Fisher Cats: Tough Guys of the Weasel World

Let's start with the name. Perhaps the most mislabeled mammal out there, the fisher cat (Pekania pennanti) (or, as more accurate animal pros call it, the fisher) has no relation to fish or cats, nor does it hunt either one (supposedly ... we'll get to that in a second).

"The problem with the name is, it's not a cat," says Roland Kays, research professor at North Carolina State University's Department of Forestry and Environmental Resources, and lab head at the North Carolina Museum of Natural Sciences. "It's like a big weasel, but it is cat-sized. It's closer to a wolverine."

The slim-bodied, short-legged, stout little creatures are about 32 to 40 inches (81 to 102 centimeters) long, with rounded ears and bushy tails that are about 12 to 16 inches (30 to 41 centimeters) in length. They've got glossy, dark brown coats and some pretty impressive retractable claws. They're found in various parts of the United States, from New England to Tennessee, around the Great Lake states and northern Rockies, and a smaller population lives on the West Coast in Oregon, California and the southern Sierra Nevada region.

"They're predators that live only in North America," Kays says. "They're pretty good in trees as well as on the ground in terms of running around and hunting a wide variety of things — they're famous for being one of the few animals that can kill and eat porcupines."

Yes, you read that correctly. Kays says the fisher has a lot of fun stalking, killing and consuming the prickly critter most animals would avoid like the plague. While there's no evidence to prove how the fisher does the dirty work, Kays says the grisly act is right in line with the carnivore's impressive skills. "They're the right combination of small and fast, so they circle the porcupine and then dash it, grab it by the head because that's the only part not covered in quills, and crush the skull," he says. "Most animals leave them alone but porcupines are pretty big and slow and pretty lethargic, so the fisher circles until it can bite its head. No one's ever filmed it, but we've seen evidence in the snow of what probably happened."

While the fisher probably has some fun stalking and consuming porcupine, it's less likely that it applies the same stone-cold killer qualities to other potential prey, despite what news reports say. "There's no actual physical evidence of a fisher eating a house cat and as a scientist, I like to evaluate evidence," Kays says. "They're certainly the right size, so they should be able to take down a smaller, or inexperienced, or lazy, fat house cat. But we've done a lot of tracking — and now it's interesting because they're moving into a lot of urban and suburban areas — and we've gone out and followed their footprints in the snow and we've seen them crossing with cat footprints in the same area, but have never found a dead cat and have never found cat in the fisher's diet. People attribute it to them, but it's more likely a coyote, a known cat killer, or a great horned owl. But if someone does find some evidence, I'm not going to argue with it."

Kays even wrote about the lack of evidence pinning fishers as cat murderers in his "Scientist at Work" series for The New York Times. He described how he and SUNY Albany undergrad student Paul Gallery collected 24 diet samples from suburban fishers, and while they found a lot, they didn't find cat. "Comparing our results with published studies showed that the suburban fishers ate more gray squirrels than most (20 percent of their diet)," he wrote. "There is one study on fisher diet from Massachusetts that recorded two observations of a fisher eating a cat, but found no cat hair or bones in 226 physical diet samples."

All that said, the fisher is omnivorous, so it does like to eat a variety of things, ranging from rabbits and reptiles to raccoons, mice and most definitely squirrels, which may at least partially explain why so many fishers are found in suburbia. "Everywhere I've lived on the East Coast, the suburban areas are stuffed full of squirrels, and fishers are very good squirrel hunters," Kays says. "So they find all this food and the squirrels are stupid — they'll see the fisher come running and think it's just a dog or something."

Scientists still aren't totally sure what species the fisher kills and why, and vice versa. "It's interesting because there's still stuff that's unknown," Kays says. "On the East Coast, they're doing really well and the population is growing, even with the limits of fur trapping, they're expanding into Maryland, Virginia, West Virginia, and Pennsylvania. And in the Midwest, they're doing okay. But on the West Coast, they're doing much worse. One possibility is that fishers in the West are being killed by predators like wolves and pumas, which we don't have in the East. But a strange nugget of info is that in the West, bobcats sometimes kill fishers. A lynx is bigger than a bobcat, but there are five solid records of fishers killing lynx in Maine. So, on one coast, weasels are killing cats, and on the other coast, cats are killing weasels. Maybe the eastern fishers are more badass or eastern cats are just pussycats?"

Ultimately, experts say fishers aren't actually out to get us or our pets. In fact, humans are the biggest threats to the fisher population, thanks to overharvesting for pelts, and logging and road building leading to loss of forest habitat. We're also responsible for the climate change potentially increasing the frequency of fires throughout the fisher's habitat.

"Fisher furs were worth a lot of money in the 1800s and early 1900s," Kays says. "If a hunter saw a fisher, he'd drop everything he was doing and chase it. They were given protection in the 1930s — they were really bad off, but slowly recovered and there were a variety of conservation efforts that led to the population getting better. Then they legalized trapping, but it's not that common in certain areas — certainly not in suburban areas." Another reason the fisher likes to call suburbia home.

So what do you do if you suspect you're staring down a fisher in the streets?

"Just get excited, it's awesome," Kays says. "There's nothing to fear — they don't attack people, and they're probably not going to come after pets. They're always on the move, so you'll usually just get a quick glimpse, and in urban areas, they're pretty nocturnal. So you might see a black thing running quickly at night, but you probably won't know if it's a fisher or house cat."