Squirrels are rodents of the family Sciuridae, which includes species such as chipmunks, ground squirrels and marmots. Approximately 285 species of squirrel have been found worldwide, from the Americas to Eurasia and Africa. In Canada there are 23 native species. We'll look just at squirrels native to Alberta, of which there are seven. Squirrels are small- to medium-sized terrestrial rodents. They fall into three categories: Tree squirrels Tree squirrels are characterized by bushy tails and small feet. Unlike most mammals, they can descend trees headfirst. They do so by rotating their ankles 180 degrees, allowing their hind feet to point backward up the tree and grip the bark from the opposite direction! Tree squirrels remain active year-round and do not hibernate. Tree squirrels frequently build nests, called dreys, in trees. Alberta is home to one species of tree squirrel, the American Red Squirrel. Flying squirrels Flying squirrels are a subset of tree squirrels that have a skin fold along their flanks connecting their forelegs with their hind legs. This membrane allows them to glide between trees. Flying squirrels are also the only nocturnal squirrel species in Canada. Alberta is home to one species of flying squirrel, the Northern Flying Squirrel. Ground-dwelling squirrels Ground-dwelling squirrels typically have less bushy tails and more robust hind feet. Ground squirrels and chipmunks are known for their ability to carry food in internal cheek pouches. Ground-dwelling squirrels typically hibernate or enter torpor during the winter and dig burrows for shelter and food storage. Of the seven species of squirrel found in Alberta, five of them are ground squirrels. Squirrels can be found throughout Canada. Certain species, such as the American red squirrel, are widespread in boreal and mixed forests in all provinces and territories. In Canada, most species of squirrel reproduce once annually. Gestation typically lasts 24–44 days, and litters average three to eight young, depending on the species. At birth, the young are hairless and poorly developed, but their growth is rapid. Squirrels are primarily herbivorous, mostly relying on green vegetation, nuts, seeds, bulbs and buds. However, most squirrels will gladly eat insects and eggs, as well as small birds and mammals. Many species of trees (e.g., beech, maple, spruce) will synchronize their seed production in what is known as a mast year in an attempt to flood the ecosystem with so many seeds that the seed predators like squirrels are unable to eat them all, so that some tree seeds will make it to germination. Squirrels hoard food for a later time. Some species, like the Eastern gray squirrel and the fox squirrel, are scatter-hoarders and will bury seeds and nuts all around their home range. Others, like the red squirrel, are larder-hoarders and will cache cones and other food items in mounds within their territory. By burying or hoarding seeds across the forest and frequently not returning to eat those seeds, they plant countless trees every year, helping the forest regenerate. Squirrels are eaten by most medium-to-large predators in the areas they inhabit. While very fast, they can make up a significant portion of the diet of foxes, lynx, weasels, otters, martens, wolverines, rattlesnakes and various birds of prey. In certain areas, squirrels, especially ground squirrels, are also hunted by humans. As cities have encroached on natural spaces, many species of squirrels, most notably the Eastern gray squirrel, have learned to thrive in urban environments, losing much of their fear of humans. Lets look at the seven species of squirrel found in Alberta: Columbian Ground Squirrel Golden-mantled Ground Squirrel Richardson’s Ground Squirrel Thirteen-lined Ground Squirrel Franklin’s Ground Squirrel American Red Squirrel Northern Flying Squirrel Resources HTML, graphics & design by Bill Willis 2025