Hedgehog Facts and Pictures

A hedgehog is any of the small spiny mammals of the subfamily Erinaceinae and the order Erinaceomorpha. There are 16 species of hedgehog in five genera, found through parts of Europe, Asia, Africa, and New Zealand. There are no hedgehogs native to Australia, and no living species native to North America; those in New Zealand are introduced. Hedgehogs have changed little over the last 15 million years. Like many of the first mammals they have adapted to a nocturnal, insectivorous way of life. The name 'hedgehog' came into use around the year 1450, derived from the Middle English 'heyghoge', from 'heyg', 'hegge' = hedge, because it frequents hedgerows, and 'hoge', 'hogge' = hog, from its piglike snout. Other folk names include 'urchin', 'hedgepig' and 'furze-pig'.

Hedgehogs are easily distinguished by their spines, which are hollow hairs made stiff with keratin. Their spines are not poisonous or barbed and, unlike the quills of a porcupine, cannot easily be removed from the animal. However, spines normally come out when a hedgehog sheds baby spines and replaces them with adult spines around the first year. When under extreme stress or during sickness, a hedgehog will lose spines.

Hedgehogs are most closely related to gymnures.

A defense that all species of hedgehogs possess is the ability to roll into a tight ball, causing all of the spines to point outwards. However, its effectiveness depends on the number of spines, and since some of the desert hedgehogs evolved to carry less weight, they are much more likely to try to run away and sometimes even attack the intruder, trying to ram into the intruder with its spines, leaving rolling as a last resort. This results in a different number of predators for different species: while forest hedgehogs have relatively few, primarily birds (especially owls) and ferrets, smaller species like the Long-eared Hedgehog are preyed on by foxes, wolves and mongooses.


All hedgehogs are primarily nocturnal, although different species can be more or less likely to come out in the daytime. The hedgehog sleeps for a large portion of the daytime either under cover of bush or grass or rock or in a hole in the ground. Again, different species can have slightly different habits, but in general hedgehogs dig out dens for shelter. All wild hedgehogs can hibernate, although not all do; hibernation depends on temperature, abundance of food and species.

Hedgehogs have 5 toes on their front paws with short nails. However, on their back paws they have 4 toes with long, constantly growing nails. They have these characteristics because hedgehogs burrow.

Hedgehogs are fairly vocal, and communicate not only in a series of grunts and snuffles, but sometimes in loud squeals (depending on species).

Hedgehogs occasionally perform a ritual called anointing. When the animal comes across a new scent, it will lick and bite the source and then form a scented froth in its mouth and paste it on its spines with its tongue. It is not known what the specific purpose of this ritual is, but some experts believe anointing camouflages the hedgehog with the new scent of the area and provides a possible poison or source of infection to any predator that gets poked by their spines.

Similar to opossums, mice, and moles, hedgehogs have some natural immunity against snake venom due to the protein erinacin in the animal's muscular system.

Hedgehogs perform well with other pets, including cats and dogs. They are occasionally threatened by these animals, though, but for those rare instances, the hedgehogs just roll into a ball until the threat is gone.

Although formerly classified in the insectivore family Insectivora, hedgehogs are almost omnivorous. Hedgehogs feed on insects, snails, frogs and toads, snakes, bird eggs, carrion, mushrooms, grass roots, berries, melons, and watermelons. In fact, berries constitute a major part of an Afghan Hedgehog's diet in early spring after hibernation. The hedgehog is occasionally spotted after a rainstorm foraging for earthworms. Although forest hedgehogs, most well-known to Europeans, are indeed mainly insectivores, this is not necessarily true for other species.

In areas that have hedgehogs in the wild, they are often welcomed as a natural form of garden pest control. Many people leave food out to attract hedgehogs. Although hedgehogs are lactose-intolerant, they will eagerly consume cheese, milk, and dairy products, causing illness. The common pet hedgehog (Four-toed Hedgehog) can however have a small portion of cottage cheese as a dietary supplement. Dog and cat food are better than dairy, but both are often too high in fat and too low in protein. It is best to leave out only a small treat, leaving them plenty of appetite for the pests in one's garden.

Depending on the species, the gestation period is 40-58 days. The average litter is 3-4 newborns for larger species and 5-6 for smaller ones. As with many animals, it is not unusual for an adult male hedgehog to kill newborn males.

The hedgehog's dilemma is based upon the apparent danger of a male hedgehog being poked while mating with a female hedgehog. It states that the closer two people are to each other, the more they may hurt one another. However, this is not an issue for hedgehogs as the male's penis is very near the center of its abdomen (often mistaken for a belly button) and the female has the ability to curl her tail upward to the point that her cloaca protrudes behind the rest of her body. As such, the male doesn't have to get completely on top of the female when mating.

Hedgehogs have a relatively long lifespan for their size (a mouse is 2 years and a large rat is 3-5 years). Larger species of hedgehogs live 4-7 years in the wild (some have been recorded up to 16 years). Smaller species live 2-4 years (4-7 in captivity). Lack of predators and controlled diet contribute to a longer lifespan in captivity.
 

Hedgehog Video

The most common pet species of hedgehog are hybrids of the White-bellied Hedgehog or Four-toed Hedgehog (Atelerix albiventris) and the North African Hedgehog (A. algirus). It is smaller than the West European Hedgehog, and thus is sometimes called the African Pygmy Hedgehog. Other species kept as pets are the Long-eared Hedgehog (Hemiechinus auritus) and the Indian Long-eared Hedgehog (H. collaris).

All three species prefer a warm climate (above 72°F/22°C but below 85°F/29.5°C) and do not hibernate. They eat an insectivore diet. Commonly, this is replaced with cat food and ferret food and is supplemented by insects and other small animals. Today, many pet stores sell hedgehog mixes that are specifically formulated for hedgehogs. Crickets, mealworms, and pinkies (baby mice) are also favored treats. It is illegal to own a hedgehog as a pet in some U.S. states and some Canadian municipalities, and breeding licenses are required. No such restrictions exist in most European countries with the exception of Scandinavia.

The purchase of domesticated hedgehogs has seen a considerable increase in the last few years due to their apparently innocent and playful looks. Hedgehogs are difficult to maintain as pets due to their low resistance to climate and temperature changes, and their inability to adapt to enclosed environments.