Northern red-backed vole

Polarrötelmaus ( Myodes rutilus )

The Polarrötelmaus ( Myodes rutilus ) is a vole, which is assigned to the genus Rötelmäuse ( Myodes ).

Features

With a head -body length of eight to eleven centimeters, the Polarrötelmaus is similar in size to the bank vole ( Myodes glareolus ). The length of her hairy tail is two to four centimeters of generally less than 40 percent of the body length, and thus shorter than in the bank vole. About the tail end of which projects a striking, existing from overhanging brush Endhaaren, five to eight millimeters. The back of the coat Polarrötelmaus is significantly redder than that of the bank vole. The flanks are yellowish gray. The ears are medium to large with eleven to 16 millimeters. Grown Polarrötelmäuse weigh ten to 30 grams.

Reproduction

The propagation of Polarrötelmäuse takes place from early May to late September. At too high a population density of breeding period will already be finished in mid-summer. The females from the first two litters already participate mostly in reproduction. Due to the efforts that are associated with it, these animals do not survive the fall. Nor the females from the previous year who die after up to three litters. The females from the later litters overwinter and multiply until the following year. The first litter is usually smaller than the following. Usually five to seven young are born.

Dissemination

The distribution of Polarrötelmaus extends into the northern Holarctic from northern Fennoscandia (Norway, Sweden and Finland) over Siberia and Alaska to Canada. In the Eurasian part of the range, the southern limit of distribution shifts from west to east further south. While the northern limit of distribution remains almost on the same latitude. In eastern Asia, the distribution area on Sakhalin and Hokkaido with a north- Südausdehung from 43 to 73 Latitude has the largest width.

In some areas, the Polarrötelmaus appears together with the bank vole ( Myodes glareolus ). While in the south of the common areas of distribution dominates the bank vole, the ratio shifts in favor of the north Polarrötelmaus. In the common areas of distribution with the Graurötelmaus ( Myodes rufocanus ), the Polarrötelmaus is so strongly dominated by the Graurötelmaus that Polarrötelmaus adjusts the reproduction at high Graurötelmausdichte. Only when the Graurötelmausdichte decreases in late summer, the reproduction in the Polarrötelmaus continues.

As the preferred habitat Polarrötelmaus meso- and eutrophic grass - and herb -rich forests. North of the border spruce differs from the Polarrötelmaus on lichen -rich pine forests. In the coniferous forests it prefers moss -rich locations. In marshes, fields or in beats it is rare to find. The Polarrötelmaus digs hardly transitions, but preferably naturally occurring hiding places.

Nutrition

In comparison with the other Rötelmausarten the Polarrötelmaus clearly eats more seeds and less bark and green parts of plants. From berries and the seeds contained in the Polarrötelmaus only eats the flesh and the seeds inside. The fruit and seed shells they spurned. In winter climbs the Polarrötelmaus trees and bushes and eats there buds and lichens. As the winter stock Polarrötelmaus collects seeds, for example by Melampyrum species ( cow-wheat ).

Natural enemies

Like many other small mammals, the Polarrötelmaus a popular prey for many predators dar. Therefore, it is nocturnal in the time of day-night shift. During continuous light in the arctic midsummer, see polar day, occur throughout the day on waking.