cinereus shrew vs Polar bear

Sorex cinereus compared with Ursus maritimus

Key Differences

• cinereus shrew is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank	cinereus shrew	Polar bear
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Mammalia (Mammals)	Mammalia (Mammals)
Order	Soricomorpha (Soricomorpha)	Carnivora (Carnivorans)
Family	Soricidae	Ursidae (Bears)
Genus	Sorex	Ursus (Bears)
Species	Sorex cinereus	Ursus maritimus

Evolutionary Relationship

cinereus shrew and Polar bear share a common ancestor at the Class level: Mammalia. (Mammals)

Conservation Status

cinereus shrew

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	cinereus shrew	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

cinereus shrew

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in United States.

Polar bear

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

cinereus shrew

The cinereus shrew (Sorex cinereus), also known as the masked shrew, is a small insectivorous mammal in the family Soricidae, native to North America. It has one of the widest distributions of any North American shrew, ranging from Alaska and Canada south through the northern United States, with isolated populations in the Appalachian Mountains and Rocky Mountains. It inhabits a broad range of habitats including moist forest, meadows, bogs, marshes, and brushy areas, where it hunts continuously for insects, earthworms, small vertebrates, fungi, and carrion to fuel its extremely rapid metabolism. Like all shrews, the cinereus shrew has a very high metabolic rate and must consume almost its own body weight in food daily. It is tiny—typically 3–5 grams—with dense gray-brown fur. The species is classified as Least Concern by the IUCN, with abundant and widespread populations across the boreal and northern temperate zones. It is a major component of small mammal communities in northern forests and plays an important role in food webs as prey for owls, hawks, and weasels. The species reproduces rapidly, with multiple litters per year, helping sustain populations despite high predation pressure. It is entirely North American and does not occur in Europe.

Polar bear

The largest land carnivore on Earth, polar bears can exceed 700 kg and are found across Arctic sea ice from Canada to Russia. Highly specialized marine mammals that rely on sea ice to hunt ringed and bearded seals. Excellent swimmers capable of covering vast distances in open water. Listed as Vulnerable, with populations under severe pressure from rapid Arctic sea ice loss due to climate change.