North American Porcupine

• It eats bark, leaves, shoots and herbaceous plants.
• It lives in forest, open tundra and desert scrub across much of North America.
• Its quills are in fact modified hairs with microscopic barbed tips.
• defensaIts quills carry tiny microscopic barbs at the tip, much like a fish hook, which makes them hard to pull out once lodged in an attacker's skin.

Skeleton type

Vertebrate - internal bony skeleton (mammal)

Habitat and environment

Forest, open tundra and desert scrub across much of North America

Birth weight

~450 g at birth (about a pound), precocial, eyes open and with soft quills that harden within an hour

Size at birth

~450 g at birth

Sexual maturity

15-16 months (a first litter in its second autumn)

Gestation / incubation

205-217 days (~7 months)

Litter / clutch size

1 young per birth (twins rare)

Life expectancy in captivity

Documented record of up to 23.4 years

Sources consulted: Animal Diversity Web · PA Game Commission · NHPBS NatureWorks · Zoo New England · AnAge (genomics.senescence.info) · Smithsonian National Zoo

Best time: All year round, at night; it is easiest to find in winter, when its outline stands out against the bare branches as it gnaws at the bark.