UW/WDFW predator-prey study assesses changes in behavior
Lauren Satterfield hikes up a snowmobile path. The snow around her is all story today, lined with tracks like words on a page. First there are the marks of scavenging birds — wingtip brushes from a raptor taking off, the plunge print of a raven landing, triangles of magpie feet.
Then there is blood, splatters here, eagle footprints lined pink with it there, and a pool at the edge of a large depression where two bodies fell. Bound marks lead to this place from beneath a ponderosa, and a trench of drag marks lead to the next spot, ending at a mule deer. Or what’s left of it.
It’s mostly rib cage now, the rumen — full of sour-smelling grass — and a set of still-perfect legs. Satterfield points out the fur carpeting the ground around this and another kill nearby, oblivious as tufts stick to her boots. “All this hair,” she says, “they’ll shear it off before they eat. It almost looks like somebody took shearing scissors to the hide.”
It’s the kind of inverted morning where frost haloes the vegetation along the river bottoms, but hills like this one, north of Highway 20, are warm with sun, and Satterfield is looking for cougars.
Compact, with a blonde bun, Satterfield is one of five graduate students working on a long-term predator-prey study overseen by the University of Washington and the Washington Department of Fish and Wildlife (WDFW). The cougar that made this kill wears a GPS collar. Satterfield, lead field tech Nate Rice, and a trio of local hound handlers — Steve Reynaud, Bryan Smith, and Bryan’s son Hunter — are hoping to locate the cougar with telemetry equipment to confirm that a second set of tracks they found this morning belongs to a new cat. They want to collar her as well.
Though the team is tracking cougars, wolves are the impetus of the Washington Predator-Prey Project. After 80 years of absence, at least 122 wolves, divided among 22 packs, wander the state. Scientists and managers want to know whether and how their return will rejigger the web of interactions between the larger predators, smaller predators like bobcats and coyotes that might scavenge kills, and the deer and elk that people also eat.
Satterfield’s portion of the project focuses on wolf-cougar interactions. “We’re trying to just understand what it means to have both of these top predators back on the landscape,” she explained.
Since the project began in 2016, field crews have collared 50 cougars in their Okanagan County study site and their northeastern study site, in Pend Oreille and Stevens counties, 32 of which are still in the study. The crews also visit areas they call “clusters” where concentrations of GPS points transmitted by the collars show that cougars have lingered, a sign that they’re feeding, to record data about the cougars’ prey, and where they choose to eat it.
In the Methow Valley, 12 previous years of cougar data ending in 2013 could provide helpful pre-wolf reference for changes to things like cougars’ home range sizes and what parts of the habitat they’re using, says WDFW cougar and bear specialist Rich Beausoleil, Satterfield’s state supervisor.
Will the cats shift their hunting up in elevation and deeper into forested areas as wolves move in, Satterfield wonders. And will proximity to development like homes and farms make a difference?
“Part of what makes this unique is that we’re studying these interactions in a human-dominated landscape,” she said. That means the results, when the project is complete in a couple of years, will be more relevant for understanding the mixed-ownership habitats that most animals navigate than those conducted in protected areas like national parks. And this coming year, with a grant from the National Geographic Society, Satterfield will purchase some new collars with accelerometers that measure sudden bursts of speed indicating a hunt. She wants to know whether developed areas confer hunting advantages, perhaps by compelling deer to congregate. That, in turn, might make trouble for cougars, if more come into conflict with people’s livestock and pets, and are killed by officials or landowners.
Catching a cougar
Now, though, there is the not-so-simple matter of catching another cougar, in an area that the houndsmen have struggled with on past studies. “It’s the Bermuda Triangle,” Bryan Smith joked, his blue eyes crinkling. “I’ll tell you one thing: You’ll sure see the dogs run. I don’t know what it is out there. The cats learn to fly or something.”
The second cougar track, at the valley bottom a 20-minute snow machine ride from the two kills, passes an empty dog box the houndsmen left overnight, then crosses a log spanning a washed-out road. Where domestic dogs loop aimlessly through the snow, cougars are usually headed to somewhere, from somewhere, Satterfield said. And this one, the hounds reveal as they begin to race and bellow along its trail, transcribed a diagonal line across the snow towards the hilltop.
The field crew paces the hounds by snow machine on the road below, then hooks right up another road, for a better view.
The hope is that the hounds will tree the cat. If they do, Satterfield will use a CO2 dart rifle to shoot it with immobilizing drugs. She’s also got a climbing harness and spurs, should she need to ascend. Besides fitting the collar and noting weight and other data, the crew will use a special hole-punch to take a DNA sample from its ear as they affix a numbered eartag.
Each autumn, before the winter tracking season starts, Satterfield practices the whole scenario by putting stuffed animals high in a tree and darting them through the branches. Her current favorite is a character from “Where the Wild Things Are” that’s “stuffed super densely,” better approximating the resistance of a living animal’s skin.
She won’t get the chance to use those skills today, though. There’s too much bare ground and the dogs have lost the scent. The crew spends the next two hours collecting them, then two more roping and retrieving a snowmobile that bogged on a steep slope.
A lot of the work is like that — tedium, troubleshooting, miles and miles of hard travel on foot and on snowmobile. With the clusters it’s the same: To reach the ones on private land, there’s sifting through records, making phone calls, and doorknocking for permission. “It’s definitely not all National Geographic action-packed adventure,” Satterfield said. “There’s a lot of repetition, and you need a lot of patience.”
Finally, all the dogs are settled into their boxes. It’s been an 11-hour day, but when Satterfield revs her sled onto the trailer, she doesn’t look exhausted. She’s beaming.
Sarah Gilman is a Methow Valley-based freelance journalist who formerly was an editor at High Country News.