Common Scoter vs Black Scoter

In short

The Common Scoter and Black Scoter are similar sea ducks, but can be distinguished by bill color and shape. The Common Scoter male has a yellow patch on the bill, while the Black Scoter male's bill is mostly yellow with a black tip. Females are more challenging to differentiate but look for subtle differences in head shape and bill base feathering.

Identification tips

1. Bill Color: Male Common Scoter has a yellow patch on the culmen; male Black Scoter's bill is mostly yellow with a black tip. 2. Female Identification: Look for the shape of the bill base feathering; Common Scoter females have a straighter or slightly convex feathering, while Black Scoter females have a concave feathering. 3. Vocalization: Listen for the Black Scoter's distinctive whistling, especially in groups.

Size

Both species are similar in size, with the Common Scoter having a wingspan of 79–90 cm.

Plumage

Male Common Scoters are sooty black with a yellow patch on the culmen, while male Black Scoters have a more prominent yellow bill with a black tip. Female Common Scoters are dark brown with a less contrasting cap and cheeks compared to the Black Scoter females.

Behaviour

Both species are often found in large flocks at sea, especially during winter. They have similar flight patterns, being fast and direct.

Habitat

Both species inhabit coastal waters, but the Common Scoter is more frequently found in the Western Palearctic, while the Black Scoter is found in North America.

Voice

The Black Scoter is more vocal, with males producing a mellow, plaintive whistle. Common Scoters are usually silent but can produce thin, piping whistles.