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Soricidae

(Family)

Overview

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A shrew or shrew mouse (family Soricidae) is a small molelike mammal classified in the order Soricomorpha. True shrews are also not to be confused with West Indies shrews, treeshrews, otter shrews, or elephant shrews, which belong to different families or orders.

Although its external appearance is generally that of a long-nosed mouse, a shrew is not a rodent, as mice are, and is in fact more closely related to moles. Shrews have sharp, spike-like teeth, not the familiar gnawing front incisor teeth of rodents.

Shrews are distributed almost worldwide: of the major tropical and temperate land masses, only New Guinea, Australia, and New Zealand do not have native shrews at all; in South America, shrews are relatively recent immigrants and are present only in the northern Andes. In terms of species diversity, the shrew family is the fourth most successful of the mammal families, being rivaled only by the muroid rodent families Muridae and Cricetidae and the bat family Vespertilionidae.

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Water shrew skeleton

All shrews are comparatively small, most no larger than a mouse. The largest species is the house shrew (Suncus murinus) of tropical Asia, which is about 15 cm long and weighs around 100 grams[citation needed]; 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 v egetation, but some specialize in climbing trees, living underground, living under snow or even hunting in water. They have small eyes, and generally poor vision, but have excellent senses of hearing and smell.[2] They are very active animals, with voracious appetites and unusually high metabolic rates. Shrews must eat 80-90 % of their own body weight in food daily.

Shrews are known for their high metabolic rates - even higher than what would be expected from such small mammals.[3]

They do not hibernate, but are capable of entering torpor. In winter, many species undergo morphological changes that drastically reduce the animal's body weight. Shrews can lose between 30% and 50% of their body weight, shrinking the size of bones, skull and internal organs.[4]

Whereas rodents have gnawing incisors 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 molars at the back of the mouth, the teeth of shrews are small and peg-like, and may be reduced in number. The dental formula of shrews is:Upper: 3.1.1-3.3, lower: 1-2.0-1.1.3

Shrews are fiercely territorial, driving off rivals, and only coming together to mate. Many species dig burrows for caching food and hiding from predators, although this is not universal.[2]

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 lactates during her pregnancy, weaning one litter as the next is born.[2] Shrews live for between 12 and 30 months.[5]

Shrews are unusual among mammals in a number of respects. Unlike most mammals, some species of shrew are venomous. Shrew venom is not conducted into the wound by fangs, but by grooves in the teeth. The venom contains various compounds, and the contents of the venom glands of the American short-tailed shrew are sufficient to kill 200 mice by intravenous injection. One chemical extracted from shrew venom may be potentially useful in the treatment of blood pressure while another compound may be useful in the treatment of some neuromuscular diseases and migraines.[6] The saliva of the Northern Short-tailed Shrew (Blarina brevicauda) contains the peptide soricidin and has accordingly been studied for use in treating ovarian cancer.[7] Also, along with the bats and toothed whales, some species of shrew use echolocation. Unlike most other mammals, shrews lack a zygomatic bone (also called the jugal), and therefore have an incomplete zygomatic arch.

Shrews hold nearly 10% of their mass in their brain, which is the highest brain to body mass ratio of all animals (including humans).[8]

Echolocation

The northern short-tailed shrew is known to echolocate

The only terrestrial mammals known to echolocate are two genera (Sorex and Blarina) of shrews and the tenrecs of Madagascar. These include the vagrant shrew (Sorex vagrans), the common or Eurasian shrew (Sorex araneus), and the northern short-tailed shrew (Blarina brevicauda). The shrews emit series of ultrasonic squeaks.[9][10] The nature of shrew sounds unlike those of bats are low amplitude, broadband, multi-harmonic and frequency modulated.[10] They contain no ?echolocation clicks? with reverberations and would seem to be used for simple, close range spatial orientation. In contrast to bats, shrews use echolocation only to investigate their habitat rather than additionally to pinpoint food.[10]

Except for large and thus strongly reflecting objects, such as a big stone or tree trunk, they will probably not be able to disentangle echo scenes, but rather derive information on habitat type from the overall call reverberations. This might be comparable to human hearing whether one calls into a beech forest or into a reverberant wine cellar.[10]

Classification

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There are 385 species of shrew in 26 genera,[11] which are grouped into three living subfamilies: Crocidurinae (white-toothed shrews), Myosoricinae (African white-toothed shrews) and Soricinae (red-toothed shrews). In addition, the family contains the extinct subfamilies Limnoecinae, Crocidosoricinae, Allosoricinae and Heterosoricinae (although Heterosoricinae is also commonly considered a separate family).

be useful in the treatment of some neuromuscular diseases and migraines.[6] The saliva of the Northern Short-tailed Shrew (Blarina brevicauda) contains the peptide soricidin and has accordingly been studied for use in treating ovarian cancer.[7] Also, along with the bats and toothed whales, some species of shrew use echolocation. Unlike most other mammals, shrews lack a zygomatic bone (also called the jugal), and therefore have an incomplete zygomatic arch.

Shrews hold nearly 10% of their mass in their brain, which is the highest brain to body mass ratio of all animals (including humans).[8]

Echolocation

The northern short-tailed shrew is known to echolocate

The only terrestrial mammals known to echolocate are two genera (Sorex and Blarina) of shrews and the tenrecs of Madagascar. These include the vagrant shrew (Sorex vagrans), the common or Eurasian shrew (Sorex araneus), and the northern short-tailed shrew (Blarina brevicauda). The shrews emit series of ultrasonic squeaks.[9][10] The nature of shrew sounds unlike those of bats are low amplitude, broadband, multi-harmonic and frequency modulated.[10] They contain no ?echolocation clicks? with reverberations and would seem to be used for simple, close range spatial orientation. In contrast to bats, shrews use echolocation only to investigate their habitat rather than additionally to pinpoint food.[10]

Except for large and thus strongly reflecting objects, such as a big stone or tree trunk, they will probably not be able to disentangle echo scenes, but rather derive information on habitat type from the overall call reverberations. This might be comparable to human hearing whether one calls into a beech forest or into a reverberant wine cellar.[10]

Classification

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There are 385 species of shrew in 26 genera,[11] which are grouped into three living subfamilies: Crocidurinae (white-toothed shrews), Myosoricinae (African white-toothed shrews) and Soricinae (red-toothed shrews). In addition, the family contains the extinct subfamilies Limnoecinae, Crocidosoricinae, Allosoricinae and Heterosoricinae (although Heterosoricinae is also commonly considered a separate family).

References

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  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. 223?300. ISBN 978-0-8018-8221-0. OCLC  62265494. http://www.bucknell.edu/msw3. 
  2. ^ a b c Barnard, Christopher J. (1984). Macdonald, D.. ed. The Encyclopedia of Mammals. New York: Facts on File. pp. 758?763. ISBN 0-87196-871-1. 
  3. ^ http://www.jstor.org/discover/10.2307/30155625?uid=3739832&uid=2&uid=4&uid=3739256&sid=55884458983
  4. ^ Churchfield, Sara (1990-01). The natural history of shrews. ISBN 978-0-8014-2595-0. http://books.google.com/books?id=z-XJ-UzdwIgC&pg=PA44&lpg=PA44&dq=seasonal+weight+changes+overwintering. 
  5. ^ Macdonald (Ed), Professor David W. (2006). The Encyclopedia of Mammals. Oxford University Press. ISBN 0-19-920608-2. 
  6. ^ Piper, Ross (2007), Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press.
  7. ^ "BioProspecting NB, Inc's novel ovarian cancer treatment found effective in animal cancer model.". 8 Apr 2009. http://www.soricimed.com/news/bioprospecting-nb-inc%E2%80%99s-novel-ovarian-cancer-treatment-found-effective-animal-cancer-model. Retrieved 23 May 2010. 
  8. ^ Brains of White Matter
  9. ^ Tomasi, T. E. (1979). "Echolocation by the Short-Tailed Shrew Blarina brevicauda". Journal of Mammalogy 60 (4): 751?9. doi:10.2307/1380190. JSTOR 1380190. 
  10. ^ a b c d Siemers, B. M.; Schauermann, G.; Turni, H.; Von Merten, S. (2009). "Why do shrews twitter? Communication or simple echo-based orientation". Biology Letters 5 (5): 593?6. doi:10.1098/rsbl.2009.0378. PMC 2781971. PMID 19535367. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2781971. 
  11. ^ Wilson, D.E.; Reeder, D.M. (2011). "Class Mammalia Linnaeus, 1758. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness". Zootaxa 3148: 56?60. http://mapress.com/zootaxa/2011/f/zt03148p060.pdf. 

Taxonomy

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The Family Soricidae is a member of the Superfamily Soricoidea. Here is the complete "parentage" of Soricidae:

The Family Soricidae is further organized into finer groupings including:

Genera

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Adeloblarina

[more]

Alloblarinella

[more]

Allosorex

[more]

Alluvisorex

[more]

Amblycoptus

[more]

Anouroneomys

[more]

Anourosorex

Anourosorex is a small genus containing four species of shrew, called "Asian mole shrews" because they resemble moles and live in Asia, mostly in China, India and Indochina. Anourrosorex is the only known extant genus of the tribe Anourosoricini of red-toothed shrews. There are four known species: [more]

Antesorex

[more]

Arctisorex

[more]

Asoriculus

[more]

Beremendia

[more]

Blarina

The genus Blarina is a group of relatively large shrews with relatively short tails found in North America. They have 32 teeth and are in the red-toothed shrew subfamily. [more]

Blarinella

Blarinella is a genus of in the Soricidae family. It contains the following species: [more]

Blarinoides

[more]

Chimarrogale

The Asiatic water shrews are the members of the genus Chimarrogale. They are in the Soricidae family. The genus contains contains the following species: [more]

Chodsigoa

[more]

Clapasorex

[more]

Congosorex

The Congo shrews are the members of the genus Congosorex. They are mammals in the Soricidae family. The genus contains the following species: [more]

Crocidura

The genus Crocidura is one of nine genus of the shrew subfamily Crocidurinae. Members of the genus are commonly called white-toothed shrews or musk shrews, although both also apply to all of the species in the subfamily. With 182 species, Crocidura contains the largest number of species of any mammal genus. [more]

Crusafontina

Cryptotis

The genus Cryptotis is a group of relatively small shrews with short ears, which are usually not visible, and short tails, commonly called small-eared shrews. They have 30 teeth and are members of the red-toothed shrew subfamily. Since 1992, Neal Woodman (in cooperation with Robert Timm) at the United States National Museum has been in the process of revising the genus. To date, this has resulted in an increase in the number of species from 12 to 30. [more]

Deinsdorfia

[more]

Dinosorex

[more]

Diplomesodon

The Piebald Shrew (Diplomesodon pulchellum) is a shrew found in the Turan Lowland east of the Caspian Sea in Turkmenistan and Uzbekistan. It grows to 2?2 inches in length, and usually hunts for insects and lizards at night. It is the only member of the genus Diplomesodon. [more]

Domnina

[more]

Episoriculus

A Genus in the Kingdom Animalia.[1] [more]

Feroculus

Kelaart's Long-clawed Shrew (Feroculus feroculus) is a species of mammal in the family Soricidae. It is monotypic within the genus Feroculus.[] It is endemic to Sri Lanka and southern India. Its natural habitats are subtropical or tropical dry forests, subtropical or tropical dry lowland grassland, and swamps. It is threatened by habitat loss. [more]

Florinia

Hesperosorex

Heterosorex

Limnoecus

Megasorex

The Mexican Shrew (Megasorex gigas) is a species of mammal from the subfamily Soricinae in the family Soricidae. It is monotypic within the genus Megasorex.[] It is endemic to Mexico. [more]

Miosorex

Myosorex

Myosorex is a genus in the Soricidae (shrew) family. The genus contains the following species: [more]

Nectogale

The Elegant Water Shrew (Nectogale elegans) is a species of mammal in the subfamily Soricinae of the family Soricidae. It is monotypic within the genus Nectogale.[] It is found in Sikkim and China. [more]

Neomys

The genus Neomys is a group of three Eurasian water shrews from the subfamily Soricinae of the family Soricidae. These shrews are found in most of Europe, and parts of Northern Asia as well as Turkey and Iran. Its member species are: [more]

Neomysorex

Nesiotites

[more]

Notiosorex

Notiosorex is a genus of shrew from the subfamily Soricinae. [more]

Oligosorex

[more]

Pachyura

A Genus in the Kingdom Animalia.[2] [more]

Paenelimnoecus

Paenesorex

Paracrocidura

The large-headed shrews are the members of the genus Paracrocidura. The are in the Soricidae family. The genus contains the following species: [more]

Paracryptotis

Paradomnina

Paranourosorex

Parasorex

Petenyia

Planisorex

Praesorex

A Genus in the Kingdom Animalia.[3] [more]

Pseudotrimylus

Ruwenzorisorex

The Ruwenzori Shrew (Ruwenzorisorex suncoides) is a species of in the Soricidae family. It is monotypic within the genus Ruwenzorisorex. It is found in Burundi, Democratic Republic of the Congo, Rwanda, and Uganda. Its natural habitat is subtropical or tropical moist montanes. [more]

Scutisorex

The Hero Shrew (Scutisorex somereni), also known as the Armored Shrew, is a large shrew native to Africa, which has a highly unusual spinal column. Its corrugated interlocking vertebrae are quite different from those found in other shrews, or in fact, in any other type of mammal. The modifications in the shrew's backbone are remarkable. Its 11 lumbar vertebrae sport interlocking spines on their sides and lower surfaces. These spines mesh with the projections on the vertebrae behind and in front, creating an incredibly strong, yet flexible structure. The spine is so elaborate that it accounts of 4% of the shrew's body weight. In other small mammals the spine only accounts for 0.5-1.6% of the overall mass. The modifications to this small animal's body haven't stopped at the spine. The ribs are much thicker than those of similarly sized mammals and the spinal muscles have undergone some radical changes. The transverse muscles are reduced, while the muscles that extend and flex the spine are well developed, which results in the shrew's peculiar gait with the spine flexing in a snake-like manner. The Hero Shrew feeds on insects, snails, worms and small lizards. [more]

Solisorex

The Pearson's Long-clawed Shrew (Solisorex pearsoni) is a species of in the Soricidae family. It is monotypic within the genus Solisorex. It is endemic to Sri Lanka. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry lowland grassland. It is threatened by habitat loss. [more]

Sorex

The genus Sorex includes many of the common shrews of Eurasia and North America. Members of this genus, known as long-tailed shrews, are the only members of the tribe Soricini of the subfamily Soricinae (red-toothed shrews). They have 32 teeth. [more]

Soricella

[more]

Soriculus

Soriculus is a genus of in the Soricidae family. It contains the following species: [more]

Soroplex

[more]

Sulimskia

Suncus

Suncus is a genus of shrews in the family Soricidae. [more]

Surdisorex

Surdisorex is a genus of in the Soricidae family. They are one of three basic types of African Shrews, which, in turn, are one of the three basic families of shrews. They are called African Mole Shrews because of their remarkable similarity to moles, to which they are not closely related. There are only two species, both found only in Kenya: [more]

Sylvisorex

The forest shrews are the members of the genus Sylvisorex. They are in the Soricidae family and all are found only in Africa. The genus name comes from the Latin world "silva" which means "Forest" and sorex, which means "shrew-mouse" and which is the main genus of shrews, and the basis for their order, Soricomorpha. The meaning of the genus reflects the nature of these shrews, which prefer forest habitats, and which is incorporated in all of their names but one. All shrews are carnivorous, and eat continually to fuel their extremely quick metabolisms. [more]

Tregosorex

Trimylus

[more]

Wilsonosorex

More info about the Genus Wilsonosorex may be found here.

References

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  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. 223?300. ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3. 
  2. ^ a b c Barnard, Christopher J. (1984). Macdonald, D.. ed. The Encyclopedia of Mammals. New York: Facts on File. pp. 758?763. ISBN 0-87196-871-1. 
  3. ^ http://www.jstor.org/discover/10.2307/30155625?uid=3739832&uid=2&uid=4&uid=3739256&sid=55884458983
  4. ^ Churchfield, Sara (1990-01). The natural history of shrews. ISBN 978-0-8014-2595-0. http://books.google.com/books?id=z-XJ-UzdwIgC&pg=PA44&lpg=PA44&dq=seasonal+weight+changes+overwintering. 
  5. ^ Macdonald (Ed), Professor David W. (2006). The Encyclopedia of Mammals. Oxford University Press. ISBN 0-19- 920608-2. 
  6. ^ Piper, Ross (2007), Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press.
  7. ^ "BioProspecting NB, Inc's novel ovarian cancer treatment found effective in animal cancer model.". 8 Apr 2009. http://www.soricimed.com/news/bioprospecting-nb-inc%E2%80%99s-novel-ovarian-cancer-treatment-found-effective-animal-cancer-model. Retrieved 23 May 2010. 
  8. ^ Brains of White Matter
  9. ^ Tomasi, T. E. (1979). "Echolocation by the Short-Tailed Shrew Blarina brevicauda". Journal of Mammalogy 60 (4): 751?9. doi:10.2307/1380190. JSTOR 1380190. 
  10. ^ a b c d Siemers, B. M.; Schauermann, G.; Turni, H.; Von Merten, S. (2009). "Why do shrews twitter? Communication or simple echo-based orientation". Biology Letters 5 (5): 593?6. doi:10.1098/rsbl.2009.0378. PMC 2781971. PMID 19535367. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2781971. 
  11. ^ Wilson, D.E.; Reeder, D.M. (2011). "Class Mammalia Linnaeus, 1758. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness". Zootaxa 3148: 56?60. http://mapress.com/zootaxa/2011/f/zt03148p060.pdf. 

Footnotes

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  1. http://www.ubio.org/browser/details.php?namebankID=112711
  2. http://www.ubio.org/browser/details.php?namebankID=113230
  3. http://www.ubio.org/browser/details.php?namebankID=113356

Further Reading

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External links

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Sources

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Last Revised: August 24, 2012
2012/08/24 13:43:14