Forest lemming
| Forest lemming | ||||||||||||
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Forest lemming |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Myopus | ||||||||||||
| Miller , 1910 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Myopus schisticolor | ||||||||||||
| ( Lilljeborg , 1844) |
The wood lemming ( Myopus schisticolor ) is a mammal from the subfamily of the voles (Arvicolinae). The genus Myopus is monotypical with the wood lemming as the only species . The large distribution area of the forest lemming includes the entire Eurasian taiga from Norway in the east to Kamchatka and Sakhalin on the Pacific . The animals prefer old spruce forests with a very thick layer of moss covering the ground . The species is considered harmless.
Mark
The forest lemming is one of the small representatives of the Lemmini tribe , tail and ears are very short. The head-trunk length is 80–125 mm, the tail length 12–20 mm, the length of the hind feet 15–17 mm and the ear length 8–12 mm. The animals weigh 20-45 g. The animals are almost monochrome slate gray, adult individuals have a rust-colored area on their backs. The soles of the hind feet are hairless. Wood lemmings can change the opening of the ear canal with a small flap.
distribution and habitat
The large range of the species includes the entire taiga of Eurasia from Norway to the east to Kamchatka and Sakhalin on the Pacific . In Europe, the area extends in a north-south direction from northern Finland to central western Russia about 300 km west of Moscow . The animals prefer old spruce forests with a very thick, ground-covering layer of moss from species of the genera Hylocomium , Pleurozium , Dicranum and Ptilium . In summer the forest lemming lives in more humid forest areas up to pine-covered moors with distinctive dwarf shrub vegetation and moss bulbs.
Way of life
Wood lemmings are nocturnal. The corridor system and the building are laid out in the moss cushions. The food, which is probably exclusively plant-based, consists mainly of the tips of mosses, preferably of Dicranum spp. The mosses Polytrichum spp., Ptilium crista-castrensis and Pleurozium ssp., While Hylocomium ssp., And Sphagnum ssp. be avoided as far as possible. The animals also eat grasses such as Deschampsia ssp. and the leaves and stems of blueberries ( Vaccinium ). In autumn, forest lemmings store up to 3 liters of moss under dead wood or stones as winter food.
Reproduction and settlement density
Reproduction often begins in winter. Females usually give birth twice a year, rarely three times. The litters include 3–7 young; the litter size is largest in females that have overwintered. The females are sexually mature with 22 to 40 days, males significantly later with at least 44 days. Sexual maturity is only reached at a weight of 20 g; Animals that do not reach this weight during the summer in the year of their birth stop growing over the winter and only become sexually mature in the following spring. The lifespan is rarely more than 12 months.
The species is known for the sex ratio of the young, which deviates strongly from the ratio 1: 1, 75% of the young are females. This excess of females is due to a mutation on the X chromosome (hereinafter referred to as "X *"), which results in females with three different sex chromosome combinations: XX, X * X and X * Y. Females with the latter combination only produce females and have higher levels of reproduction than females of the other two types.
Wood lemmings, like other voles, show cyclical population fluctuations, but gradations occur only very irregularly and rarely, in most years the population density is very low. In gradation years, there is small-scale migration from very densely populated areas to less densely populated areas.
Existence and endangerment
In Finland and Scandinavia , stocks are declining due to the widespread clearing of old spruce forests. Overall, however, the IUCN classifies the species as “least concern”.
swell
literature
- Stéphane Aulagnier, Patrick Haffner, Anthony J. Mitchell-Jones, François Moutou, Jan Zima: The mammals of Europe, North Africa and the Middle East. The destination guide. Haupt, Bern u. a. 2009, ISBN 978-3-258-07506-8 , pp. 194-195.
- Olavi Eskelinen: Studies on the ecology of the wood lemming, Myopus schisticolor (= University of Joensuu, PhD Dissertations in Biology. No. 24, ISSN 1457-2486 ). University of Joensuu, Joensuu 2004, short version (pdf; 510 KB) .
- Anthony J. Mitchell-Jones, Giovanni Amori, Wieslaw Bogdanowicz, Boris Krystufek, PJH Reijnders, Friederike Spitzenberger, Michael Stubbe, Johan BM Thissen, Vladimiŕ Vohralik, Jan Zima: The Atlas of European Mammals. Poyser, London, 1999, ISBN 0-85661-130-1 , pp. 208-209.
Individual evidence
- ↑ The forest lemming on the IUCN Red List, with distribution map
- ↑ in summary: Olavi Eskelinen: Studies on the ecology of the wood lemming, Myopus schisticolor. 2004, p. 7.
Web links
- Myopus schisticolor in the Red List of Threatened Species of the IUCN 2009. Posted by: Henttonen, H., 2008. Accessed on December 15 of 2009.
