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 (فطر)	Animalia (حيوانات)
Phylum	Basidiomycota (دعاميات)	Chordata (حبليات)
Class	Agaricomycetes (غاريقونانية)	Mammalia (ثدييات)
Order	Agaricales (غاريقونيات)	Carnivora (لواحم)
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

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.

Shared Countries

Both species can be found in 1 countries:

🇳🇴 Norway