白头海雕 vs common pygmy woodlouse

Haliaeetus leucocephalus compared with Trichoniscus pusillus

Key Differences

• 白头海雕 is Not Evaluated while common pygmy woodlouse is Least Concern.

Taxonomic Classification

Rank	白头海雕	common pygmy woodlouse
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum	Chordata (脊索动物门)	Arthropoda (节肢动物门)
Class	Aves (鳥綱)	Malacostraca (软甲纲)
Order	Accipitriformes (鷹形目)	Isopoda (等足目)
Family	Accipitridae (Hawks & Eagles)	Trichoniscidae
Genus	Haliaeetus (Sea Eagles)	Trichoniscus
Species	Haliaeetus leucocephalus	Trichoniscus pusillus

Evolutionary Relationship

白头海雕 and common pygmy woodlouse share a common ancestor at the Kingdom level: Animalia. (动物界)

Conservation Status

白头海雕

NE — Not Evaluated

Population: ~316.7K

Trend: Increasing ↑

common pygmy woodlouse

LC — Least Concern

Physical Characteristics

Attribute	白头海雕	common pygmy woodlouse
Diet	Carnivore	—
Average Lifespan	28 years	—
Average Length	90 cm	—
Average Weight	5.0 kg	—

Habitat & Geographic Range

白头海雕

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and flooded grasslands and savannas, among 10 distinct biome types spanning the Neotropic and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Europe (8 countries), North America (United States), and South America (Ecuador).

common pygmy woodlouse

Habitat

Typically found in marine, freshwater, and terrestrial environments.

Range

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

白头海雕

白头海雕是美国国鸟，也是美国生态保护史上的成功案例，曾因滴滴涕（DDT）的广泛使用而濒临灭绝，经保护措施的实施后种群数量已显著恢复。该物种在IUCN红色名录中被评估为无危（LC），以白色头颈和尾羽与深棕色体羽形成的鲜明对比为主要识别特征。它们主要以鱼类为食，也会捕食哺乳动物和腐肉。

common pygmy woodlouse

The Common Pygmy Woodlouse, <em>Trichoniscus pusillus</em>, is a small terrestrial isopod crustacean in the family Trichoniscidae, widely distributed across Europe and introduced to North America, with records from Denmark, Norway, Portugal, Sweden, and the United States. It is one of the most abundant and widespread woodlice in temperate regions, typically found in moist, dark microhabitats including under stones, logs, leaf litter, bark, and in soil crevices in gardens, woodlands, and grasslands. <em>Trichoniscus pusillus</em> is a very small species, measuring only a few millimeters in length, with a reddish-brown to pale pink coloration and a smooth, slightly convex body. Unlike many larger woodlice, it does not roll into a ball when disturbed. The species plays an important role in decomposition and nutrient cycling, fragmenting decaying plant material and facilitating microbial breakdown. It is parthenogenetic in many parts of its range, with all-female populations reproducing without males. The species is assessed as Least Concern on the IUCN Red List given its abundance and widespread distribution. Biological traits such as average lifespan, body size, and specific dietary preferences remain poorly documented for this species.

Shared Countries

Both species can be found in 4 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States