American water shrew
| American water shrew | ||||||||||||
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Stuffed copy |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Sorex palustris | ||||||||||||
| Richardson , 1828 |
The American water shrew ( Sorex palustris ) is a mammal in the shrew family that is found in North America.
features
| 1 | · | 5 | · | 1 | · | 3 | = 32 |
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The species reaches a total length of 130 to 179 mm and a weight of 7.5 to 17.9 g. Males weighing over 13 g are heaviest during the mating season. At other times of the year there is no size difference between the sexes. The tail length is 61 to 89 mm, the length of the hind feet 16 to 18 mm and the ears 3 to 9 mm long. The summer fur of this shrew is dark gray to gray-brown on the top and silver-gray to white on the underside. In winter there is a blue-black fur on the upper surface, while the belly and the inside of the extremities are colored exactly as in summer. The coat change takes place from August to September and from May to June. The American water shrew has pink to brownish pink hands and feet. At their edges a wreath of stiff hairs happens like the imperfectly formed webbed improve buoyancy.
Like many other shrews, the species has five single-pointed teeth on each side of the upper jaw between the incisor and premolar tooth. Of these, the fifth is only rudimentary.
distribution
The range of this shrew is in mountains as well as in forest areas of North America. The species is absent in the great grassy plains of the continent. It is mainly found in moist habitats that offer sufficient shade. The isolated population in the Appalachians lives at an altitude of 760 to 1150 meters.
Way of life
As the name suggests, the American water shrew mainly lives in the vicinity of water points such as streams, lakes or ponds. It builds a nest from interwoven plant parts, which is hidden in the undergrowth or in underground cavities and has a diameter of about 8 cm. The shrew digs himself or takes over an abandoned beaver den . When females are not ready to mate, each specimen lives alone. The individuals are aggressive when they meet, and sometimes fights occur in which the animals bite each other. In rare cases one of the opponents dies.
The American water shrew can walk shorter distances over the water or surf with the help of surface tension . She swims or dives longer distances. The species primarily hunts insects and other invertebrates . Occasionally it preyes on smaller vertebrates such as fish or frogs . The prey is tracked down mainly through the sense of touch with the vibrissae or with other parts of the body. The American water shrew can also recognize fish from a distance of 12 to 15 cm that are below the surface of the water. It produces sounds that other animals use as biosonar , but it is not clear whether these sounds fulfill the same task. Like many other shrews, the species has an intense metabolism , so it needs its own weight in food every day. The ability to create fat reserves is almost completely absent. Specimens that have captured a larger animal cover it with their own droppings so that no conspecifics steal the prey.
Females have 2 or 3 litters between February and August, with 3 to 10 offspring per litter. The young animals reach sexual maturity next spring. The enemies of this shrew include owls , other birds of prey , weasels , otters , snakes and predatory fish. Only a few specimens reach an age of 18 months.
status
The American water shrew is listed by the IUCN due to its wide distribution in the category not endangered (least concern). Locally, individual stands can be threatened by the loss of moisture habitats as a result of drainage. The species is present in several nature reserves.
Individual evidence
- ↑ Don E. Wilson , DeeAnn M. Reeder (Ed.): Mammal Species of the World . A taxonomic and geographic Reference . 3. Edition. 2 volumes. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 (English, Sorex palustris ).
- ↑ a b c d e f Naughton, Donna (Ed.): The Natural History of Canadian Mammals . University of Toronto Press, 2012, ISBN 978-1-4426-4483-0 , pp. 278-280 (English, Sorex palustris ).
- ↑ a b c d e f g Sorex palustris in the endangered species Red List of IUCN 2016. Submitted By: Cassola, F., 2016. Retrieved on 28 December 2016th