American Bald Eagle vs Common Oak Fern

Haliaeetus leucocephalus compared with Gymnocarpium dryopteris

Key Differences

• American Bald Eagle is Not Evaluated while Common Oak Fern is Critically Endangered.

Taxonomic Classification

Rank	American Bald Eagle	Common Oak Fern
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Tracheophyta
Class	Aves (Birds)	Polypodiopsida (Polypodiopsida)
Order	Accipitriformes (Hawks & Eagles)	Polypodiales (Polypodiales)
Family	Accipitridae (Hawks & Eagles)	Cystopteridaceae
Genus	Haliaeetus (Sea Eagles)	Gymnocarpium
Species	Haliaeetus leucocephalus	Gymnocarpium dryopteris

Conservation Status

American Bald Eagle

NE — Not Evaluated

Population: ~316.7K

Trend: Increasing ↑

Common Oak Fern

CR — Critically Endangered

Physical Characteristics

Attribute	American Bald Eagle	Common Oak Fern
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 Oak Fern

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 across Europe (6 countries) and North America (Canada, United States). Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

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 Oak Fern

<em>Gymnocarpium dryopteris</em>, the common oak fern, is a delicate terrestrial fern in the family Cystopteridaceae (or Woodsiaceae, depending on classification). Despite its common name, the species is not specifically associated with oak trees; rather, it typically grows in cool, moist, shaded environments including boreal and mixed forests, rocky woodland slopes, stream banks, and shaded cliff faces. <em>Gymnocarpium dryopteris</em> spreads by rhizomes and forms low, spreading colonies with characteristic triangular, three-pinnate fronds that emerge from a slender creeping rootstock. Its geographic range spans Europe and North America, with populations in cool temperate and boreal zones. The species is currently assessed as Critically Endangered in certain regional assessments, suggesting that particular populations face severe decline, likely due to habitat loss, forest fragmentation, and altered hydrology, even if the species retains a broader global range. Biological traits such as lifespan, body size, and diet remain poorly documented at a standardized population level. <em>Gymnocarpium dryopteris</em> is a characteristic indicator of undisturbed cool woodland habitats and is valued for both its ecological role in forest understoreys and its aesthetic appeal.

Shared Countries

Both species can be found in 6 countries:

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