The bicolored shrew or bicoloured white-toothed shrew (''Crocidura leucodon'') is a species of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

in the family Soricidae. It is found in eastern, central and southern Europe and in western Asia. It is a nocturnal species and feeds on insects and other small creatures. Several litters of young are born during the warmer months of the year in a nest of dry grasses in a concealed location.

Description

The bicoloured white-toothed shrew has a head and body length of and a tail length of . It weighs about . The upperside is covered in short, dense dark brown fur and the underside is white, with a sharp dividing line between the two colours. The muzzle is long and pink, the teeth are white and the ears project through the hair. The tail is sparsely covered in slightly longer hairs. Young animals are rather paler in colour. These shrews often emit a shrill twittering chatter.

Distribution and habitat

The bicoloured white-toothed shrew is found in eastern, central and southern Europe but not south western France, the Iberian Peninsula or southern Italy. It is also native to the Crimea, the Caucasus, Turkestan and Iran. In the Alps it is found at altitudes of up to . The habitat of this shrew is pastureland, cultivated fields, gardens, hedgerows, piles of rubble and rubbish heaps. It sometimes seeks shelter in buildings in winter and avoids damp locations.

Behaviour

The bicoloured white-toothed shrew is mainly nocturnal, emerging at dusk but remaining hidden in a cranny or the burrow of some other small animal by day. It is not as active as shrews in the genus ''

Sorex The genus ''Sorex'' includes many of the common shrews of Eurasia and North America, and contains at least 142 known species and subspecies. Members of this genus, known as long-tailed shrews, are the only members of the tribe Soricini of the s ...

''. It is a

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...

, and feeds on insects, spiders, and other small invertebrates and occasionally on small vertebrates. Breeding takes place between April and September and there may be two to four litters in a year. A nest of dried grasses is constructed in a concealed position, and a litter of three to nine young are born after a thirty one-day

gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

period. The young grow rapidly, suckle for about twenty six days, and become sexually mature at forty days. When danger threatens, one of a family of young shrews will grab its mother's fur near the base of her tail with its jaws, and one by one, the others will hold on to each other's tails in sequence until the whole family is linked together. The mother then rapidly leads them to safety with the young trailing along behind. If the mother is lifted in the air, the young maintain their grip and dangle in a wriggling, furry chain.

Research

The bicolored white-toothed shrew is a

natural reservoir In Infection, infectious disease ecology and epidemiology, a natural reservoir, also known as a disease reservoir or a reservoir of infection, is the population of organisms or the specific environment in which an infectious pathogen naturally li ...

species for the Borna disease virus which is the causative agent of

Borna disease Borna disease, also known as sad horse disease, is an infectious neurological syndrome of warm-blooded animals, caused by Borna disease viruses 1 and 2 (BoDV-1/2). BoDV-1/2 are neurotropic viruses of the species ''Orthobornavirus bornaense'', a ...

, a

meningoencephalitis Meningoencephalitis (; from ; ; and the medical suffix ''-itis'', "inflammation"), also known as herpes meningoencephalitis, is a medical condition that simultaneously resembles both meningitis, which is an infection or inflammation of the mening ...

of sheep, horses, and other warm-blooded animals including

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

and

cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

s, and may have links to psychiatric disorders in humans and be a hazard to man.

References

{{Taxonbar, from=Q626921 Crocidura Mammals described in 1780 Taxonomy articles created by Polbot