North American Porcupine

North American Porcupine Fact File

Erethizon dorsatum

Credit: Potawatomi Zoo, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Weight

3.5-7kg

(7.75-15.5lbs)

Length

64-80cm

(25-31.5in)

Lifespan

Wild 18 years

Captive 18 years

Diet

Herbivore

Wood, Bark, Seeds

Conservation Status

IUCN

Least Concern

The North American porcupine is the second largest rodent found in their range of North America.

Despite many myths these animals are unable to shoot any of the 30,000 quills which cover their back at predators. The quills are hardened keratin, the same substance as hair and are loosely attached to the skin. When a predator disturbs them they break off.

These animals are herbivores and feed on the bark, wood and seeds in their environment. Their specific food sources vary seasonally.

Unfortunately their taste for wood has brought them in to conflict with humans as they may damage ornamental trees.

Read on to learn more about these magnificent mammals.

Appearance

What does the North American porcupine look like?

North American porcupines are most notable for the barbed quills which cover their back, rump and tail. These are thickened hairs. As a new world porcupine species their quills are set individually in the skin. Each individual quill can measure up to 8cm (3in) long.

To help them grip trees as they climb the soles of the feet are naked of fur. They have sharp claws to help hold on. These claws are long and as such they walk with a pigeon-toed gait. These are an adaptation to dig for roots.

Across the back the quills are yellow-white with a black or brown tip to each. The remainder of their body is covered by brown fur. Each porcupine have as many as 30,000 quills covering their body.

The teeth of the North American porcupine grow constantly during their life as an adaptation to the hard items on which they feed.

At the end of the body is a short tail which will measure between 15 and 30cm (6-12in) long.

They reach a length of between 64 and 80cm (25-31.5in) long with an average weight of between 3.5 and 7kg (7.75-15.5lbs). Males tend to be larger than females.

Diet

What does the North American porcupine eat?

North American porcupines are herbivores. Their diet includes a range of wood, bark, needles, buds, roots, seeds and leaves.

These animals have been recorded to chew on antlers and bone to obtain salts due to them being commonly sodium deficient.

They have a wide variation in their diet across the seasons.

Credit: Fiver, der Hellseher, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Range

Where can you find the North American porcupine?

The North American porcupine is found across much of North America as their name suggests. Here they live in parts of Canada, the United States and Mexico. In the United States they primarily live in west of the country. Their range extends north in to Alaska.

Habitat

What kind of environment does the North American porcupine live in?

North American porcupines make their home in dense forest, tundra, grasslands or desert shrub.

Dens are made in caves, hollow trees of brush piles.

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Reproduction

How does the North American porcupine produce its young?

In winter they will seek out a female. Prior to mating he will urinate on her. Soon after mating the female will chase him away. Males have multiple mates each season but only where the female is willing.

Males become territorial during the breeding season and are highly vocal. They often fight over mates.

Females give birth to a single infant after a 205 to 217 day gestation period. On a rare occasion twins may occur. At birth the quills are soft but they harden over the first hour of life.

Pups first try solid food a week after birth. They will leave their mother by six months old.

Sexual maturity is reached by 2.5 years old.

Behavior

What does the North American porcupine do with its day?

North American porcupines are active by night when they will seek out food on the ground.

During the day these animals will seek out shelter in a hollow tree, cave or the disused burrow of another animal. Here they will sleep. Throughout the year they will change the location of their den.

While they do not undergo a hibernation they will remain in their den through times of harsh weather. During cold weather they may share their den with another porcupine.

These animals are adept climbers and will seek out food in the trees. They are also good swimmers. As their quills are hollow they can float in the water.

North American porcupines are not territorial and allow other porcupines to pass through their habitat. They do not tolerate others at trees with a good food supply though.

During courtship they are highly vocal. They will make use of whines, screeches, grunts, a high-pitched squeal and hoots.

Credit: Peupleloup, FAL, via Wikimedia Commons

Predators and Threats

What is impacting the survival of the North American porcupine?

Natural predators of the North American porcupine include wolverine, mountain lion, bobcats, lynx, fishers and American minks.

Many predators have learnt to attack the porcupine and flip it on to its stomach so that they can attack the unprotected underside.

Their main method of defense is the quills which are present across their back. If these are stuck in to an attacker they will detach from the body and drive further in to their body.

When faced with a threat they will chatter and release a foul odor. They can also contract the muscles at the base of their quills to make them stand up.

These animals are considered to have a stable and widespread population across most of their range.

The largest threat they face is hunting and in Mexico they are near extinction as a result of this. Much of this hunting is retribution for attacks on property, trees and car tires.

They are also subject to vehicle strikes and loss of habitat.

Quick facts

Their Latin name translates to “quill pig.”

North American porcupines are the second largest rodent in North America after the beaver.

A group of porcupines is known as a prickle.

Credit: Norbert Potensky, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons

References

Burnie, D., 2011. Animal. 3rd ed. London: DK

Jackson, T. and Chinery, M., 2012. The illustrated encyclopedia of animals of the world. London: Southwater.

Emmons, L. 2016. Erethizon dorsatum. The IUCN Red List of Threatened Species 2016: e.T8004A22213161. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T8004A22213161.en. Downloaded on 19 October 2021.

North American Porcupine — Erethizon dorsatum. Montana Field Guide. Montana Natural Heritage Program and Montana Fish, Wildlife and Parks. Retrieved on October 18, 2021, from http://FieldGuide.mt.gov/speciesDetail.aspx?elcode=AMAFJ01010

Smithsonian's National Zoo. 2021. North American porcupine. [online] Available at: <https://nationalzoo.si.edu/animals/north-american-porcupine> [Accessed 19 October 2021].

Nhpbs.org. 2021. North American Porcupine - Erethizon dorsatum - NatureWorks. [online] Available at: <https://nhpbs.org/natureworks/porcupine.htm> [Accessed 19 October 2021].

Chesapeakebay.net. 2021. North American Porcupine | Chesapeake Bay Program. [online] Available at: <https://www.chesapeakebay.net/discover/field-guide/entry/north_american_porcupine> [Accessed 19 October 2021].

San Diego Zoo Kids. 2021. North American porcupine. [online] Available at: <https://kids.sandiegozoowildlifealliance.org/animals/north-american-porcupine> [Accessed 20 October 2021].

Adfg.alaska.gov. 2021. North American Porcupine Species Profile, Alaska Department of Fish and Game. [online] Available at: <http://www.adfg.alaska.gov/index.cfm?adfg=northamericanporcupine.printerfriendly> [Accessed 20 October 2021].

Zoo Idaho. 2021. Zoo Idaho - North American Porcupine Fact Sheet. [online] Available at: <https://zooidaho.org/animals/fact-sheets/north-american-porcupine/> [Accessed 20 October 2021].

Zoonewengland.org. 2021. North American Porcupine | Stone Zoo. [online] Available at: <https://www.zoonewengland.org/stone-zoo/our-animals/mammals/north-american-porcupine/> [Accessed 20 October 2021].