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Poking around the lives of prickly porcupines among us

Nocturnal and mostly solitary, porcupines are the second-largest rodents in Massachusetts after the beaver, according to MassWildlife.Bill Byrne/MassWildlife

On a sunny spring day some 15 years ago, I was helping my friend and fellow biologist, Tim Beaulieu, with vernal pool surveys in the Dracut woods. Suddenly, what appeared to be a light sprinkle of rain began falling about 10 feet from us.

“That’s weird, I don’t see any clouds,” I said. “Where is that rain coming from?” Upon closer observation, we realized it wasn’t rain at all, but rather a porcupine urinating from a tree branch about 30 feet above. I don’t see porcupines often, so it was exciting, in spite of almost being peed on.

Most people aren’t concerned about being urinated on by a porcupine; they’re concerned about getting stuck by its quills. Porcupine quills are hollow, modified hairs with sharp tiny barbs at the tip, according to Mass Audubon’s porcupine web page. The black and white quills cover the porcupine’s body except for the face, belly, inner thighs, and underside of the tail.

Contrary to folklore, porcupines cannot shoot their quills — they turn their backs toward a potential predator when threatened and raise their quills. They also vocalize and swat their tails if a predator persists in trying to attack. The quills release and lodge in the attacker’s body if it makes contact with a porcupine.


Quills are difficult to remove, and can travel deeper into the tissue, so it’s important to get medical help for both humans and pets that have been impaled, said Dave Wattles, black bear and furbearer biologist for MassWildlife.

The author, Don Lyman, holding two porcupine quills. Don Lyman

The North American porcupine is found in forested areas from Alaska to the Northeast. In Massachusetts, they are most common in the western and central part of the state, but are also found in parts of Eastern Massachusetts, such as Middlesex County, according to MassWildlife.

Porcupines are the second-largest rodents in Massachusetts after the beaver, according to MassWildlife, and can measure 25 to 31 inches in length. Their weight ranges from about 12 pounds in spring to 20 pounds in the fall, with males being larger than females.


Most predators avoid porcupines, except one — the fisher. These large members of the weasel family can grow up to 3 feet long, and kill porcupines by circling them and biting the porcupine’s face if the opportunity presents, said Roger Powell, professor emeritus at North Carolina State University. If the fisher is able to wound and weaken the porcupine with bites to the face, it flips the porcupine onto its back and bites into the porcupine’s unprotected belly.

When confronted by a fisher, a porcupine does its best to protect its face, Powell said.

“A porcupine that can tuck its face between the roots at the base of a tree, or between rocks, is a safe porcupine,” said Powell.

Other predators kill porcupines occasionally, but bobcats and coyotes, which tend to bite prey on the back of the neck, can die if they get their faces covered with quills, Powell said.

“Pumas also kill porcupines, but not nearly as frequently as do fishers,” said Powell. “Pumas appear to slap porcupines’ faces with their paws, making their attacks similar to fishers’ attacks.”

Porcupines are active year-round, but aren’t seen that often because they are nocturnal and mostly solitary.

They breed in the fall, and as you might imagine, porcupine mating is a delicate business. The female curves her tail over her back so that her quills don’t impale the male, and lays the rest of her quills flat against her body, which allows the male to mount her briefly with little danger, according to livescience.com.


A single baby, called a “porcupette,” is born about seven months after mating, said MassWildlife. The porcupette’s quills are soft, but harden within a few days. The mother cares for the baby until it is about 5 months old, when it goes off on its own.

Various studies documented porcupines living from 18 to 21 years, said Wattles.

Porcupines are herbivores and eat plants, berries, and nuts during summer and fall, said MassWildlife. In winter, porcupines feed mainly on conifer needles and tree bark. Hemlock trees are one of their favorite foods, said Wattles.

Salt is lacking in porcupines’ diets, so they are drawn to edges of roads where salt has been spread in winter, which can lead to them being hit by motor vehicles, said Wattles. They also gnaw on bones for salt.

Porcupines don’t hibernate, but when temperatures are very cold, or when there is deep snow or heavy rain, they use den sites in rocky outcrops, rock piles, and hollow trees, said MassWildlife. Sometimes they share dens in groups called “prickles.”

A strong scent of ammonia may be an indication of a porcupine den nearby, said Wattles.

“Porcupine scat piles up where porcupines den,” said Wattles, “so if you catch the scent of ammonia, look around for signs of a porcupine den.”


Send your questions about nature and wildlife in the suburbs to donlymannature@gmail.com.