The family Erinaceidae family is comprised of early placental mammals, hedgehogs and gymnures, with fossils first observed in the Eocene Epoch. The family is divided into two subfamilies: Erinaceinae (the hedgehogs) and Galericinae (the gymnures and moonrats). There are five extant genera within the Erinaceinae subfamily: Atelerix, Erinaceus, Hemiechinus, Mesechinus, and Paraechinus. Atelerix has four species that range across Africa. Erinaceus also has four species that range from Europe, into the Baltic Peninsula, Middle East, and Eastern Asia. Hemiechinus has two species ranging from North Eastern Africa into Central Asia with one species occurring in India. The genus Mesechinus consist of two species found in Eastern Asia. Lastly, Paraechinus has four species with ranges across Northern Africa and landmasses along the Arabian Sea. The Subfamily Galericinae has five extant genera: Echinosorex, Hylomys, Neohylomys, Neotetracus, and Podogymnura. Within these genera are eight extant species of Gelericinae which are found in regions around the South China Sea including Indonesia, the Philippines, Borneo, and areas near and including the Malay Peninsula. Hedgehogs can be found in a variety of climates and environments while gymnures are primarily found in wet tropical environments. Although hedgehogs are generally the size of mice and small rats, gymnures can be as large as a rabbit. Hedgehogs have become a valuable part of the pet trade, but in certain regions of the world this has led to invasive populations particularly on islands.
Although they are from the same family, hedgehogs and gymnures look very different. The hedgehog’s appearance is defined by the hollow spine-like hairs on their backs which become visible within hours of birth. These spines act as a defense mechanism for the hedgehog that can roll itself into a ball for protection against predators. Although primarily seen as a defense mechanism, research suggests that the spines on hedgehogs can function to absorb impacts such as might be encountered in a fall. Gymnures, also called moonrats, do not have spines but instead emit a foul smell resembling rancid garlic or onion to deter predators. Unlike the hedgehog, they are not exclusively nocturnal and can be considerably larger in size. Despite these differences both subfamilies are known to be good climbers, swimmers, and burrowers. They are also known to have a diverse diet ranging from plants and fruit, to small invertebrates and reptiles. Although they mate up to twice a year, most of their lifetime is spent in solitude.
Ciszek, D. and P. Myers 2000. “Erinaceidae” (On-line), Animal Diversity Web. Accessed February 18, 2015 at http://animaldiversity.org/accounts/Erinaceidae/
The IUCN Red List of Threatened Species. Version 2014.3. . Downloaded on 17 February 2015.
Vincent, Julian FV, and Paul Owers. “Mechanical design of hedgehog spines and porcupine quills.” Journal of Zoology 210.1 (1986): 55-75.
Author: Edward Peebles