Squirrels are one of these animals, which in the harvest year, multiply very quickly.
In natural conditions, they breed twice a year. The number of small calves is from 2 to 12 in each litter. The number of births depends on the living conditions of the squirrel. Breeding season, depending on latitude, feeding conditions, and population density, starts in late January – early March and ends in July-August.
The squirrel builds a nest using thin branches for the outer frame. And from the inside, it creates a thick layer of moss and dry grass. The nest chamber is lined with soft straw and wool of different animals. The entrance to the squirrel’s nest is covered with moss. Even in severe frosts, such a building can keep warm.
Pregnancy lasts 35-38 days, in a litter of 3 to 10 cubs; in the second litter is less. Newborn squirrels are naked and blind, weighing about 8 g.
Their hair cover appears on the 14th day, they get their sight only on 30-32 days. From this moment on they begin to leave the nest.
During the lactation period, the females are forced to eat more because of the increased calorie demand. At this time, they are actively feeding and are more likely to be seen by predators. The worst enemy of protein is the marten. After the calves stop feeding with milk, the mother or father will bring them food for a few more days. Then parents give the young generation to themselves. The study of proteins revealed that the number is affected by the action of intra-population mechanisms of self-regulation.
The color of animals in late autumn is dark gray.