Jump to content

Sorex tundrensis

From WhiskerWiki

Tundra Shrew
(Sorex tundrensis)
Range
Taxonomic classification
Order:Eulipotyphla
Suborder:Erinaceota
Family:Soricidae
Subfamily:Soricinae
Tribe:Soricini
Genus:Sorex
Subgenus:Sorex (subgenus)
Species group:Sorex araneus group
Binomial details
Sorex tundrensis Merriam, 1900

Description

Adult Tundra Shrews are striking and not easily confused with other shrews. The adults are noticeably tricolored in the summer and bicolored in the winter. Subadults also have a bicolored appearance, but it may be indistinct in some individuals. Adult shown in top two photos. Subadult shown in bottom three photos.

External measurements

Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.

Part of range Reference Total length Tail length Hindfoot length Ear length Mass
rangewide Naughton (2012) 83–120 22–37 11–15 4–10 4.9–14.0


Skull

Sorex tundrensis skull characters
units in mm
Skull
Condylobasal length:17.0–18.5 (Junge & Hoffman, 1981)
Postmandibular canal:Present
Shape:Braincase is slightly rounded
Dental
Upper unicuspids:5
Unicuspid notes:U3>U4
Tines present:Yes
Tine size:Medium
Tine position:Well below upper limit of pigment on upper incisors
Shape upper incisors:Parallel or slightly diverging

Five unicuspids. Third unicuspid is larger than fourth. The inner side of the lower jaw contains a postmandibular canal. The tines on the upper incisors are small and positioned well within the upper line of pigment on the upper incisors.

  • Lateral view of the skull of a subadult Sorex tundrensis. Long scale bar represents 1 cm; short scale bar represents 1 mm.
  • Lateral view of skull of adult Sorex tundrensis. Long scale bar represents 1 cm; short scale bar represents 1 mm. Note that this is an older adult and the teeth are fairly worn.
  • Unicuspids of Sorex tundrensis. Scale bar represents 1 mm.
  • Upper incisors of Sorex tundrensis. Scale bar represents 1 mm.

Similar species

Adult Sorex tundrensis are quite distinct and not easily confused with any other species. However, subadults of Sorex tundrensis are sometimes confused with Sorex cinereus. Sorex tundrensis is quite a bit larger than S. cinereus and generally have a bicolored appearance. The tip of the tail in subadult S. tundrensis is somewhat tufted or bulbous in shape.

Sorex tundrensis tundrensis subadult
Sorex cinereus
Sorex tundrensis tundrensis upper incisors
Sorex cinereus upper incisors
Sorex tundrensis tundrensis unicuspids
Sorex cinereus unicuspids

References

Junge JA, Hoffman RS. 1981. An annotated key to the long-tailed shrews (Genus Sorex) of the United States and Canada with notes on middle American Sorex. Occasional Papers of the Museum of Natural History, The University of Kansas, Lawrence Kansas. Number 94; Pages 1-48. Link

Merriam CH. 1900. Papers from the Harriman Alaska Expedition. I. Descriptions of Twenty-six New Mammals from Alaska and British North America. Proceedings of the Washington Academy of Sciences 2, 16.

Naughton D. 2012. The natural history of Canadian mammals. Toronto (ON, CA): University of Toronto Press.

Cookies help us deliver our services. By using our services, you agree to our use of cookies.