’t there, Stevens checks the game camera that’s strapped to a tree nearby, while Buskirk and Roddy inspect the chinquapin. There’s a large cedar log at its base, making for a handy platform.

“This is like a marten playground,” says Roddy.

“There’s so much good structure here,” agrees Buskirk.

The cedar log platform is covered with marten scat, or poop. Buskirk’s crew will collect it and survey the vegetation around the tree before moving on to another of the 120 sites in the study area. It’s painstaking work that will take a good part of the summer.

Martens have high metabolisms, and they have to eat continuously. When they’re not eating, they seek refuge in places where they can be safe from predators.

“We want to know, is there a specific composition within the forest that martens are keying into in order to select these rest sites?” explains Buskirk. Understanding this could help managers better protect and restore habitat for coastal martens.

For the biologists, it can feel like a race against time. Only several hundred coastal martens exist, and their range is small, spanning from Cape Perpetua in Oregon to Trinidad on California’s north coast. Researchers are worried that a single catastrophe could send the species on the path to extinction. They are striving to learn as much as they can about the threatened creatures and the challenges they face, which include climate change and wildfires.

Bundle of contradictions

During a break, Roddy shares a picture on her phone. In it, F11 is scurrying up the chinquapin tree, a small rodent in her mouth.

The biologists puzzle over what it could be: a mouse? A Douglas squirrel? Maybe a flying squirrel?

F11 is fitted with a GPS collar so researchers can track her — one of about 30 martens the researchers have trapped over the last three years, but the image was snapped by a game camera. As much time as biologists spend in the woods, actual sightings are somewhat rare.

Like all coastal martens, F11 has pointy ears and inquisitive round eyes; she looks a little like a cat; a little like a fox. Adorably fuzzy but ferocious; shy but curious; vulnerable but venerable hunters — the contradictions are part of what has hooked researchers like Buskirk and Moriarty on the elusive weasels.

“Martens have explosive personalities beyond any other creature,” says Moriarty. “They have to eat about a quarter of their body weight every day. That makes them a little bit desperate and a little bit ‘hangry.’”

They eat a varied diet: berries, birds, voles, insects — “you name it,” says Moriarty, who has been studying martens for nearly 25 years. Fierce enough to attack animals larger than themselves, martens are also targeted by a host of predators, including bobcats, cougars, coyotes, owls, and raptors.

The coastal marten is a subspecies of the Pacific marten, which is found west of the Rocky Mountains. Trapping and destruction of its coastal forest habitat shrunk its numbers, and it was thought to be extinct until the late 1990s. Now, Moriarty suspects that there are fewer than 700 individuals, confined to several small and isolated populations in southwest Oregon and northwest California.

Until recently, it was also assumed that coastal martens, like their cousins, dwell primarily in old growth forests, where abundant mossy limbs and rotting logs provide safe places to rest. In 2014, Moriarty spent the summer surveying for martens on the central Oregon coast. It wasn’t until the end of the summer that she found a single animal — not in the forest, but in thick vegetation in the dunes nearby.

“It was so surprising that we expanded the surveys using remote cameras,” says Moriarty. The cameras, which snap a picture anytime they detect heat or motion, captured more martens in the Oregon dunes.

In 2015 and 2016, Moriarty’s team radio collared several martens to learn more about these strange dune dwellers. They discovered two genetically distinct populations: one north of the Umpqua River and the coastal town of Reedsport; one south of the river. Both populations — fewer than 100 individuals in all — inhabit the dense native dune vegetation, where there are plenty of berries and rodents to eat and plenty of places to hide.

Threats and unknowns

In 2020, coastal martens were listed as threatened under the federal Endangered Species Act. Like other “mustelids,” or weasels, martens are susceptible to several diseases, including COVID-19. Because there are so few individuals, a single disease outbreak could devastate a population.

Wildfire is another growing concern. Over the past several years, wildfires in northern California and southwest Oregon have burned through marten habitat. Ironically, treating forests to make them more resilient against catastrophic wildfires — thinning and prescribed, or intentional burning — could further fragment the forests they use.

The Oregon Dunes National Recreation Area, which is part of the coastal marten’s critical habitat designated by the U.S. Fish and Wildlife Service earlier this year, is wildly popular with off-highway vehicles, or OHVs. An annual gathering called the UTV Takeover draws tens of thousands of OHV enthusiasts to the Oregon dunes each summer, where they ride, race, and show off their dune buggies, quads, and dirt bikes. This year, for the first time, two Takeover events are scheduled.

In June, the Center for Biological Diversity sued the U.S. Forest Service for failing to protect coastal martens from the off-highway vehicles.

The dune population is “fragile,” says Tala DiBenedetto, staff attorney at the center. “Since the marten was listed, we really haven’t seen anything from the Forest Service in terms of doing a proper analysis and putting measures on the ground to protect martens from all this off-road vehicle activity.”

These measures could include fencing to keep OHVs within designated riding areas, signage, and enforcement of noise levels. Many people are unaware of martens, says DiBenedetto. “It’s the Forest Service’s responsibility to educate visitors and riders to the presence of martens in the dunes.”

Jody Phillips, president of Save the Riders Dunes, calls the lawsuit “flawed.”

“To lock us out is to effectively kill more and more of the open sand,” says Phillips, adding that after the Forest Service planted European beachgrass and other vegetation to stabilize the dunes, the portion of open sand has rapidly declined. According to Phillips, OHV riders are only allowed access to about 19 percent of the dunes; of that, most is open sand. A small portion is trails through vegetated areas where the marten could be.

Moriarty with NCASI says there isn’t definitive data on whether OHVs are harming martens. It’s even possible that in some cases the vehicles help martens by scaring off predators like bobcats that are sensitive to noise.

The issue is “far more complex than people make it out to be,” says Moriarty. “It’s not being studied, but it could be.”

Bringing in experts

Because the martens themselves are so elusive, marten researchers rely on cameras, tracking devices, and scat to learn more about their behavior and habits.

“With each scat, we get its weight worth in gold of information,” says Moriarty. Not only can they discover what the martens are eating, they can identify the individual that produced it. They can even analyze hormones and learn if the animal was under stress.

Marten poop is about the size and thickness of a pinkie finger and “twisty,” like rope. It’s easy enough to spot at a known site like the chinquapin tree, but finding it in other parts of a marten’s territory is a little like looking for a needle in a haystack. For this reason, Moriarty’s projects rely on other experts.

While Buskirk’s crew sets up transects to survey vegetation near F11’s rest site, Jennifer Hartman, co-founder of Rogue Detection Teams, threads through the brush with Filson, her “detection dog” partner. A 10-year-old cattle dog mix with a salt-and-pepper coat and matching brown eyebrow spots, Filson has used his sensitive nose to detect the scat of a host of creatures, from cougars and wolves to caterpillars and bee nests.

Filson lightly jumps onto the cedar log, where he easily discovers the trove of marten scat. He “freezes” for a split second, looking back at Hartman.

“Good job!” she says, and immediately offers Filson a large red ball. Filson takes it eagerly, and Hartman gently turns it around while Filson mouths it.

Working with a detection dog is a true partnership, says Hartman. Successful teams utilize the human’s knowledge of the species and its habitat, the power of the canine’s nose, and the bond between owner and dog.

“I’m not just using the scat itself; I’m taking in the entire gestalt of the area,” explains Hartman. “The tree, the cavity, big downed tree — that just screams mustelid.”

When she and Filson search for marten scat, she doesn’t just randomly walk around and hope the dog catches the scent.

“What we’re looking for is teeny, teeny tiny,” says Hartman. “We have to get the dogs to those features — the downed mossy log in the middle of this tangled habitat.”

She and Heath Smith, the other co-founder of Rogue Detection Teams, are spending 10 days surveying known marten haunts up and down the coast. They are focusing on priority sites where martens have been detected before, either with cameras or by dogs who found their scat.

The scat they collect on these surveys will be sent to Taal Levi’s lab at Oregon State University. This summer, they plan to start using scat to show how the martens are related to each other genetically — something that’s never been done before.

Questions upon questions

Marten surveys are costly and logistically difficult. Hartman, who has worked with detection dogs all over the world, says looking for scat in the thick coastal forests and shrubby dune environment in Oregon “takes the cake.” “It’s really thick, really intense. It tends to be really steep,” she says.

The U.S. Fish and Wildlife Service has designated 1.2 million acres in northwest California and southwest Oregon as “critical habitat” for the coastal marten. But Moriarty worries that conservation decisions are being made based on information that isn’t completely accurate — the assumption that coastal martens only live in old-growth forests, for instance. This concern makes her work all the more urgent, as she and other researchers try to learn as much as they can about these elusive creatures.

Recent camera surveys detected fewer martens in some areas in the Oregon dunes than in previous years, but there’s not enough information to say that this population is declining.

Population trends are “uncertain and speculative,” says Moriarty, adding that answering this question would require extensive surveys using cameras, detection dogs, and trapping and collaring martens. As of now, there is no funding for estimating populations anywhere in the marten’s known range.

“I love the collaboration we have,” says Moriarty, who regularly consults with regulators, agencies, tribal and private industrial landowners. “But there’s not enough funding.”

Buskirk says that each discovery about coastal martens leads to more curiosity about them. They’ve spotted martens in newly burned landscapes and caught them running through one-year-old clearcuts, for example.

“All of the places that they are in push the boundaries of what we know,” says Buskirk. “There are so many questions.”

• This story appeared Aug. 24, 2024 on Jefferson Public Radio.