Common Seal vs Red-breasted Merganser

Phoca vitulina compared with Mergus serrator

Key Differences

• Common Seal is Near Threatened while Red-breasted Merganser is Least Concern.

Taxonomic Classification

Rank	Common Seal	Red-breasted Merganser
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Aves (Birds)
Order	Pinnipedia (Seals & Sea Lions)	Anseriformes (Anseriformes)
Family	Phocidae (True Seals)	Anatidae
Genus	Phoca (Harbor Seals)	Mergus
Species	Phoca vitulina	Mergus serrator

Evolutionary Relationship

Common Seal and Red-breasted Merganser share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Common Seal

NT — Near Threatened

Population: ~500.0K

Trend: Stable →

Red-breasted Merganser

LC — Least Concern

Physical Characteristics

Attribute	Common Seal	Red-breasted Merganser
Diet	Carnivore	—
Average Lifespan	30 years	—
Average Length	1.7 m	—
Average Weight	80.0 kg	—

Habitat & Geographic Range

Common Seal

Habitat

Typically found in diverse ecosystems where prey species are available.

Range

Found across Europe (7 countries) and North America (United States). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Red-breasted Merganser

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Widely distributed across Asia (Taiwan), Europe (5 countries), North America (United States), and South America (Colombia).

Common Seal

The most widely distributed pinniped, harbor seals inhabit temperate and subarctic coastal waters of both the North Atlantic and North Pacific. Adults reach up to 130 kg and spend roughly equal time at sea hunting fish, squid, and crustaceans and hauling out on beaches or rocks to rest. Their large, expressive eyes are adapted for underwater vision in low light. Harbor seals are a critical food source for orcas, sharks, and polar bears.

Red-breasted Merganser

Red-breasted Merganser (Mergus serrator) is classified as Least Concern (LC) on the IUCN Red List. Widespread and abundant across its range, with stable populations and no immediate conservation concerns.

Shared Countries

Both species can be found in 6 countries:

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