Sorex

Key takeaways

Sorex belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sorex to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sorex from memory before moving on to harder problems.

Reference excerpt

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 (red-toothed shrews). They have 32 teeth. These animals have long, pointed snouts, small ears, which are often not visible, and scent glands located on the sides of their bodies. As their eyesight is generally poor, they rely on hearing and smell to locate their prey, mainly insects. Some species also use echolocation. Distinguishing between species without examining the dental pattern is often difficult. In some species, a female shrew and her dependent young form "caravans", in which each shrew grasps the rear of the shrew in front, when changing location.

Species Genus Sorex – most basal of the genera Kashmir pygmy shrew (S. planiceps) – India and Pakistan Tibetan shrew (S. thibetanus) – endemic to China Subgenus Otisorex – mostly North American shrews with a few species found on the Kamchatka Peninsula and islands in the Bering Sea. Chiapan shrew (S. chiapensis) Cruz's long-tailed shrew (S. cruzi) Long-tailed shrew (S. dispar) Sorex dispar blitchi Sorex dispar dispar Western pygmy shrew (S. eximius) Sorex eximius eximius Sorex eximius montanus Smoky shrew (S. fumeus) Sorex fumeus fumeus Sorex fumeus umbrosus Eastern pygmy shrew (S. hoyi) Sorex hoyi alnorum Sorex hoyi hoyi Sorex hoyi thompsoni Sorex hoyi winnemana Ibarra shrew (S. ibarrai) Large-toothed shrew (S. macrodon) Sierra shrew (S. madrensis) McCarthy's shrew (S. mccarthyi) Carmen Mountain shrew (S. milleri) Mutable shrew (S. mutabilis) Dwarf shrew (S. nanus) Mexican long-tailed shrew (S. oreopolus) Orizaba long-tailed shrew (S. orizabae) Ornate shrew (S. ornatus) Sorex ornatus juncensis S. o. lagunae S. o. ornatus S. o. relictus S. o. salarius S. o. salicornicus S. o. sinuosus S. o. willetti Inyo shrew (S. tenellus) Verapaz shrew (S. veraepacis) Ixtlan shrew (Sorex ixtlanensis) S. vagrans complex Glacier Bay water shrew (S. alaskanus) Eastern water shrew (S. albibarbis) S. a. gloveralleni S. a. labradorensis S. a. punctulatus S. a. turneri Baird's shrew (S. bairdi) S. b. bairdi S. b. permiliensis Marsh shrew (S. bendirii) S. b. albiventer S. b. bendirii S. b. palmeri Montane shrew (S. monticola) S. m. calvertensis S. m. insularis S. m. isolatus S. m. longicaudus S. m. malitiosus S. m. parvidens S. m. prevostensis S. m. setosus New Mexico shrew (S. neomexicanus) Northern montane shrew (S. obscurus) S. m. alascensis S. m. elassodon S. m. obscurus S. m. shumaginensis S. m. soperi Pacific shrew (S. pacificus) S. p. pacificus S. p. cascadensis Western water shrew (S. navigator) S. n. brooksi S. n. navigator American water shrew (S. palustris) S. p. hydrobadistes S. p. palustris Fog shrew (S. sonomae) S. s. sonomae S. s. tenelliodus Vagrant shrew (S. vagrans) S. v. halicoetes S. v. paludivagus S. v. vagrans S. cinereus group Kamchatka shrew (S. camtschaticus) Cinereous shrew (S. cinereus) S. c. acadicus S. c. cinereus S. c. hollisteri S. c. lesueurii S. c. miscix S. c. ohioensis S. c. streatori Maryland shrew (S. fontinalis) Prairie shrew (S. haydeni) Saint Lawrence Island shrew (S. jacksoni) Paramushir shrew (S. leucogaster) Southeastern shrew (S. longirostris) Mount Lyell shrew (S. lyelli) Portenko's shrew (S. portenkoi) Preble's shrew (S. preblei) Pribilof Island shrew (S. pribilofensis) Olympic shrew (S. rohweri) Barren ground shrew (S. ugyunak) Subgenus Sorex Dneper common shrew (S. averini) Lesser striped shrew (S. bedfordiae) Greater stripe-backed shrew (S. cylindricauda) Chinese highland shrew (S. excelsus) Azumi shrew (S. hosonoi) Chinese shrew (S. sinalis) Alaska tiny shrew (S. yukonicus) S. alpinus group Alpine shrew (S. alpinus) Ussuri shrew (S. mirabilis) S. araneus group Valais shrew (S. antinorii) Common shrew (S. araneus) Udine shrew (S. arunchi) Crowned shrew (S. coronatus) Siberian large-toothed shrew (S. daphaenodon) S. d. daphaenodon S. d. sanguinidens S. d. scaloni Iberian shrew (S. granarius) Caucasian shrew (S. satunini) S. arcticus group Arctic shrew (S. arcticus) S. a. arcticus S. a. laricorum Maritime shrew (S. maritimensis) S. tundrensis Tien Shan shrew (S. asper) Gansu shrew (S. cansulus) Tundra shrew (S. tundrensis) S. minutus group Buchara shrew (S. buchariensis) Kozlov's shrew (S. kozlovi) Caucasian pygmy shrew (S. volnuchini) S. v. dahli S. v. volnuchini S. caecutiens group Laxmann's shrew (S. caecutiens) Taiga shrew (S. isodon) Eurasian least shrew (S. minutissimus) Eurasian pygmy shrew (S. minutus) Flat-skulled shrew (S. roboratus) Shinto shrew (S. shinto) S. s. sadonis S. s. shikokensis S. s. shinto Long-clawed shrew (S. unguiculatus) S. gracillimus group Slender shrew (S. gracillimus) S. raddei Radde's shrew (S. raddei) S. samniticus Apennine shrew (S. samniticus) Subgenus incertae sedis Alto shrew (S. altoensis) – Mexico Arizona shrew (S. arizonae) – United States (Arizona, New Mexico) Mexico (Chihuahua) Zacatecas shrew (S. emarginatus) – Mexico Jalisco shrew (S. mediopua) – Mexico Merriam's shrew (S. merriami) – Western United States (Washington, Oregon, California, Idaho, Nevada, Utah, Arizona, New Mexico, Wyoming, Colorado) Saussure's shrew (S. saussurei) – Mexico and Guatemala S. s. godmani S. s. saussurei Salvin's shrew (S. salvini) – Mexico and Guatemala Sclater's shrew (S. sclateri) – Mexico San Cristobal shrew (S. stizodon) – Mexico Trowbridge's shrew (S. trowbridgii) – Pacific Coast United States (Washington, Oregon, California) Canada (southern British Columbia) S. t. destructioni S. t. humboldtensis S. t. mariposae S. t. montereyensis S. t. trowbridgii Chestnut-bellied shrew (S. ventralis) – Mexico Veracruz shrew (S. veraecrucis) – Mexico S. v. oaxacae S. v. veraecrucis

References

Illustrations

Worked examples

Example 1 — a first encounter with Sorex

Start with the simplest possible case. Write down what Sorex claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sorex before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sorex ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sorex

In research: Sorex appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sorex in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sorex is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal taxa named by Carl Linnaeus, Animals that use echolocation, Mammal genera, so understanding it makes those chapters shorter.
In everyday life: Look for Sorex outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Sorex in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sorex means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sorex out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sorex in simple terms?

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 (red-toothed shrews).

Why does Sorex matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sorex?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sorex.