Eurasian Least Shrew
Encyclopedia
The Eurasian Least Shrew (Sorex minutissimus), also called the Lesser Pygmy Shrew, is the second-smallest mammal in the world after the Etruscan Shrew.
s and has a body less than 4 cm long, with a 2.5 cm tail. This shrew
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.
region, and is found throughout Siberia
, in northern Europe
(Finland
, northern Sweden
and parts of Norway
) and on the islands of Sakhalin
and Hokkaidō
. It can be found in diverse habitats, including both coniferous and deciduous forests, open fields, and the edges of bog
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.
s, but will also dine on carrion
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 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
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 beyond the limits of human hearing.
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.
(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.
Appearance
The Eurasian Least Shrew weighs only 1.2–4 gramGram
The gram is a metric system unit of mass....
s and has a body less than 4 cm long, with a 2.5 cm tail. This shrew
Shrew
A shrew or shrew mouse 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...
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 taigaTaiga
Taiga , also known as the boreal forest, is a biome characterized by coniferous forests.Taiga is the world's largest terrestrial biome. In North America it covers most of inland Canada and Alaska as well as parts of the extreme northern continental United States and is known as the Northwoods...
region, and is found throughout Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
, in northern Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
(Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...
, northern Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
and parts of Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
) and on the islands of Sakhalin
Sakhalin
Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...
and Hokkaidō
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...
. It can be found in diverse habitats, including both coniferous and deciduous forests, open fields, and the edges of bog
Bog
A bog, quagmire or mire is a wetland that accumulates acidic peat, a deposit of dead plant material—often mosses or, in Arctic climates, lichens....
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 insectInsect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, but will also dine on carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
or any other source of protein it finds. In winter, it may occasionally seek food indoors. Because of its small size for a mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
, the Eurasian Least Shrew has an extremely high metabolic rate 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
Aquatic locomotion
Swimming is biologically propelled motion through a liquid medium. Swimming has evolved a number of times in a range of organisms ranging from arthropods to fish to molluscs.-Evolution of swimming:...
well, and in captivity even seems to enjoy playing in water. Its small size also makes the Eurasian Least Shrew a phenomenal climber
Climbing
Climbing is the activity of using one's hands and feet to ascend a steep object. It is done both for recreation and professionally, as part of activities such as maintenance of a structure, or military operations.Climbing activities include:* Bouldering: Ascending boulders or small...
: 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 beyond the limits of human hearing.
Breeding
The female Eurasian Least Shrew has one or two littersLitter (animal)
A litter is the offspring at one birth of animals from the same mother and usually from one set of parents. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from...
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 ShrewEurasian pygmy shrew
The Eurasian Pygmy Shrew , often known simply as the Pygmy Shrew, is a widespread shrew of northern Eurasia. It is the only shrew native to Ireland....
(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.