Order: Rodents (Rodentia)
Family: Squirrels (Scuiridae)
Habitat: mountain forests of Beringia, northwest of North America.
Similarly to many other rodents, various squirrels, including North American red squirrel (Tamiasciurus hudsonicus) have rather safely gone through the period of anthropogenous pressure at the end of Holocene. Climatic changes which had shifted southern border of coniferous forests zone farther to the south appeared very favourable for this species.
But the ice age is a temporary phenomenon, and after thawing of glacier various deciduous trees had started to spread to the north, having pushed coniferous forests of North America closer to polar areas, and also to the west, to Beringia. The part of the population of American red squirrel had receded to these forests where had evolved to new species – to Beringean mountain squirrel.
Beringean mountain squirrel is rather large rodent – males weigh 350 – 400 grams, females up to 300 – 350 g. It grows up to 25 – 30 centimeters long with fluffy tail of the same length. On body fur is also longer and fluffier, rather than at ancestor, even in summer because of colder climate in their inhabitancy – northern and mountain (even high-mountainous) coniferous forests.
As against the ancestor, Beringean mountain squirrel is not red, and most likely bluish-gray, like a color of stones and dark needles of trees in its inhabitancy; also it has kept lighter belly, characteristic for its ancestor, and white rings around of eyes have increased to large light spots on cheeks. On ears of these squirrels short signal brushes of darker color grow, and at sexually mature males also there is a dark strip along back; occasionally there are melanistic individuals.
Beringean mountain squirrel is easily adapting animal with diverse diet. It eats seeds of many species of coniferous trees, also some berries, mushrooms, various insects and spiders, and ravages nests of small birds. This species equally freely feels like both on trees, and on the ground therefore it has superseded from northwest of North America various chipmunks conceding to Beringean mountain squirrel in force and quickness.
This squirrel lives on trees where it builds a typical squirrel drey of branches of conifers, or occupies empty bird nest, reconstructing it as it needs. From within this drey is warmed by female’s underfur, and in spring female gives birth up to 5 – 6 blind and helpless cubs; she brings them up alone and looks after them within 2 months. Elder cubs remain with mother, but study to search for food and to escape from enemies. At the age of 5 months squirrel cubs become independent and leave her, and to one-year-old age they become sexually mature. While female looks after posterity, male stays in her territory, gathering food and feeding up the female. When cubs leave drey, male joins family. When the posterity leaves the female, male also goes away from female’s territory.
Beringean mountain squirrel is sociable enough animal. Breeding pairs living in neighbourhood relate to each other loyally enough, but in courtship period between solitary males rather severe fights break out, accompanied by very painful bites and long pursuits in tree crones.
If Beringian mountain squirrel will be eaten by nobody (and it is a prey of various small and medium-sized predatory mammals and birds of coniferous forests in mountains of Beringia), it can live up to 7 – 8 years.
To the east from Beringia, in northern forests of North America the species related to Beringean mountain squirrel lives – taiga squirrel (Tamiasciurus borealis). It differs from the mountain relative in more habitual red color of wool, but in the rest it is practically similar to previous species. Only white marks on its head are larger, and wool on stomach is snow-white.
This species of mammals was discovered by Bhut, the forum member.