Richardson's ground squirrel

Appearance

Typical adults are about 30 centimetres long. Weights vary greatly with time of year and with location: at emergence from hibernation the squirrels weigh between 200 and 400 grams , but by the time they hibernate again this may have risen to nearly 750 grams . Males are slightly larger and heavier than females on average. They are dark brown on the upper side and tan underneath. The tail is shorter and less bushy than in other ground squirrels, and the external ears are so short as to look more like holes in the animal's head. Behavior is more like that of a prairie dog than a typical ground squirrel. The tail is constantly trembling, so the animal is sometimes called the "flickertail".

Naming

This squirrel was named after the Scottish naturalist Sir John Richardson. The Gopher Hole Museum in Torrington, Alberta, Canada, has a large selection of stuffed ground squirrels of many varieties and colors. North Dakota is nicknamed the Flickertail state after the squirrel.

Behavior

Richardson's ground squirrels appear to live communally, but they organize their social structure around female kinship. A female Richardson's ground squirrel will tolerate the presence of closely related females, but are territorial towards other individuals. Individuals are territorial around their nest sites, the burrows of Richardson's ground squirrels are grouped closely together in colonies, and individuals give audible alarm calls when possible predators approach. Recent research has shown that in some cases, ultrasonic alarm calls are given, and are responded to by other members of the colony. Offspring genetically have calls that resemble those of their parents so the adults can pick up on their own offspring's call when danger threatens.

Predators include hawks, weasels, badgers and coyotes.

Habitat

Native to the short grass prairies, Richardson's ground squirrel is found mainly in the northern states of the United States, such as North Dakota and Montana, and in southern Canada, such as southern Alberta and southern Saskatchewan. The range of this animal expanded as forests were cleared to create farm land. They are not simply restricted to prairie; sometimes adapting to suburban environments, causing them to be seen as pests because of the burrows they dig. It is not unusual to find squirrels digging tunnels under the sidewalks and patios of urban homes.

Reproduction

Female Richardson's ground squirrels produce one litter per year. The young, up to 8 in a litter, are born in April or May. Young ground squirrels remain underground in the burrow until they are approximately 30 days old.

Food

These animals are omnivores, eating seeds, nuts, grains, grasses and insects.