Orbicularis Panniculi
Hedgehogs have a unique muscle, called the orbicularis panniculi, circling their body under the edge of their spiny coat. A frightened hedgehog can roll into a ball and draw the edges of its spine coat together like a drawstring purse, with its head, belly and feet tucked inside. Additional muscles are attached dorsally from the tail to the skull, dividing there into five branches that control the spines on the forehead.

Reproduction
A male courts a female by running in circles around her, twittering, growling and snorting. She may initially ignore him, hiss and snort at him, run away, or curl into a defensive ball. The male persists, and the female eventually positions herself with her rear legs stretched back and her spines flattened. The male has an extra-long penis, so he can avoid being impaled on the female's spines. During copulation he secretes a waxy plug that prevents other males mating with her. After a gestation of 30-40 days, two to 10 young are born. The mother licks them clean and eats the afterbirth, then picks them up in her mouth and guides them to her teats. Newborns are blind, weigh about 0.35 ounces (10 g), and have soft, white spines at birth. Born with edema, their skin is swollen with fluid and covers the soft spines. After a few days, the young reabsorb the excess fluid, exposing the spines. Their eyes open in eight to 18 days. At two weeks they can roll up, and after about six weeks start traveling short distances with their mother. Nursing stops at 40-45 days, and they leave their mother and siblings shortly thereafter. They reach sexual maturity at about 2 months of age.

Life Cycle
Pygmy hedgehogs start foraging at dusk and continue most of the night, then return to their burrows for the day. Solitary and territorial, they enlarge their territories during brief food shortages. On average, they use an area with a radius of 220-330 yards (200-300 m) around shelter found in and under logs, among rocks, under roots of trees and brush piles, in termite mounds and burrows and under buildings. During the dry season when insects are scarce, they aestivate, or become torpid, and live off their stored fat. Their major predators are Verreaux eagle owls, honey badgers, jackals and wild dogs.

Hedgehogs at the zoo are kept off exhibit and used in educational programs. Another small, spiny insectivore, the tenrec, can be seen in the Night Exhibit.

In the mid-1980s, African pygmy hedgehogs became popular in zoos, and then in the pet trade in Europe and the United States. Collecting them from the wild is no longer allowed, but captive-bred animals are legal as pets. They are not truly domesticated, however, even when bred in captivity, and like other exotic animals, can be difficult and expensive to care for. Anyone considering owning an exotic should learn about its needs and be sure it was captive bred. Many more wild-caught animals die than ever reach pet stores, and those that do are often stressed, malnourished and untamable.

These hedgehogs depend on one of the habitats people often refer to as "wastelands." Far from deserving this description, such places support richly diverse communities of plants and animals adapted to challenging conditions. A local example, the sage-steppe of Eastern Washington's Columbia Basin, supports thousands of species, some unique to the area. Lacking timber, significant tourism, or any charismatic threatened species, this ecosystem also lacks strong protections. Every week, more of the sage-steppe disappears under the plow because new irrigation techniques allow farming where it wasn't feasible before. Habitat destruction is a real or potential problem for wildlife in many habitats that appear unproductive.

How You Can Help!
Efforts to save threatened habitats require cooperation and support at international, national, regional and individual levels. You can help in this cause. Learn about and travel to the Columbia basin and other dry habitats. Join and become active in Woodland Park Zoo and other conservation organizations of your choice. Eliminate or reduce pesticide use. Let elected representatives know that all ecosystems have value.

Contact Woodland Park Zoo at webkeeper@zoo.org to find out ways you can support conservation programs at the zoo. Learn other ways you can help conserve wildlife and the habitats they require for survival by visiting our How You Can Help page.

Sources and Suggested Reading
Kingdon, Jonathon. 1984. East African Mammals, Vol. IIA. University of Chicago Press, Chicago, IL. 341 p.

Vriends, Matthew M. 1995. Hedgehogs. Barron's, Hauppauge, NY. 87 p.

* Taxonomic classification varies between references. Classification information used in this fact sheet was taken from Mammal Species of the World: A Taxonomic And Geographic Reference, edited by Don E. Wilson and Dee Ann M. Reeder, Second Edition, 1993.