Cool critters: A license to quill

As chipmunks snooze in elaborate burrows, honeybees huddle in hives and garter snakes cluster in underground dens, a large rodent known for its spiked armor stands out on cold winter days.

And if you take a look, you’ll find that the North American porcupine, found from Washington to Maine to Alaska, is much more than a ball of quills.

This time of year, these slow-moving pincushions are fairly easy to spot among tree branches in parts of the Inland Northwest, said Shannon Doyle Verity of Tekoa, 42 miles southeast of Spokane.

“I see porcupines quite often,” said Verity, who hikes on trails near Tekoa with her camera. Typically perched high in trees, the animals simply gaze down at her as she snaps their pictures, she said. “They don’t do much but sit there and look cute.”

Cute isn’t the first word that typically comes to mind when we think of porcupines, nor is the term winter wildlife. But not only do these under-studied creatures have a cute side, they are also hardy wintertime survivalists.

Which seems odd, considering they’re covered with quills instead of thick fur and they don’t hibernate or build sturdy shelters like their beaver cousins do.

What’s more, the porcupine’s primary food source in winter “doesn’t have much more nutritional value than cardboard,” said wildlife biologist Jessy Coltrane of Montana Fish Wildlife and Parks, who studied the animals for her doctoral work at the University of Alaska Fairbanks.

“The temperature would be minus-zero and I’d look up to see a porcupine in a tree eating bits of bark, which made me wonder – ‘How the heck do they make it through winter?’ ” she recalled in an interview.

As scientists around the country peered into the lives of salmon, bears and owls, curiosity and a lack of published data drove Coltrane to research the less popular North American porcupine in Fairbanks and Anchorage.

“There’s not much scientific interest in porcupines. Compared to other mammals in the United States, not much is known about them,” she explained.

Coltrane’s research, published in two studies, reveals a few tricks they have up their quills to get through winter:

• They load up on fat during summer and fall, enabling them to burn stored body fat until spring.
• They conserve energy by moving less in winter, often spending several days or even weeks in the same few trees. They also limit their home range on ground.
• Despite a low-calorie diet of inner tree bark and evergreen needles, they don’t lose lean body mass.

When porcupines forage in trees, they inadvertently drop bits of needles, twigs and buds, turning the ground below into little feeding stations for wildlife that can’t climb trees, including deer and snowshoe hares.

“Porcupines spend much of winter in trees, unprotected from the cold, wind and snow. On top of that, they live on a low-nutrient diet,” Coltrane observed. “They’re tough little guys.”

They’re also misunderstood. Contrary to what many people believe, porcupines don’t fling their quills.

“I hear that one a lot. It’s a myth that won’t die,” said Coltrane.

Although armed with some 30,000 quills, porcupines move slowly and will typically try to waddle away from perceived attackers. If cornered, however, they erect their quills, which detach only when an object such as a dog’s nose or human’s hand comes in direct contact with them.

“Porcupines don’t run up and attack,” Coltrane explained, adding that they are shy, unaggressive animals that deploy a prickly defense system since they’re unable to run away.

In other words, they have a license to quill.