Common Nut Truffle vs Polar bear

Hymenogaster vulgaris compared with Ursus maritimus

Key Differences

• Common Nut Truffle is Data Deficient while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Common Nut Truffle	Polar bear
Kingdom	Fungi (菌界)	Animalia (動物)
Phylum	Basidiomycota (担子菌門)	Chordata (脊索動物)
Class	Agaricomycetes (真正担子菌綱)	Mammalia (哺乳類)
Order	Agaricales (ハラタケ目)	Carnivora (ネコ目)
Family	Hymenogastraceae	Ursidae (Bears)
Genus	Hymenogaster	Ursus (Bears)
Species	Hymenogaster vulgaris	Ursus maritimus

Conservation Status

Common Nut Truffle

DD — Data Deficient

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common Nut Truffle	Polar bear
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Common Nut Truffle

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Distributed across Denmark, Norway, Portugal, Sweden, and 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.

Common Nut Truffle

<em>Hymenogaster vulgaris</em>, the common nut truffle, is a hypogeous (below-ground) fungus in the family Hymenogastraceae, order Agaricales. This sequestrate species produces enclosed, truffle-like fruiting bodies that mature underground and rely primarily on small mammals and invertebrates for spore dispersal, as the sporocarps never open to release spores aerially. <em>Hymenogaster vulgaris</em> typically forms ectomycorrhizal associations with hardwood tree species, particularly oaks and beeches, in temperate European forests. Its geographic range includes Denmark, Norway, Portugal, Sweden, and the United States, reflecting a somewhat scattered distribution across temperate zones. The species is currently assessed as Data Deficient by the IUCN, indicating that insufficient information exists to evaluate its conservation status, likely because hypogeous fungi are difficult to survey and their population trends are poorly known. Biological traits such as lifespan, body size, and diet remain poorly documented for this species. As an ectomycorrhizal fungus, <em>Hymenogaster vulgaris</em> plays a critical role in facilitating nutrient uptake in host trees and supporting forest health across its temperate range.

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。

Shared Countries

Both species can be found in 1 countries:

🇳🇴 Norway