Types of Rodents
Rodents (Rodentia), the largest order of mammals in the world, account for approximately forty percent of the world's mammal species.
The two hundred plus North American rodent species account for approximately sixty percent of the total North American land animal species diversity.
The order includes commonly known mammals such as rats, mice and squirrels, plus other mammals such as prairie dogs. Formally, the North American population breaks down into eight families and two hundred and six species:
- Muridae (rats and mice): The 81 documented Muridae species, makes them the most common North American rodents. The meadow vole pictured above, also known as a field mouse, inhabits a variety of grasslands and prairies. As many rural homeowners know from experience, they are also known to roam indoor structures when given the opportunity.
- Sciuridae: The 67 documented Sciuridae species makes them the second most common North American rodents. Despite the less than stellar reputation of most rodents, some, such as squirrels and chipmunks, appeal to certain portions of the human population.
Picture two shows a Mexican Ground Squirrel (Spermophilus mexicanus), native to areas of the Southwest. The squirrel pictures link points to a multi-page series covering additional North American squirrel species.
- Heteromyidae: Better known as kangaroo rats, kangaroo mice and rock pocket mice, 37 separate Heteromyidae species inhabit the grassland areas, primarily in western North America.
- Geomyidae: While the name gopher gets applied to many ground squirrels, formally the name applies to species in the Geomyidae family, also called pocket gophers. They are new world rodents, with 14 documented North American species.
- Dipodidae: Large hind feet and/or legs differentiate the 4 native Dipodidae, or jumping mice species. The Preble's meadow jumping mouse (Zapus hudsonius preblei) is listed as endangered under the terms of the Endangered Species Act.
- Castoridae: The American Beaver (Castor canadensis) represents the 1 North American beaver species.
- Erethizontidae: The Porcupine represents the 1 North American Erethizontidae species.
- Aplodontidae: Called the mountain beaver, Aplodontia rufa, is not actually a beaver, but a Western forest rodent, similar to a ground hog. In a category of its own, Aplodontia rufa represents the entire Aplodontidae family.
All rodents share the common physical characteristic of two sets of incisors (top and bottom), used for chewing on stuff.
Over the centuries rodents have been characterized as pests, introducing disease and wrecking havoc on food stocks where they roam. Other rodents such as hamsters have been domesticated as pets.
© 2010-2012 Patricia A. Michaels