Canadian beaver vs Polar bear

Castor canadensis compared with Ursus maritimus

Key Differences

Canadian beaver is Not Evaluated while Polar bear is Vulnerable.
Canadian beaver is herbivore while Polar bear is carnivore.
Polar bear is 18.0x heavier than Canadian beaver.
Polar bear lives longer (25 years vs 15 years).

Taxonomic Classification

Rank	Canadian beaver	Polar bear
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum same	Chordata (脊索動物)	Chordata (脊索動物)
Class same	Mammalia (哺乳類)	Mammalia (哺乳類)
Order	Rodentia (ネズミ目)	Carnivora (ネコ目)
Family	Castoridae (Beavers)	Ursidae (Bears)
Genus	Castor (Beavers)	Ursus (Bears)
Species	Castor canadensis	Ursus maritimus

Evolutionary Relationship

Canadian beaver and Polar bear share a common ancestor at the Class level: Mammalia. (哺乳類)

表示 Class: Mammalia

Conservation Status

Canadian beaver

NE — Not Evaluated

Population: ~15.0M

Trend: Stable →

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Canadian beaver	Polar bear
Diet	Herbivore	Carnivore
Average Lifespan	15 years	25 years
Average Length	1.0 m	2.4 m
Average Weight	25.0 kg	450.0 kg

Habitat & Geographic Range

Canadian beaver

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Widely distributed across Europe (15 countries), North America (United States), and South America (Argentina, Chile).

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.

Canadian beaver

北米最大の齧歯類であるカナダビーバーは体重32kgにも達し、カナダ・米国北部の河川、湖沼、湿地に生息する優れた生態系エンジニアです。木を倒して数百メートルに及ぶダムを造ることで池を形成し、数百種の生息環境を提供します。その巣穴や運河は流域全体を変化させます。かつては毛皮のために絶滅寸前まで狩られましたが、個体数は大きく回復しています。

Polar bear

地球上で最大の陸上肉食動物であるホッキョクグマは700kgを超えることがあり、カナダからロシアまでの北極海氷域全体に分布する。ワモンアザラシとヒゲアザラシを狩るために海氷に依存する高度に特化した海洋哺乳類である。広大な距離を泳ぐことができる優れた泳者でもある。脆弱種に指定されており、気候変動による急激な北極海氷の消失で個体群が深刻な圧力を受けている。