North American Porcupine
Scientific Name: Erethizon dorsatum
The North American Porcupine (hereafter referred to as “porcupine”) is the second largest rodent in North America. It is distinguished by its stout body and a spiny coat. They range from dark brown to black, with a bit of yellow and white in their quills. A porcupine can have up to 30,000 quills. These quills have microscopic barbs on the tip. When lodged in tissue, it becomes very difficult to get them out, as the barbs pull the quill in deeper with any movement.
Porcupines are skilled climbers and have special adaptations to do so. They have long claws and palms with a unique pebbly texture to help them grip the trunks of trees. Their tail and quills also aid in preventing them from sliding down the tree when climbing. Porcupines are sexually dimorphic, with the males being larger than the females.
Adult size: 23 to 35 in
Weight: 11 to 31 lbs
Life span: Average life span is 6 years, but they can live up to 18 years old.
Maturity: ~2 years
Litter size: 1 to 2
Fun Fact
A baby porcupine is called a porcupette! Porcupette’s are born with soft quills that harden within a few hours of being born!
Diet
Porcupines are herbivores, eating a wide variety of plants. What they eat, and how much they eat changes seasonally. They are generalists and eat whatever is available to them at the time. In the growing seasons, they reduce their feeding rate when there is higher quality food available. In the fall, they increase their feeding rate, preparing for the winter where there is a scarcity of materials to forage.
Porcupines will eat the buds, bark, and cambium of deciduous trees, along with needles from evergreens. They also consume nuts and seeds that have fallen to the ground, though these foods are highly sought after by a variety of other mammals and can be difficult to compete for.
Habitat
Porcupines use a wide variety of habitats, at varied climates and varied elevations. These include tundra, deciduous forest, mixed forest, and chaparral etc. Based on their location, they may spend more or less time in trees vs on the ground. In New York, porcupines are mainly tree-dwelling. This is most likely related to the amount of ground cover available to shelter them from predators.
In Eastern habitats, they prefer to spend their time in hemlock trees. In the winter, they will find ground and rock dens to escape from the cold.
Behavior
Porcupines spend most of their time alone, though they will gather in dens during the winter months. Both males and females are defensive of their territories, and do not usually do not venture far outside their established home ranges, however, they have an interesting mechanism for dispersal.
In porcupines, the females are the ones to disperse. Dominant males will keep the same territory for up to 3 breeding seasons, which means the females run the risk of mating with their fathers. The male porcupine does not contribute to raising the young, so there is no way for the porcupines to distinguish their relation. To avoid this, the females disperse instead.
Reproduction and Life Cycle
Porcupines are polygynous, meaning the male mates with multiple females in the breeding season. Males will defend a female from other males a few days prior to the female entering estrous. Females maintain a territory and will defend it from other females, while male territories often overlap with multiple female territories.
Male territory size is determined by their age and social status, with older more experienced males having larger territories farther from their natal area. Males engage in a mating ritual in which they douse the female in his urine. They will do this until the female shows that she is receptive to mating. The breeding season is short, occurring in October and November.
Population Status
Porcupines are listed as of “least concern” on the IUCN Red List.
Viewing
Porcupines can be seen throughout much of upstate New York. The largest populations are in the Adirondacks and the Catskills. Try looking up! They spend a lot of their time in trees, particularly hemlocks.
Range
The North American Porcupine has the northern most range of all porcupine species. They inhabit much of North American, as well as Canada and Alaska. They are widespread throughout New York State, but have higher densities in large continuous tracts of forests like the Adirondacks, Catskills, and Tug Hill Plateau.
