Pribilof Island shrew | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Eulipotyphla |
Family: | Soricidae |
Genus: | Sorex |
Species: | S. hydrodromus |
Binomial name | |
Sorex hydrodromus Merriam, 1895 | |
Pribilof Island shrew range | |
Sorex hydrodromus range | |
Synonyms | |
Sorex pribilofensis |
The Pribilof Island shrew (Sorex hydrodromus or Sorex pribilofensis) is a small, short tailed species of mammal in the family Soricidae (shrews). [3] It is endemic to and found only on Alaska's Pribilof Islands. [3] [4] Due to its distinct tricoloured coat, it was originally thought to be related to the Arctic shrew (Sorex arcticus), but it is in fact much closer to the Cinereus shrew (Sorex cinereus) in its geographical distribution and morphological traits. [5] Not much is known about the population size, breeding habits, ecology, and the general biology of the shrew. [3]
General description
In the summer months, the shrew's pelage is tricoloured with a brownish back, pale-brownish sides, and a grey underside. In the winter, the shrew's pelage is bicoloured with a brownish back and a grey underside. [3] [5] It has a short tail. The length of the shrew ranges from 9.3 to 9.7 cm (3.63 to 3.75 in); its tail length ranging from 3.3 to 4.3 cm (1.25 to 1.63 in); its hind foot length ranging from 1.2 to 1.3 cm (0.5 in). [5] Its weight typically ranges from 4 to 5 grams (0.14 to 0.18 oz). [3] It has a long, slender, pointed snout and has five-clawed toes on both fore- and hind feet. [5]
Skull anatomy
The skull is broad, with a dental pattern similar to the Cinereus shrew (S. cinereus), the Barren ground shrew (S. ugyunak), and the Saint Lawrence Island shrew (S. jacksoni). The first and second unicuspid are similar in size; the third unicuspid is slightly larger or similar in size than the fourth. The fifth unicuspid is very small. It has large incisors compared to shrew species such as Alaska tiny shrew (S. yukonicus). [3] The anterior and posterior tooth cusps (incisors, unicuspids, premolars, molars) have a chestnut-coloured tip distinctive of the 33 species of North American shrews. [5] [6]
The Pribilof Island shrew is found exclusively on the Saint Paul Island of the Pribilof Islands, just west of Alaska, in the Bering Sea. [3] [5] It is endemic to the Pribilof Islands, however there is some confusion of its type locality. The shrew has been found in marshy habitats dominated by Leymus arenarius (lyme grass). [3] [7]
Shrews are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to different families or orders.
The red-toothed shrews of the subfamily Soricinae are one of three living subfamilies of shrews, along with Crocidurinae and Myosoricinae. In addition, the family contains the extinct subfamilies Limnoecinae, Crocidosoricinae, Allosoricinae and Heterosoricinae. These species are typically found in North America, northern South America, Europe and northern Asia. The enamel of the tips of their teeth is reddish due to iron pigment. The iron deposits serve to harden the enamel and are concentrated in those parts of the teeth most subject to wear. Members of the genera Chimarrogale, Nectogale, Neomys (Nectogalini) and some members of Sorex (Soricini) are known as water shrews, due to having a semi-aquatic lifestyle.
The cinereus shrew or masked shrew is a small shrew found in Alaska, Canada, and the northern United States. This is the most widely distributed shrew in North America, where it is also known as the common shrew.
The American pygmy shrew is a small shrew found in Northern Alaska, Canada, and the northern United States, south through the Appalachian Mountains. It was first discovered in 1831 by naturalist William Cane in Georgian Bay, Parry Sound.
The marsh shrew, also known as the Pacific water shrew, Bendire's water shrew, Bendire's shrew and Jesus shrew is the largest North American member of the genus Sorex. Primarily covered in dark-brown fur, it is found near aquatic habitats along the Pacific coast from southern British Columbia to northern California. With air trapped in its fur for buoyancy, marsh shrews can run for three to five seconds on top of the water. It measures about 16 cm (6.3 in) in length, including a 7-centimetre (2.8 in)-long tail, and weighs an average of 14.5–16 g (0.51–0.56 oz). The marsh shrew's diet consists mainly of invertebrates, which it hunts on land and in the water. They are rare; their populations are thought to be in decline, and they are considered endangered in parts of their range.
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 subfamily Soricinae. They have 32 teeth.
The barren ground shrew is a small shrew found in northern Canada west of Hudson Bay and in Alaska. At one time, this species was considered to be a subspecies of the similar cinereus shrew. It is similar in appearance and thought to be closely related to the Saint Lawrence Island shrew and Pribilof Island shrew.
The Gansu shrew is a red-toothed shrew found only in a small part of Gansu province and other adjacent areas of China. With its very limited range, it is sensitive to habitat loss and is listed as a "vulnerable species" in the Chinese Red List, while the IUCN lists it as being "data deficient"
Laxmann's shrew, or the masked shrew, is a species of shrew. Its range extends from northern Scandinavia and the Baltic to the Sea of Japan, including Hokkaidō, Sakhalin, and the Korean Peninsula. It favours mountain forests but is sometimes found in tundra and moorland, and also in lowland areas as well. It avoids cultivated land.
The montane shrew is a species of mammal in the family Soricidae commonly known as the dusky shrew. Monticolus is derived from the Latin root word mons meaning mountain. It is found in Alaska, western Canada, the western United States in Washington, Idaho, Montana, Utah, Colorado, New Mexico, Arizona, Oregon, Nevada, and California, as well as in Mexico.
The dwarf shrew is a species of mammal in the family Soricidae endemic to Arizona, Colorado, Montana, Nebraska, New Mexico, South Dakota, Utah, and Wyoming in the United States. The type locality is Estes Park, Colorado, USA.
The Pacific shrew is a species of mammal in the family Soricidae. It is endemic to western Oregon in the United States. The Pacific Shrew is native to western Oregon, more specifically from the Siltcoos lake to the coast going from the border line of Douglas and Lane counties continuing south to the northern parts of California. The first documented Pacific shrew to be caught was found at the mouth of the Umpqua River in 1858. They are normally found in damp areas along creeks in forests and sometimes near collapsed trees. Their refuge is of the utmost importance and they are seldom found far from it. This includes collapsed trees or dense vegetation. They use the flora to build a nest, gathering small plants such as grass, moss, lichen, or leaves into a pile and pushing themselves into the middle.
Preble's shrew is a small shrew distributed across the Great Basin of the United States and southern British Columbia in Canada.
The Shinto shrew is a species of shrew of the genus Sorex that lives only on the islands of Japan. It is a mole-like mammal with a pointed snout, very small ears, and a relatively long tail. Like most shrews, it is tiny, has poor eyesight, and a very good sense of hearing and smell which it uses to locate its prey, mainly insects.
The fog shrew is a species of mammal in the family Soricidae. It is endemic to northern California and Oregon in the United States.
The Inyo shrew is a species of shrew found in the western United States. It is light gray and white in color, with a narrow skull and small body size, very similar in appearance to the related dwarf shrew, but paler and not as large. It can be found in many different habitats, from rocky, mountainous regions to wetlands and riparian areas. Not much is known about its behavioral and reproductive habits. While barely studied, their population is believed to be stable and not under any threat.
Trowbridge's shrew is a species of mammal in the family Soricidae. It is found in southern British Columbia in Canada and in Washington, Oregon, and California in the United States.
The southeastern shrew is a species of mammal in the family Soricidae. It is found in the southeastern United States.
The New Mexico shrew is a species of mammal in the family Soricidae. It is found only in New Mexico in the Capitan and Sandia-Manzano Mountains.
The long-tailed shrew or rock shrew is a small shrew found in Atlantic Canada and the Northeastern United States.