A North American tree squirrel that rarely comes down from the canopy.

Statistics
Head and body length: 463 to 584mm, Tail length: 195 to 255mm.

Physical description
Abert's squirrel has long and broad ears, with conspicuous tufts. They have grey fur, but are white underneath. The tail is short and wide.

Distribution
From Wyoming, Colorado, New Mexico, Arizona and Utah in the USA to southern Durango in Mexico.

Habitat
Abert's squirrels inhabit ponderosa or yellow pine (Pinus ponderosa) forests.

Diet
Abert's squirrels rely on ponderosa pine as a source of food during the entire year. The inner bark, seeds, buds and flowers are all eaten.They also feed on fungi, carrion and bones. They are reported to bury single pine cones in shallow pits.

Behaviour
Abert's squirrels are strictly diurnal, and are active before sunrise and return to their nests before sunset. They travel frequently from tree to tree, and can jump distances up to 2.4m between trees. During the mating season, several males may chase a female in oestrus for an average of 11 hours. Abert's squirrels build nests in the branches of the pine trees that they live in.

Reproduction
Abert's squirrel breed in April or May. Females give birth to 3-4 young after a gestation period of 40 days. There is often more than one litter per year. The young normally weigh 12g and measure 60mm at birth. The young are weaned at about ten weeks of age, but it is not known at what age they become independent in the wild.

Conservation status
They are not listed by the IUCN Red List 2002.