Stejneger's Scoter vs Black Scoter

Stejneger's Scoter and Black Scoter are both sea ducks with similar dark plumage but can be distinguished by bill shape and vocalizations. Stejneger's Scoter has a more pronounced, knobbed bill, while Black Scoter males are known for their distinctive whistling calls.

1. Bill Shape: Look for the more pronounced, knobbed bill of Stejneger's Scoter compared to the smoother bill of Black Scoter. 2. Vocalizations: Listen for the distinctive whistling of Black Scoter males. 3. Location: Consider the geographic range; Stejneger's is more common in the North Pacific, while Black Scoter is found in the North Atlantic and parts of the Pacific. 4. Flock Behavior: Observe flock composition; Black Scoter often feeds in monospecific flocks.

Both species are similar in size, typical of medium-sized sea ducks.

Adult males of both species are predominantly black. Female Stejneger's Scoter has a dark brown plumage with a contrasting dark cap and lighter cheeks, similar to the female Black Scoter, making females harder to distinguish by plumage alone.

Both species often form large flocks, particularly in winter and during molting. Black Scoter tends to feed in monospecific flocks.

Both species are found in coastal waters, with Stejneger's Scoter primarily in the North Pacific and Black Scoter in the North Atlantic and parts of the Pacific.

Black Scoter males are notably vocal, producing a mellow, plaintive whistling sound, which can help differentiate them from the generally quieter Stejneger's Scoter.