Porcupine

Quick Take

• Porcupine quills do more than just hurt predators. They also serve a surprising secondary purpose that protects the porcupine itself. Antibiotic quill properties →
• A sodium craving drives porcupines to gnaw on objects you'd never expect, and some of those objects are genuinely dangerous. Their salt-seeking behavior →
• The animal that keeps porcupine populations in check is not a bear or a leopard but something far less obvious. Fishers as key predators →
• Porcupine quills harden on a timeline that makes the first hours of a porcupette's life a race against vulnerability. Porcupette birth vulnerability →

The largest species of porcupine, the African crested porcupine, is the third-largest rodent on the planet, after the capybara and beaver. Porcupines are divided into two types: Old World and New World porcupines. These large rodents are known to fight off enormous predators, and they feast on plants, shrubs, and trees throughout the year. Despite their fierce-looking exterior, they are gentle and docile creatures unless provoked.

Porcupine Top Facts

• Quills have an antibiotic grease layer that helps to prevent infection from accidental self-pricks.
• Porcupines have the ability to fight off even the largest and most dangerous of predators, including leopards.
• Baby porcupines are called porcupettes, and a group of porcupines is called a prickle.

Classification and Scientific Name

The taxonomy of Porcupines is broken down into the order Rodentia and the Erethizontidae (New World) or Hystricidae (Old World) family. The Hystricidae porcupines stay on the ground for the most part and live in Europe, Asia, and Africa.

Erethizontidae porcupines enjoy climbing trees and swimming, and live throughout the Americas. The name ‘porcupine’ originates from the Old French word porcespin, which translates to ”thorn pig’.’ There are over two dozen species of porcupines across the world.

Evolution and Origins

Porcupines are large, terrestrial rodents known for their sharp quills. They belong to the family Erethizontidae and are native to North America, South America, and parts of Africa and Asia.

The earliest known porcupines date back to the Eocene epoch, around 55 million years ago. They evolved from a common ancestor shared with other rodent groups such as beavers and rats. Over time, they developed their distinctive quills as a defense mechanism against predators.

Porcupines are herbivores with a varied diet, mostly eating tree bark, fruits, and vegetables. They are also known for gnawing on bones for their minerals.

Porcupines have a slow reproduction rate and usually have only one litter per year, with most species giving birth to a single offspring, though some Old World species may have one to two young. They are also known for their longevity; some species can live up to 20 years in the wild.

Appearance and Behavior

Each species of porcupine looks a bit different from the next. However, they do have some general appearance characteristics, such as having robust bodies and small heads. Their quills are either grouped together or individually embedded in their skin and hair. These quills are their defense. They drop their quills in the path of a potential predator to protect themselves.

The front of their bodies is most vulnerable as it is covered with hair rather than quills. The base color of the hair can vary, including yellow, brown, grayish brown, dark brown, or black. The patterns that overlay the base layer can also vary in color, including black, orange, yellow, and white.

There are even albino porcupines in some parts of the world. North American porcupines range between 25 and 35 inches long, which includes their tail, while smaller Old World species measure only 15 to 19 inches. They typically weigh between 3 and 53 pounds, depending on the species. Both males and females are roughly the same size. Many species have hairless soles that make them excellent climbers.

Porcupines are solitary animals that spend most of their time alone. They will gather in groups during the winter and spend time with a potential mate during courtship. A group of porcupines is called a prickle. When they do gather as a group during the winter, you will find a group of up to 12 porcupines sheltering together.

Habitat

The New World porcupines are primarily found in the Americas, whereas the Old World porcupines are often found in Europe, Asia, and Africa. Porcupines in the Americas enjoy exploring trees and water as much as land.

However, porcupines in other parts of the world typically remain on solid land. You will find them living in nearly any type of terrain, including deserts, forests, grasslands, mountains, and rainforests.

They can adapt quite easily to their environments. Many porcupine species prefer to shelter in rocky crevices, caves, tangles of roots, brush, tree branches, burrows, and hollow logs or trees. Their home, wherever it may be, is called a den. They do not hibernate; however, they are nocturnal, sleeping during the day and foraging at night.

Diet

Porcupines the world over are herbivores. They eat roughly 0.9 pounds of food each day. During the winter, they rely upon tree bark as a primary source of nutrients. Due to harsh conditions and a low-protein winter diet, they lose approximately 30–35% of their body fat reserves, while largely conserving their lean body mass. In spring, porcupines prefer leaf blades rich in protein. If trees begin to develop toxic tannins, they will select more herbaceous plants and trees with fewer tannins.

Summertime brings about more dietary changes, including potassium-rich foliage. This can lead to excreting too much sodium, which forces porcupines to go in search of salt. In nature, they may find salt in a variety of sources, such as aquatic plants.

When they do not find it in nature, they look for human-made sources, including tires, plywood, handles of tools, and brake lines. In some instances, they will eat certain nuts and fruit. Despite their dietary habits in nature, they cause far less damage than insects, disease, winds, and fires.

Predators and Threats

The small stature of a porcupine, particularly young porcupines, makes them vulnerable to several predators, including great horned owls, black bears, bobcats, martens, long-tailed weasels, ermines, coyotes, and mink. The fisher is their most common predator. Fishers can even prevent porcupine populations from growing.

If a predator does approach, the porcupine will turn its back to the predator, keeping the quills facing the threat at all times. However, if the predator can flip the porcupine onto its back, the porcupine will often lose the battle. In some instances, porcupines have fought off an attack with their quills, including against highly dangerous animals like a leopard. When an approaching predator gets a quill embedded in its paw or body, it will often retreat as the quills are quite painful and difficult for animals to remove.

The Philippine porcupine is categorized as Vulnerable, though it may not be the only threatened species, as others such as the Palawan porcupine may share a similar classification. The biggest threats to the global porcupine population are human deforestation, wildfires, and infrastructure development. These actions displace porcupines from their homes and force the slow-moving rodents to search for new sources of food and shelter. Cars are also considered a threat to porcupines, as porcupines move too slowly to safely cross roads.

Reproduction, Babies, and Lifespan

The mating ritual of porcupines includes only dominant male porcupines mating with several females, and less dominant males may not mate at all. Males defend their mate for several days during the breeding season to fight off other potential suitors.

Females will also fight for their territory against other female porcupines. Male suitors are attracted to the scent and vocalizations of females. Mating occurs only once a female selects a male and becomes receptive to his advances.

The annual breeding season lasts from October to November. A female will carry her young for 210 days and give birth to a single offspring. Baby porcupines are typically born in April or May, and they are called porcupettes.

Newborns weigh between 0.88 and 1.17 pounds and are 10 inches long. Their hair is soft at birth. Quills will harden after a few hours. Their eyes often do not open for several days. The mother nurses the offspring for a short time. After five months, the offspring will become entirely independent and be left to survive their first winter on their own.

The average lifespan of a wild porcupine is five to seven years. Porcupines raised in captivity might live up to 10 years. The Prague Zoo is known to have had an Indian crested porcupine for at least 30 years. As porcupines age, they can suffer from disease and loss of senses that make them more vulnerable to predators and natural death.

Population

All but one porcupine species are considered of least concern at this time. As a result, population studies are not overly accessible, making it difficult to determine the global population size of porcupines. The only known threats to population growth at this time are the fisher (a predatory animal) and human development.