Common Stiletto vs Polar bear

Thereva nobilitata compared with Ursus maritimus

Key Differences

Common Stiletto is Least Concern while Polar bear is Vulnerable.

Taxonomic Classification

Rank	Common Stiletto	Polar bear
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Arthropoda (節足動物)	Chordata (脊索動物)
Class	Insecta (昆虫)	Mammalia (哺乳類)
Order	Diptera (ハエ目)	Carnivora (ネコ目)
Family	Therevidae	Ursidae (Bears)
Genus	Thereva	Ursus (Bears)
Species	Thereva nobilitata	Ursus maritimus

Evolutionary Relationship

Common Stiletto and Polar bear share a common ancestor at the Kingdom level: Animalia. (動物)

表示 Kingdom: Animalia

Conservation Status

Common Stiletto

LC — Least Concern

Polar bear

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

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

Habitat & Geographic Range

Common Stiletto

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

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 Stiletto

<em>Thereva nobilitata</em>, commonly known as the common stiletto fly, is a medium-sized fly in the family Therevidae, distributed across Europe and parts of western Asia. This species typically inhabits sandy heathlands, coastal dunes, river sandbars, open grasslands, and sparsely vegetated sandy soils where both adults and larvae can exploit loose substrates. Its geographic range extends across much of Europe from the British Isles and Scandinavia south to the Mediterranean, with records extending into parts of North Africa and western Asia. Classified as Least Concern on the IUCN Red List, <em>Thereva nobilitata</em> is among the more frequently encountered therevid flies in European sandy habitats. Adult stiletto flies are predatory, typically hunting small soft-bodied insects on the ground and in low vegetation. The larvae are also predatory, living in soil or sand where they hunt other soil-dwelling invertebrate larvae. Adults are typically grey-bodied with silvery-grey pruinosity and mottled wings, reaching a body length of approximately 10–15 mm. Biological traits such as average lifespan in years, precise body weight, and detailed dietary preferences at the prey species level remain poorly documented for this species. Adults are typically active during warm, sunny weather from late spring through summer.

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。