A large water vole, this rodent is about a foot long with thick, silky fur and a naked, eight to 11 inch tail flattened on the side. The sexes are similar in size and weigh from 2 to 4 pounds. Most muskrats in Arizona are rusty reddish brown in color; young animals are darker than the adults, some being nearly black. Although the muskrat is highly adapted to an aquatic existence, its hind feet, while comparatively large, are not webbed like those of a beaver's.
Muskrats can be found along most of Arizona's perennial rivers and permanent marshes. Although they forsake most small streams, they can also be found along dirt-lined canals. Never particularly abundant other than locally (e.g., Montezuma Well and Peck's Lake off of the Verde River), muskrats have disappeared from some areas (e.g., the San Pedro River) and invaded others.
Primarily a vegetarian, the muskrat feeds on aquatic grasses, pondweed, cattail roots, and the leaves of seep willows. Although many muskrats live in bank burrows, these animals also construct distinctive conical houses of shredded cattails and other marsh vegetation in quiet waters. These dens, which may serve as feeding areas, shelter areas, or nursery sites are all entered through submerged passageways. The nursery dens are the most elaborate, typically consisting of several chambers some of which are lined with grass and soft vegetation.
Muskrats in Arizona are reported to breed during every month of the year, but most of the young are born between March and October. The usual litter size is five or six.
Hunting and Trapping History
Muskrats have never been an important fur animal in Arizona. The number trapped since the late 1980s has been virtually zero.