Commerson s Dolphin vs Common Scoter

Cephalorhynchus commersonii compared with Melanitta nigra

Taxonomic Classification

Rank	Commerson s Dolphin	Common Scoter
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Aves (Birds)
Order	Cetacea (Whales & Dolphins)	Anseriformes (Anseriformes)
Family	Delphinidae (Oceanic Dolphins)	Anatidae
Genus	Cephalorhynchus	Melanitta
Species	Cephalorhynchus commersonii	Melanitta nigra

Evolutionary Relationship

Commerson s Dolphin and Common Scoter share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Commerson s Dolphin

LC — Least Concern

Common Scoter

LC — Least Concern

Physical Characteristics

Attribute	Commerson s Dolphin	Common Scoter
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Commerson s Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Common Scoter

Habitat

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

Range

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

Commerson s Dolphin

<em>Cephalorhynchus commersonii</em>, commonly known as Commerson's Dolphin, is a small cetacean in the family Delphinidae. This species is classified as Least Concern on the IUCN Red List and is notable for its striking black-and-white coloration, which makes it one of the most visually distinctive dolphin species. Commerson's Dolphins typically inhabit coastal and nearshore marine environments of the Southern Hemisphere, particularly around the Falkland Islands, the southern tip of South America, and a geographically isolated population near the Kerguelen Islands in the Indian Ocean. These dolphins are highly social animals, often observed in small groups engaging in acrobatic behaviors near the surface. They typically feed on fish, squid, and crustaceans, often hunting cooperatively in shallow waters and kelp beds. Their average lifespan is approximately 18 years, and they are known for their fast, energetic swimming. Commerson's Dolphins are sometimes caught as bycatch in fishing nets, posing a localized conservation concern despite their overall Least Concern status.

Common Scoter

<em>Melanitta nigra</em>, the common scoter, is a sea duck in the family Anatidae, order Anseriformes, breeding across subarctic and boreal regions of Europe and northeastern North America. This species winters primarily along coastal marine environments, with records from Belgium, Denmark, Norway, Sweden, and the United States reflecting both breeding and wintering distributions. The common scoter typically nests near freshwater lakes and bogs in boreal and tundra habitats, migrating to sheltered coastal bays and estuaries during winter where it dives for bivalves, crustaceans, and other benthic invertebrates. Males are predominantly black with a characteristic orange-yellow knob at the base of the bill, while females are brown with pale cheek patches. <em>Melanitta nigra</em> is listed as Least Concern by the IUCN, though populations have experienced declines in some regions due to changes in wintering habitat quality and food availability. Biological traits for this species remain poorly documented in the scientific literature, including comprehensive data on average lifespan, body length, weight, and full dietary composition across seasons.