Common Merganser vs Guiana Dolphin

Mergus merganser compared with Sotalia guianensis

Key Differences

• Common Merganser is Least Concern while Guiana Dolphin is Data Deficient.

Taxonomic Classification

Rank	Common Merganser	Guiana Dolphin
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Aves (Birds)	Mammalia (Mammals)
Order	Anseriformes (Anseriformes)	Cetacea (Whales & Dolphins)
Family	Anatidae	Delphinidae (Oceanic Dolphins)
Genus	Mergus	Sotalia
Species	Mergus merganser	Sotalia guianensis

Evolutionary Relationship

Common Merganser and Guiana Dolphin share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Common Merganser

LC — Least Concern

Guiana Dolphin

DD — Data Deficient

Physical Characteristics

Attribute	Common Merganser	Guiana Dolphin
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Merganser

Habitat

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

Range

Found across Europe (5 countries) and North America (United States).

Guiana Dolphin

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia and Venezuela.

Common Merganser

<em>Mergus merganser</em>, the common merganser or goosander, is a large diving duck in the family Anatidae, broadly distributed across Europe and North America. It is classified as Least Concern on the IUCN Red List. This species is capable of aerial, terrestrial, and aquatic locomotion, but is most specialized for underwater pursuit of prey. The common merganser is typically piscivorous, diving in clear, fast-flowing rivers and lakes to catch fish using its serrated bill, which provides a firm grip on slippery prey. Males display striking breeding plumage with a dark green head, white body, and red bill, while females are grey with a rusty-brown head and crested nape. The species nests in tree cavities, cliff ledges, and artificial nest boxes near freshwater habitats. It requires clean, well-oxygenated rivers and lakes for foraging, making it sensitive to water quality degradation and overfishing of prey species. Common mergansers are migratory in northern parts of their range, moving to coastal and ice-free inland waters during winter months.