The Eurasian least shrew (''Sorex minutissimus''), also called the lesser pygmy shrew, is the second-smallest mammal by mass after the Etruscan shrew.

Appearance

The Eurasian least shrew weighs only and has a body less than long, with a tail. It has a brown back and a light grey underside, with a fairly clear boundary in between. The color of the back varies seasonally from chocolate brown in summer to light brown in winter. The same bicolor pattern extends to the tail, which has a dark brown tuft of hair at the end. The feet are the same color as the belly, with brown heels.

Distribution

The Eurasian least shrew inhabits the northern

taiga Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces ...

region, and is found throughout

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part o ...

, in northern

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

(

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bo ...

, northern Sweden and parts of

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

) and on the islands of

Sakhalin Sakhalin ( rus, Сахали́н, r=Sakhalín, p=səxɐˈlʲin; ja, 樺太 ''Karafuto''; zh, c=, p=Kùyèdǎo, s=库页岛, t=庫頁島; Manchu: ᠰᠠᡥᠠᠯᡳᠶᠠᠨ, ''Sahaliyan''; Orok: Бугата на̄, ''Bugata nā''; Nivkh: ...

and Hokkaidō. It can be found in diverse habitats, including both

conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ex ...

ous and

deciduous forest In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, af ...

s, open fields, and the edges of

bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...

s. The population density appears to be fairly low throughout, though its prevalence may be underestimated in surveys since its small size lets it escape many commonly used traps.

Behavior

Due to its small size and reclusive habits, the Eurasian least shrew can be difficult to spot. Like shrews in general, the Eurasian least shrew mainly eats

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

s, but will also dine on

carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...

or any other source of protein it finds. In winter, it may occasionally seek food indoors. Because of its small size for a mammal, the Eurasian least shrew has an extremely high

metabolic rate Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cel ...

and must eat frequently to avoid starvation; in captivity it has been reported to eat 120 meals a day, consuming three to four times its own weight each day. The Eurasian least shrew is active around the clock, with occasional sleep periods of 10–50 minutes each. The Eurasian least shrew can

swim Swim or SWIM may refer to: Movement and sport * Swim, a fad dance * Aquatic locomotion, the act of biologically propelled motion through a liquid medium * Human swimming, the useful or recreational activity of movement through water * Swimming ( ...

well, and in captivity even seems to enjoy playing in water. Its small size also makes the Eurasian least shrew a phenomenal climber: it has been observed climbing up even the smooth inside corner of a glass terrarium. Its eyesight is poor, but it has very good hearing. While the Eurasian least shrew frequently emits sounds, much of its communication is in

frequencies Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from '' angular frequency''. Frequency is measured in hertz (Hz) which is e ...

beyond the limits of human hearing.

Breeding

The female Eurasian least shrew has one or two litters a year, each typically consisting of 3–6 offspring. Little is known about the typical lifetime of the Eurasian least shrew in the wild, but in captivity some have managed to reach an age of over 2.5 years.

Identification

The Eurasian least shrew may be mistaken for the slightly larger Eurasian pygmy shrew (''S. minutus''), which is commonly found in the same areas. Besides the size difference, the two species may be distinguished by the tail and feet of the least shrew being noticeably shorter in proportion to its body.

References

* Siivonen, Lauri (ed.) (1972). ''Suomen Nisäkkäät''. Otava, Keuruu. . * Jensen, Birger (1993). ''Suomen ja Pohjolan Nisäkkäät''. (Original title: ''Nordens Pattedyr''.) WSOY, Porvoo. . * Bjärvall, Anders; Ullström, Staffan (1995). ''Euroopan nisäkkäät''. (Original title: ''Däggdjur. Alla Europas arter''.) Tammi, Helsinki. . * Siivonen, Lauri; Sulkava, Seppo (1999). ''Pohjolan nisäkkäät (Mammals of Northern Europe)''. Otava, Keuruu. . * Savela, Markku. ''Lepidoptera and some other life forms''
"''Sorex minutissimus''"
URL accessed 9 March 2006. {{Authority control Sorex Mammals of Asia Mammals of Europe Least concern biota of Asia Least concern biota of Europe Mammals described in 1780 Taxa named by Eberhard August Wilhelm von Zimmermann