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Common Shrew

This article is about the European shrew species. For the mammal known as the Common Shrew in parts of North America, see Cinereus Shrew.

The Common Shrew or Eurasian Shrew, Sorex araneus, is the most common shrew, and one of the most common mammals, throughout Northern Europe, including Great Britain, but excluding Ireland. It is 55–82 millimetres (2.2–3.2 in) long and weighs 5–12 grams (0.2–0.4 oz), and has velvety dark brown fur with a pale underside. Juvenile shrews have lighter fur until their first moult. The Common Shrew has small eyes, a pointed, mobile snout, and red-tipped teeth. It has a life span of approximately 23 months.

Shrews are active day and night, but mostly after dark. They are active most of the time, resting for only a few minutes between burst of activity.

Territory

The Common Shrew is found in the woodlands, grasslands, and hedgelands of Britain, Scandinavia, and Eastern Europe. Each shrew establishes a home range of 370–630 square metres (440–750 sq yd). Males extend these boundaries only during breeding season, to find females. The Common Shrew is extremely territorial and becomes aggressive when another shrew enters its home range. It makes its nest underground or under dense vegetation.[3]

Diet

The shrew's carnivorous and insectivorous diet consists mostly of insects, slugs, spiders, small mice and worms. Shrews need to consume 200-300% of their body weight each day in order to survive. A shrew must eat every two to three hours to achieve this goal. This means that a shrew may starve if it finds no food for as little as 5 hours. They do not hibernate in the winter months because their bodies are too small to hold sufficient fat reserves.[citation needed]

Shrews have poor eyesight, but use their excellent sense of smell and good hearing to locate food. Using these senses, a shrew can locate prey up to 12 centimetres (5 in) deep in the soil.[citation needed]

Breeding

The Common Shrew breeding season lasts from April to September, but peaks during the summer months. After a gestation period of 24 to 25 days, a female gives birth to a litter of five to seven baby shrews. A female usually rears two to four litters each year. The young are weaned and independent by 22 to 25 days.[4]

Breeding is the only time that shrews do not prefer to be solitary. Young shrews often form a caravan behind the mother, each carrying the tail of the sibling in front with its mouth.

Chromosomal polymorphism

The chromosome number (karyotype) of Sorex araneus varies from one individual to another. This is an example of chromosomal polymorphism;[5] the variability occurs as a result of chromosome fusions or disassociations.[6]

Protection and population

The Common Shrew is not an endangered species, but in Great Britain it, like other shrews, is protected from certain methods of killing by the Wildlife and Countryside Act of 1981.[7]

In Britain, shrews can be found at densities up to one per 200 square metres (240 sq yd) in woodlands. The population is controlled by many predators including owls, weasels, stoats, and foxes. A liquid produced by glands on the skin make shrews taste rather unpleasant to domestic cats.[3]

There has been a recent decline in common shrew populations due to increased use of herbicides.[citation needed]

References

  1. ^ Hutterer, Rainer (16 November 2005). Wilson, Don E., and Reeder, DeeAnn M.. ed. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). pp. 283. ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3.
  2. ^ Insectivore Specialist Group (1996). Sorex araneus. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 12 May 2006. Database entry includes a brief justification of why this species is of least concern
  3. ^ a b British Wildlife. London: Collins. 2002. p. 402. ISBN 0 00 713716 8.
  4. ^ "BBC Science and Nature: Animals". http://www.bbc.co.uk/nature/wildfacts/factfiles/260.shtml. Retrieved 11 September 2009.
  5. ^ Polymorphism: when two or more clearly different phenotypes exist in the same interbreeding population of a species. Ford E.B. 1975. Ecological genetics, 4th ed.
  6. ^ White M.J.D. 1973. The chromosomes. Chapman & Hall, London. p169
  7. ^ Wildlife and Countryside Act 1981 S11, Sch 6

External links

v · d · eExtant species of order Soricomorpha
Kingdom: Animalia · Phylum: Chordata · Class: Mammalia · Infraclass: Eutheria · Superorder: Laurasiatheria
 Family Soricidae, subfamily Crocidurinae
Crocidura
(White-toothed
shrews)

Cyrenaica Shrew (C. aleksandrisi) · East African Highland Shrew (C. allex) · Andaman Shrew (C. andamanensis) · C. annamitensis · Ansell's Shrew (C. ansellorum) · Arabian Shrew (C. arabica) · Jackass Shrew (C. arispa) · Armenian Shrew (C. armenica) · Asian Gray Shrew (C. attenuata) · Hun Shrew (C. attila) · Bailey's Shrew (C. baileyi) · Kinabalu Shrew (C. baluensis) · C. cranbrooki · Long-footed Shrew (C. crenata) · Crosse's Shrew (C. crossei) · Reddish-gray Musk Shrew (C. cyanea) · Dent's Shrew (C. denti) · Desperate Shrew (C. desperata) · Dhofar Shrew (C. dhofarensis) · Long-tailed Musk Shrew (C. dolichura) · Doucet's Musk Shrew (C. douceti) · Dsinezumi Shrew (C. dsinezumi) · Eisentraut's Shrew (C. eisentrauti) · Elgon Shrew (C. elgonius) · Elongated Shrew (C. elongata) · Heather Shrew (C. erica) · Fischer's Shrew (C. fischeri) · Greater Red Musk Shrew (C. flavescens) · Flower's Shrew (C. floweri) · Bornean Shrew (C. foetida) · Fox's Shrew (C. foxi) · Southeast Asian Shrew (C. fuliginosa) · Savanna Shrew (C. fulvastra) · Smoky White-toothed Shrew (C. fumosa) · Bicolored Musk Shrew (C. fuscomurina) · Glass's Shrew (C. glassi) · Gmelin's White-toothed Shrew (C. gmelini) · Goliath Shrew (C. goliath) · Peters's Musk Shrew (C. gracilipes) · Large-headed Shrew (C. grandiceps) · Greater Mindanao Shrew (C. grandis) · Grasse's Shrew (C. grassei) · Luzon Shrew (C. grayi) · Greenwood's Shrew (C. greenwoodi) · C. guy · Harenna Shrew (C. harenna) · C. hikmiya · Hildegarde's Shrew (C. hildegardeae) · Hill's Shrew (C. hilliana) · Lesser Red Musk Shrew (C. hirta) · Andaman Spiny Shrew (C. hispida) · Horsfield's Shrew (C. horsfieldii) · Hutan Shrew (C. hutanis) · North African White-toothed Shrew (C. ichnusae) · C. phanluongi · Soricidae, subfamily Crocidurinae (Cont.)

Diplomesodon
Feroculus
Paracrocidura
(Large-headed
shrews)
Ruwenzorisorex
Scutisorex
Solisorex
Suncus

Sylvisorex
(Forest shrews)

 Family Soricidae, subfamily Soricinae
Anourosoricini

Anourosorex
(Mole shrews)

Blarinellini

Blarinella
(Asiatic
short-tailed shrews)

Blarinini

Blarina
(American
short-tailed shrews)

Cryptotis
(Small-eared
shrews)

C. mexicana group

: Mexican Small-eared Shrew (C. mexicana) · Nelson's Small-eared Shrew (C. nelsoni) · C. lacertosus · C. mam · Nectogalini

Chimarrogale
(Asiatic
water shrews)

Episoriculus

Nectogale

Notiosoricini

Megasorex

 Family Soricidae, subfamily Soricinae (Tribe Soricini)
Sorex
(Long-tailed
shrews)

Subgenus
Otisorex

Long-tailed Shrew (S. dispar) · Smoky Shrew (S. fumeus) · Gaspé Shrew (S. gaspensis) · American Pygmy Shrew (S. hoyi) · Large-toothed Shrew (S. macrodon) · Carmen Mountain Shrew (S. milleri) · Dwarf Shrew (S. nanus) · Mexican Long-tailed Shrew (S. oreopolus) · Orizaba Long-tailed Shrew (S. orizabae) · Ornate Shrew (S. ornatus) · Inyo Shrew (S. tenellus) · Verapaz Shrew (S. veraepacis)

S. vagrans complex

: Glacier Bay Water Shrew (S. alaskanus) · Baird's Shrew (S. bairdii) · Marsh Shrew (S. bendirii) · Montane Shrew (S. monticolus) · New Mexico Shrew (S. neomexicanus) · Pacific Shrew (S. pacificus) · American Water Shrew (S. palustris) · Fog Shrew (S. sonomae) · Vagrant Shrew (S. vagrans)

S. cinereus group

: Kamchatka Shrew (S. camtschatica) · Cinereus Shrew (S. cinereus) · Prairie Shrew (S. haydeni) · Saint Lawrence Island Shrew (S. jacksoni) · Paramushir Shrew (S. leucogaster) · Southeastern Shrew (S. longirostris) · Mount Lyell Shrew (S. lyelli) · Portenko's Shrew (S. portenkoi) · Preble's Shrew (S. preblei) · Pribilof Island Shrew (S. pribilofensis) · Olympic Shrew (S. rohweri) · Barren Ground Shrew (S. ugyunak)

Subgenus
Sorex

incertae sedis

 Family Soricidae, subfamily Myosoricinae
Congosorex
(Congo shrews)

Myosorex
(Forest and mouse
shrews)

 Family Talpidae
Scalopinae
(New World moles
and relatives)

Condylura

Parascalops

Scalopus

Scapanulus

Scapanus
(Western North
American moles)

Talpinae
(Old World moles
and relatives)

Parascaptor

Scaptochirus

Scaptonyx

Desmana

Galemys

Dymecodon

Urotrichus

Uropsilinae
(Chinese
shrew-like moles)
 Family Solenodontidae
Solenodon