American Bald Eagle vs Common Pill Woodlouse

Haliaeetus leucocephalus compared with Armadillidium vulgare

Key Differences

• American Bald Eagle is Not Evaluated while Common Pill Woodlouse is Near Threatened.

Taxonomic Classification

Rank	American Bald Eagle	Common Pill Woodlouse
Kingdom same	Animalia (hayvan)	Animalia (hayvan)
Phylum	Chordata (Kordalılar)	Arthropoda (Eklem bacaklılar)
Class	Aves (kuş)	Malacostraca (Malakostraka)
Order	Accipitriformes (Hawks & Eagles)	Isopoda (Isopoda)
Family	Accipitridae (Hawks & Eagles)	Armadillidiidae
Genus	Haliaeetus (Sea Eagles)	Armadillidium
Species	Haliaeetus leucocephalus	Armadillidium vulgare

Evolutionary Relationship

American Bald Eagle and Common Pill Woodlouse share a common ancestor at the Kingdom level: Animalia. (hayvan)

Conservation Status

American Bald Eagle

NE — Not Evaluated

Population: ~316.7K

Trend: Increasing ↑

Common Pill Woodlouse

NT — Near Threatened

Physical Characteristics

Attribute	American Bald Eagle	Common Pill Woodlouse
Diet	Carnivore	—
Average Lifespan	28 years	—
Average Length	90 cm	—
Average Weight	5.0 kg	—

Habitat & Geographic Range

American Bald Eagle

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 Pill Woodlouse

Habitat

Typically found in marine, freshwater, and terrestrial environments.

Range

Widely distributed across Africa (South Africa), Asia (Japan), Europe (6 countries), and North America (United States). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

American Bald Eagle

The national bird of the United States and a symbol of American conservation success, bald eagles have a wingspan of up to 2.4 meters and inhabit forests and wetlands near open water across North America. Powerful aerial predators and scavengers, they specialize in fish but also take waterfowl and carrion. Nearly extinct by the 1960s due to DDT poisoning and hunting, the bald eagle recovered dramatically following pesticide bans and the Endangered Species Act.

Common Pill Woodlouse

<em>Armadillidium vulgare</em>, the common pill woodlouse, is a terrestrial isopod crustacean in the family Armadillidiidae, widely recognised for its ability to roll into a tight sphere when disturbed, a defensive behaviour that gives it the common name "pill bug" or "roly-poly." Unlike most crustaceans, it is fully adapted to life on land, breathing through modified gill-like structures that must remain moist. The species inhabits a broad range of environments, typically occurring under rocks, leaf litter, decaying wood, and in gardens and agricultural land, where it feeds on decomposing organic matter, playing an important role in nutrient cycling. <em>Armadillidium vulgare</em> is distributed across Europe, parts of Asia including Japan, South Africa, and North America including the United States, reflecting its success as a cosmopolitan species often transported inadvertently by human activity. It is assessed as Near Threatened on the IUCN Red List. Biological traits such as average lifespan, precise body dimensions, and detailed dietary composition across its range remain poorly documented in the scientific literature. Females brood their young in a marsupium, and the species is capable of parthenogenesis under certain conditions, contributing to reproductive flexibility.

Shared Countries

Both species can be found in 5 countries:

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