Arizona Cotton Rat

The Arizona cotton rat or Colorado River cotton rat (Sigmodon arizonae) is a rat in the family Cricetidae. It is found in the southwestern United States and northwestern Mexico. == Description == The Arizona cotton rat has a typical rat-like appearance, and is sufficiently similar to the hispid cotton rat that it was considered to be part of the same species until 1970, when genetic analysis confirmed its distinct nature. It has bristly brownish fur over most of its body, with whitish underparts and grey feet. The scaly tail is dark in color, with very sparse fur. Adults range from 9.8 to 14.2 inches (250 to 360 mm) in total length, including the 3.9 to 5.9 in (99 to 150 mm) long tail, and weigh anything from 2.9 to 10.6 ounces (82 to 301 g). Males are slightly larger than females, but the two sexes are otherwise similar in appearance. Females have ten or twelve teats, suggesting a maximum litter size of around this number. Reproduction is thought to occur year-round. == Distribution and habitat == The Arizona cotton rat is found in southern and central Arizona, the extreme southwestern corner of New Mexico, and in western Mexico from Sonora…