GYMNURES AND HEDGEHOGS: Erinaceidae

PHYSICAL CHARACTERISTICS

Gymnures and hedgehogs are generally small, pointy-snouted animals covered with fur, or in the case of hedgehogs, with spines. Each of their four, short legs ends in a flat, walking foot with five toes. In a few African hedgehogs, the big toe is small or nearly nonexistent (not there).

Overall, this group ranges from 4 to 18 inches (10 to 46 centimeters) in body length plus tails from 0.4 to 12 inches (1 to 30 centimeters), and weighs from 0.5 ounces to 4.4 pounds (15 to 2,000 grams). Most members of this group have bodies about 4 to 6 inches (10 to 15 centimeters) long, and short, sometimes barely noticeable tails. A few, however, have longer tails and larger bodies. For example, the Madagascar hedgehog has a grasping tail that can be more than two times the length of its body. The Malayan moonrat is the largest member of this family. With a body that can reach 16 to 18 inches (41 to 46 centimeters) long and a tail that stretches up to 8 to 12 inches (20 to 30 centimeters) long, this animal can measure more than 2 feet (0.6 meters) long from snout to tail tip and weigh up to 4.4 pounds (2 kilograms).

GEOGRAPHIC RANGE

Gymnures and hedgehogs are found in parts of Africa, Eurasia, central Asia, and southeast Asia. New Zealand is also home to a healthy population introduced by humans. Hedgehogs tend toward the cooler climates, while gymnures and moonrats demand tropical and subtropical areas.

HABITAT

Members of this family thrive in a number of varying habitats on land, usually living and feeding at ground level and, in some species, in burrows. A few, like the moonrat, may take an occasional swim in the water. Gymnures prefer humid forests, while hedgehogs can live in a dry and rocky desert, a busy city park, or a mountainside meadow. In fact, hedgehogs can survive almost anywhere they can find food during their night-time hunts and sheltered hideaways for their daytime slumber.

DIET

The diet of hedgehogs and gymnures can include a variety of things, but they mostly eat insects, spiders, worms and other invertebrates, animals without backbones. If they are big enough to kill a reptile, amphibian, or a small mammal, they will do so once in a while. Sometimes they will also eat fungi or fruit. In addition, hedgehogs often prey on birds' eggs. They spend most of their active hours either looking for food or eating it.

BEHAVIOR AND REPRODUCTION

Most members of this family are nocturnal, active only at night. Some species, like the lesser gymnure, may venture out in the daytime if they become hungry enough, but they usually spend their days resting in a sheltered spot. In the winter, many cold-climate species have the ability to slow their body processes, and essentially enter a deep sleep known as hibernation until the weather warms. The European hedgehog sometimes hibernates for six or seven months, surviving on body fat it stored when it was active earlier in the year. Warm-climate species do not have to contend with bitter winters, but they do sometimes face extended dry periods, or droughts, when food can become scarce. During droughts, many will enter a deep sleep, called estivation (est-ih-VAY-shun), which is similar to hibernation.

Adult gymnures and hedgehogs typically live alone. They protect a territory by marking its edges with often-powerful scents and by threatening other adults to stay away with raspy hisses. If a predator approaches, hedgehogs take on a defensive posture by rolling into a ball and standing their spines on end—turning themselves into living pin cushions. Gymnures have no spines for protection and instead try to stay out of sight of predators as often as possible, hiding beneath piles of branches or leaves, among tree roots, or sometimes in burrows dug by other animals.

Adult gymnures and hedgehogs give up their solitary existence during mating periods, and the females welcome males with the same types of hisses they used earlier in the year to scare them away from their territories. Because of their spines, hedgehog mating can be tricky. To accomplish it, the female smoothes down her spines, so the male can approach without being hurt. After mating, the male leaves and returns to his solitary life. Females, on the other hand, must care for the two to five, blind and helpless babies now living in the nest. The young stay with the mother for five to seven weeks until they are ready to survive on their own.

GYMNURES, HEDGEHOGS, AND PEOPLE

The most intense relationships between people and this family surround the hedgehogs. Gardeners often consider a hedgehog in the yard a helpful addition that will suppress insect and spider numbers. On the other hand, poultry farmers dislike hedgehogs, which are quite fond of eggs and will occasionally eat a chick.

Superstitions in some cultures view a hedgehog as a good omen, and some folk remedies call for the use of blood or some other part of a hedgehog. Historically, hedgehogs have also been killed for their meat, and for their spines to use to comb newly cut sheep wool.

AN ODD HEDGEHOG BEHAVIOR

A particularly odd behavior among the hedgehogs—and one that is still not fully understood—is called "self-anointing." It happens when a hedgehog comes across a powerful odor. The animal stops what it is doing, and begins licking and sometimes even chewing the source of the odor until it starts to foam at the mouth. Next, it smears the foam over its body spines with small backward jerks of its head and flicks of its tongue. Although many people have seen hedgehogs perform this ritual, scientists still are not sure exactly why animals do it.

CONSERVATION STATUS

Seven species of this family are at some risk, according to the World Conservation Union (IUCN). The dwarf gymnure is Critically Endangered, facing an extremely high risk of extinction in the wild. In addition, three species are Endangered, facing a very high risk of extinction in the wild, and two species are Vulnerable, facing a high risk of extinction in the wild. In addition, one is considered Near Threatened, not currently threatened, but may become so. Many of these species live in small areas, and human activities like logging and new farms are destroying their limited habitats.

WESTERN EUROPEAN HEDGEHOG (Erinaceus europaeus): SPECIES ACCOUNTS

Physical characteristics: Western European hedgehogs are round-to oval-shaped and mostly brown. Their most recognizable feature is the layer of light-yellow and brown spines on their backs. They have small, but noticeable rounded ears, fairly long snouts, and dark, beady eyes. Their body ranges from 9 to 11 inches (23 to 28 centimeters) long with short tails of 0.5 to 1.2 inches (1.5 to 3 centimeters) long. The adult weight can vary from 14 to 42 ounces (400 to 1,200 grams).

Geographic range: Western European hedgehogs are found in Western and central Europe from Scandinavia, northern European Russia, Britain and Ireland to Italy and the Mediterranean islands. A population introduced by humans in New Zealand is also thriving.

Habitat: People most frequently see western European hedgehogs in farmlands, parks and gardens, but the animals are also quite common in forests and meadows where they are less likely to encounter humans.

Diet: Active at night, these hedgehogs primarily eat insects, worms, spiders and other invertebrates, but they will also prey on eggs and fruit. In captivity or when otherwise fed by humans, they will eat just about anything from dog food to bread.

Behavior and reproduction: They do not set up territories like some other insectivores, but adults still live alone. Those in cooler climates survive the winter by hibernating for four to seven months. Mating occurs from spring to summer, and females usually have four to six babies, although they sometimes have as few as two or as many as ten at a time. The babies are blind, naked, and helpless, and remain in the mother's nest for no more than six weeks, then they are pushed out to face the orld on their own.

Western European hedgehogs and people: Hedgehogs are becoming increasingly popular as pets. Most human contact with the animals, however, comes from positive encounters in the yard. Homeowners generally welcome the hedgehogs, which have a taste for insects and spiders that homeowners view as pests.

Conservation status: Western European hedgehogs are not threatened. ∎

MALAYAN MOONRAT (Echinosorex gymnura): SPECIES ACCOUNTS

Physical characteristics: Malayan moonrats have long and narrow bodies, coarse hair, pointy snouts and long, almost naked tails giving them an appearance that resembles a Virginia opossum. They have mostly black fur toward the back and white fur toward the head, although they may have quite large, black patches on the head. Sometimes they are completely white. Malayan moonrats range from 10 to 18 inches (26 to 46 centimeters) in body length, plus a 6.5- to 12-inch (16.5- to 30-centimeter) tail. Adult weight varies from about 1 to 3 pounds (0.45 to 1.4 kilograms), but can sometimes reach 4.4 pounds (2 kilograms). Males are generally a bit smaller than females.

Geographic range: Malayan moonrats are found on the Malay Peninsula, Sumatra, and Borneo.

Habitat: Moist forests, mangrove swamps, and wet farmlands are the typical habitats of Malayan moonrats. Scientists believe the animals spend at least part of their time in the water.

Diet: An animal of the night, Malayan moonrats eat worms, insects, crabs, and other invertebrates found in moist areas. They will also eat fruit, and occasionally frogs or fish.

Behavior and reproduction: When they are not looking for food at night, Malayan moonrats rest in hiding places among tree roots, inside hollow logs, or in other tight spaces. Adults live alone. They release strong odors to mark the edges of their territories and warn other moonrats to stay away with threatening hisses. They also release odors to ward off predators. When they are preparing to have young, they will make nests mostly from leaves. Females usually have two babies at a time, either once or twice a year. Scientists know little more about moonrat adults or young.

Malayan moonrats and people: Generally speaking, Malayan moonrats leave people alone, and people leave them alone.

Conservation status: Malayan moonrats are not threatened. ∎

FOR MORE INFORMATION

Books:

McDonald, D. Collins Field Guide: Mammals of Britain and Europe. London: Harper Collins, 1993.

Nowak, Ronald M. Walker's Mammals of the World Online. Baltimore: John Hopkins University Press, 1995. http://www.press.jhu.edu/books/walkers_mammals_of_the_world/insectivora/insectivora.erinaceidae.echinosorex.html (accessed on July 1, 2004).

Reeve, N. Hedgehogs. London: Poyser Natural History, 1994.

Web sites:

"European hedgehog." BBC. http://www.bbc.co.uk/nature/wildfacts/factfiles/193.shtml (accessed on July 1, 2004).

"European Hedgehog." Boreal Forests of the World Mammal Species. http://www.borealforest.org/world/mammals/hedgehog.htm (accessed on July 1, 2004).

IUCN Red List of Threatened Species—Species Information. http://www.redlist.org (accessed on July 1, 2004).