North American porcupine

The North American porcupine (Erethizon dorsatum) is a big, slow rodent covered in sharp quills, about 30,000 of them on its back and tail. It is the second-largest rodent in North America, after the beaver. It is rated Least Concern and lives in forests from Nova Scotia to Alberta and from Virginia to the Yukon.

A porcupine cannot shoot or throw its quills. The quills simply come loose very easily and stick into anything that touches them. When threatened, the porcupine turns its back to the danger. It is mostly active at night and often climbs trees to eat bark, leaves and buds.

A traveller from South America

Scientists think the ancestors of New World porcupines crossed the Atlantic from Africa to South America about 30 million years ago. After the Isthmus of Panama rose about 3 million years ago, they spread north in what is called the Great American Interchange. The North American porcupine was the only one of these relatives to survive north of Mexico. The oldest clear fossils are about 130,000 years old and were found in Arkansas.

What its name means

The English word porcupine comes from old French words meaning 'thorn pig', although it is a rodent and not a pig. Its scientific name, Erethizon dorsatum, can be translated as 'the animal with the irritating back'. Seven subspecies are recognised, spread across different parts of North America. It is also called the Canadian porcupine or quill pig. The animal is also sometimes called the common porcupine.

On the globe

The model shows a porcupine in the forests of northern Ontario. Look for the spiky quills on its back and tail.