ErethizontidaeNew World porcupines

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The Erethizontidae is a family of rodents commonly known as the New World porcupines. The family consists of four genera and twelve species. It is distributed from the Arctic coast of North America to northern Mexico and the Appalachian Mountains, and from southern Mexico to Ecuador and northern Argentina.

Erethizontids are medium-sized to large animals with head and body length from 450 mm ( Echinoprocta) to 860 mm ( Erethizon). Animals of the genus Erethizon weigh up to 18 kg. There is considerable diversity among the four genera of erethizontids with respect to body form. Coendou and Sphiggurus are arboreal animals,with long, spineless, prehensile tails and wide foot pads. Erethizon and Echinoprocta are less arboreal than the other two genera and have short tails (although Erethizon is an excellent climber and may spend a considerable portion of its life in the trees). All have four digits on the forefeet. On the hindfeet, the hallux is reduced in most, but it is relatively large and clawed in Erethizon.

All erethizontids share certain characteristics, such as hairs modified into spines with overlapping barbs; a dental formula 1/1, 0/0, 1/1, 3/3 = 20; flat, rooted, hypsodont cheekteeth with wide reentrant folds (3 labial and 1 lingual on the upper molars, but the anterior and posterior folds soon appear as islands as a result of toothwear). They are hystricognathous and hystricomorphous. Their zygomatic arches are strongly built but the jugal does not contact the lacrimal. The infraorbital canal is huge, and it lacks a secondary groove or canal for nerves and blood vessels. The second and third cervical vertebrae are fused. Erethizontids have enlarged auditory bullae and excellent hearing, but poor vision. Parocciptal processes are short. The olfactory sense of these animals is fairly good.

New World porcupines are nocturnal and generally live solitarily or in pairs. An exception is Erethizon, which is known to shelter with other porcupines in caves during the winter. Erethizontids also den in crude tree nests, rock crevices, brush, logs, and networks of tree roots.

Erethizontids are found in several habitat types: Coendou and Sphiggurus are neotropical and are found in lowland forests; Echinoprocta is found in mountain forests between 800m and 1200m elevation; and Erethizon is found in a variety of vegetative types including coniferous forest, open grassland, desert, canyonland, and riparian associations.

New World porcupines eat primarily plant material; members of the family are known to ingest conifer needles and bark, roots, stems, leaves, berries, meadow grass, seeds, flowers, nuts, aquatic vegetation, fruits, tubers, insects, and small reptiles. Coendou has been known to take fruit and corn from plantations, and Erethizon has earned a bad reputation for killing timber and ornamental trees by stripping bark from the trunks of the trees. It is possible that the perceived damage caused by Erethizon is exaggerated. The meat of Coendou is eaten by South American indians and the quills of Erethizon are used as decoration by some tribes.

Predators of erethizontids include mustelids such as martens, minks, wolverines, ermine, weasels, and fishers. Other predators are red foxes, coyotes, wolves, bear, mountain lions, lynx, bobcats, eagles, and great horned owls. One porcupine predator, the fisher, has been reintroduced to some areas of North America, where it has brought excessively large, damage-causing populations of Erethizon under control.

The geologic range of Erethizontidae is Oligocene to Recent in South America, and late Pliocene to Recent in North America.

References and literature cited:

Feldhamer, G. A., L. C. Drickamer, S. H. Vessey, and J. F. Merritt. 1999. Mammalogy. Adaptation, Diversity, and Ecology. WCB McGraw-Hill, Boston. xii+563pp.

Lawlor, Timothy. 1979. Handbook to the orders and families of living mammals, Mad River Press, Eureka, California, pp185-186.

Macdonald, David. 1984. The encyclopedia of mammals. Facts on File Publications, New York.

Nowak, R. M. and J. L. Paradiso. 1983. Walker's mammals of the world. The Johns Hopkins University Press, Baltimore and London, pp 803-810.

Vaughan, T. A. 1986. Mammalogy. Third Edition. Saunders College Publishing, Fort Worth. vii+576 pp.

Vaughan, T. A., J. M. Ryan, N. J. Czaplewski. 2000. Mammalogy. Fourth Edition. Saunders College Publishing, Philadelphia. vii+565pp.

Wilson, D. E. and D. M. Reeder (eds.). 1993. Mammal species of the world: A taxonomic and geographic reference, 2nd ed.. Smithsonian Institution Press, Washington and London.

Woods, C. A. 1984. Hystricognath rodents. Pp. 389-446 in Anderson, S. and J. K. Jones, Jr. (eds.). Orders and familes of mammals of the world. John Wiley and Sons, New York.

Contributors

Toni Gorog (author), Phil Myers (author), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

motile

having the capacity to move from one place to another.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate