Shrew
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2008-07-16T16:58:06Z
Anaxial
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[[WP:UNDO|Undid]] implausible and uncited claim by [[Special:Contributions/148.166.13.194|148.166.13.194]] ([[User talk:148.166.13.194|talk]])
{{redirect|Shrews|the fictional characters in ''The Animals of Farthing Wood''|The Shrews}}
{{Taxobox
| name = Shrews<ref name=msw3>{{MSW3 Hutterer | pages = 223-300}}</ref>
| fossil_range = Middle [[Eocene]] to Recent
| image = southern short-tailed shrew.jpg
| image_width = 250px
| image_caption = [[Southern Short-tailed Shrew]]
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Mammal]]ia
| ordo = [[Soricomorpha]]
| familia = '''Soricidae'''
| familia_authority = [[Johann Fischer von Waldheim|G. Fischer]], 1814
| subdivision_ranks = [[Subfamily|Subfamilies]]
| subdivision =
[[Crocidurinae]]<br>
[[Myosoricinae]]<br>
[[Soricinae]]
}}
'''Shrews''' are small, superficially mouse-like [[mammal]]s of the [[Family (biology)|family]] '''Soricidae'''. Although their external appearance is generally that of a long-[[nose]]d [[mouse]], the shrews are not [[rodent]]s and not closely related: the shrew family is part of the [[order (biology)|order]] [[Soricomorpha]]. Shrews have feet with five clawed toes, unlike [[rodent]]s, which have four. Shrews are also not to be confused with either [[treeshrew]]s or [[elephant shrew]]s, which belong to different orders.
Shrews are distributed almost worldwide: of the major temperate land masses, only New Guinea, Australia, and New Zealand do not have native shrews at all; [[South America]] has shrews only in the far-northern tropics, including [[Colombia]]. In terms of species diversity, the shrew family is the fourth most successful of the mammal families, being rivalled only by the [[Muroidea|muroid]] families [[Muridae]] and [[Cricetidae]] and the [[bat]] family [[Vespertilionidae]].
==Characteristics==
All shrews are small, most no more than mouse size. The largest species is the [[House Shrew]] (''Suncus murinus'') of tropical Asia which is about 15 cm long and weighs around 100 grams{{fact|date=November 2007}}; several are very small, notably the [[Etruscan Shrew]] (''Suncus etruscus'') which at about 3.5 cm and 2 grams is the smallest living terrestrial mammal.
In general, shrews are terrestrial creatures that forage for seeds, insects, nuts, worms and a variety of other foods in leaf litter and dense vegetation, but some specialise in climbing trees, living underground, in the [[Subnivean|subniveal layer]] or even hunting in water. They have small eyes, and generally poor [[Visual perception|vision]], but have excellent senses of [[hearing (sense)|hearing]] and [[olfaction|smell]].<ref name=EoM>{{cite book |editor=Macdonald, D.|author= Barnard, Christopher J.|year=1984 |title= The Encyclopedia of Mammals|publisher= Facts on File|location=New York|pages= 758-763|isbn= 0-87196-871-1}}</ref> They are very active animals, with voracious appetites and unusually high [[metabolic rate]]s. Shrews must eat 80-90 per cent of their own body weight in food daily. They are not able to [[hibernation|hibernate]].
Whereas rodents have gnawing [[incisor]]s that grow throughout life, the teeth of shrews wear down throughout life, a problem made more extreme by the fact that they lose their [[milk teeth]] before birth, and therefore have only one set of teeth throughout their lifetime. Apart from the first pair of incisors, which are long and sharp, and the chewing [[Molar (tooth)|molar]]s at the back of the mouth, the teeth of shrews are small and peg-like, and may be reduced in number. The [[dentition|dental formula]] of shrews is:{{dentition2|3.1.1-3.3|1-2.0-1.1.3}}
Shrews are fiercely territorial, driving off rivals, and only coming together to mate. Many species dig [[burrow]]s for caching food and hiding from predators, although this is not universal.<ref name=EoM/>.
Female shrews can have up to ten litters a year, and the animals only stop breeding in the winter in temperate zones, and breed all year round in the tropics. Shrews have a [[gestation]] period of 17–32 days. The female often becomes pregnant within a day or so of giving birth, and [[lactation|lactates]] during her pregnancy, [[weaning]] one litter as the next is born<ref name=EoM/>. Shrews live for between 12 and 30 months.<ref>{{cite book
| last = Macdonald (Ed)
| first = Professor David W.
| authorlink =
| coauthors =
| title = The Encyclopedia of Mammals
| publisher = Oxford University Press
| date = 2006
| location =
| pages =
| url =
| doi =
| isbn = 0-19-920608-2 }}</ref>
Shrews are unusual among mammals in a number of respects. Unlike most mammals, some species of shrew are [[venom (poison)|venomous]]. Also, along with the [[bat]]s and [[toothed whale]]s, some [[echolocating shrews|species of shrew]] use [[animal echolocation|echolocation]]. Unlike most other mammals, shrews also do not have a [[zygomatic bone]].
Shrews hold nearly 10% of their mass in their brain, a relatively high [[brain to body mass ratio]].<ref>[http://www.kk.org/thetechnium/archives/2004/11/brains_of_white.php Brains of White Matter]</ref>
===Echolocation===
[[Image:NShortTailedShrew23.jpg|thumb|right|The [[Northern Short-tailed Shrew]] is known to echolocate]]
The only terrestrial mammals known to [[animal echolocation|echolocate]] are two genera (''[[Sorex]]'' and ''[[Blarina]]'') of shrews and the [[tenrec]]s of [[Madagascar]]. These include the [[Vagrant Shrew]] (''Sorex vagrans''), the [[Common Shrew|Common or Eurasian Shrew]] (''Sorex araneus''), and the [[Northern Short-tailed Shrew]] (''Blarina brevicauda''). The shrews emit series of ultrasonic squeaks. In contrast to bats, shrews probably use echolocation to investigate their habitat rather than to pinpoint food{{fact|date=November 2007}}.
==Classification==
There are 376 species of shrew in 26 genera, which are grouped into three living subfamilies: [[Crocidurinae]] ([[white-toothed shrew]]s), [[Myosoricinae]] (African white-toothed shrews) and [[Soricinae]] ([[red-toothed shrew]]s). In addition, the family contains the extinct subfamilies [[Limnoecinae]], [[Crocidosoricinae]], [[Allosoricinae]] and [[Heterosoricinae]] (although Heterosoricinae is also commonly considered a separate family).
*'''Family Soricidae'''
**Subfamily [[Crocidurinae]]
***''[[Crocidura]]''
***''[[Diplomeson]]''
***''[[Feroculus]]''
***''[[Paracrocidura]]''
***''[[Ruwenzorisorex]]''
***''[[Scutisorex]]''
***''[[Solisorex]]''
***''[[Suncus]]''
***''[[Sylvisorex]]''
**Subfamily [[Myosoricinae]]
***''[[Congosorex]]''
***''[[Myosorex]]''
***''[[Surdisorex]]''
**Subfamily [[Soricinae]]
***Tribe [[Anourosoricini]]
****''[[Anourosorex]]''
***Tribe [[Blarinellini]]
****''[[Blarinella]]''
***Tribe [[Blarinini]]
****''[[Blarina]]''
****''[[Cryptotis]]''
***Tribe [[Nectogalini]]
****''[[Chimarrogale]]''
****''[[Chodsigoa]]''
****''[[Episoriculus]]''
****''[[Nectogale]]''
****''[[Neomys]]''
****''[[Nesiotites]]''
****''[[Soriculus]]''
***Tribe [[Notiosoricini]]
****''[[Megasorex]]''
****''[[Notiosorex]]''
***Tribe [[Soricini]]
****''[[Sorex]]''
== Metaphorical usage ==
In the [[English language]], the word shrew is also used to describe a woman with a violent, scolding, or nagging temperament, as in [[Shakespeare]]'s play ''[[The Taming of the Shrew]]''. The animals were believed historically to behave aggressively and with cruelty, and to have a poisonous bite; the term "shrew" was then applied to a person thought to have a similar disposition.<ref>[[Stefan Buczacki]], ''Fauna Britannica'', 2002, ISBN 0-600-61392-5</ref>
''Shrew'' was one of the names originally proposed for the British Fighter Airplane which finally became known as the ''[[Supermarine Spitfire#Name_origin|Spitfire]]'' and played a key role in the Second World War.
==References==
{{reflist}}
* Buchler, E.R. 1973. The use of echolocation by the wandering shrew, Sorex vagrans Baird. Diss. Abstr. Int. B. Sci. Eng. 33(7): 3380-3381.
* Buchler, E.R. 1976. Experimental demonstration of echolocation by the wandering shrew (Sorex vagrans). Anim. Behav. 24(4): 858-873.
* Busnel, R.-G. (Ed.). 1963. Acoustic Behaviour of Animals. Amsterdam: Elsevier Publishing Company.
* Forsman, K.A., Malmquist, M.G. 1988. Evidence for echolocation in the common shrew, Sorex araneus. J. Zool., Lond. 216 (4): 655-663. .
* Gould, E. 1962. Evidence for echolocation in shrews.Ph.D. Thesis, Tulane University.
* Gould, E., Negus, N., Novick, A. 1964. Evidence for echolocation in shrews. J. Exp. Zool. 156: 19-38.
* Hutterer, R. 1976. Deskriptive und vergleichende Verhaltensstudien an der Zwergspitzmaus, Sorex minutus L., und der Waldspitzmaus, Sorex araneus L. (Soricidae - Insectivora - Mammalia). Unpublished Ph.D. Thesis, Univ. Wien.
* Hutterer, R., Vogel., P. 1977. Abwehrlaute afrikanischer Spitzmäuse der Gattung Crocidura Wagler, 1832 und ihre systematische Bedeutung. Bonn. Zool. Beitr. 28(3/4): 218-227.
* Hutterer, R., Vogel, P., Frey, H., Genoud, M. 1979. Vocalization of the shrews Suncus etruscus and Crocidura russula during normothermia and torpor. Acta Theriol. 24(21): 267-271.
* Irwin, D.V., Baxter, R.M. 1980. Evidence against the use of echolocation by Crocidura f. flavescens (Soricidae). Säugetierk. Mitt. 28(4): 323.
* Kahmann, H., Ostermann, K. 1951. Wahrnehmen und Hervorbringen hoher Töne bei kleinen Säugetieren. Experientia 7(7): 268-269.
* Köhler, D., Wallschläger, D. 1987. Über die Lautäußerungen der Wasserspitzmaus, Neomys fodiens (Insectivora: Soricidae). Zool. Jb. Physiol. 91: 89-99.
* Sales, G., Pye, D. 1974. Ultrasonic communication by animals. London.
* Tomasi, T.E. 1979. Echolocation by the short-tailed shrew Blarina brevicauda. J. Mammalogy 60(4): 751-759.
[[Category:Shrews| ]]
[[Category:Mammals of Europe]]
[[ar:زباب]]
[[ca:Musaranya]]
[[da:Spidsmus]]
[[de:Spitzmäuse]]
[[es:Soricidae]]
[[eo:Soriko]]
[[fr:Soricidae]]
[[io:Musareno]]
[[id:Celurut]]
[[it:Soricidae]]
[[he:חדפיים]]
[[lt:Kirstukiniai]]
[[nl:Spitsmuizen]]
[[ja:トガリネズミ]]
[[no:Spissmus]]
[[nn:Spissmus]]
[[nrm:Mustchinne]]
[[pl:Ryjówkowate]]
[[pt:Musaranho]]
[[ru:Землеройковые]]
[[simple:Shrew]]
[[fi:Päästäiset]]
[[sv:Näbbmöss]]
[[tl:Soricidae]]
[[tr:Sivri faregiller]]
[[zh:鼩鼱科]]