Red-breasted Merganser vs Scaly-sided Merganser

In short

The Red-breasted Merganser and Scaly-sided Merganser are both diving ducks with distinct features. The Red-breasted Merganser is more widespread and typically found in northern coastal areas, while the Scaly-sided Merganser is rarer and primarily inhabits fast-flowing rivers in East Asia. Key differences include bill color and plumage patterns.

Identification tips

1. Bill color: Red-breasted Merganser has a red bill, while Scaly-sided Merganser's bill is more orange. 2. Plumage pattern: Look for the scaly pattern on the flanks of the Scaly-sided Merganser. 3. Habitat: Consider the habitat; Scaly-sided Mergansers are more likely in fast-flowing rivers, whereas Red-breasted Mergansers are often in coastal areas. 4. Crest: The Red-breasted Merganser has a spiky crest, which is less pronounced in the Scaly-sided Merganser.

Size

Both species are similar in size, but the Red-breasted Merganser may appear slightly more elongated due to its longer neck and body.

Plumage

The Red-breasted Merganser has a distinctive spiky crest and a reddish-brown breast, especially in males. In contrast, the Scaly-sided Merganser features a unique scaly pattern on its flanks and lacks the pronounced crest. Females of both species are more subdued, but the Scaly-sided female's flank pattern remains a key identifier.

Behaviour

Both species are diving ducks that forage for fish, but the Scaly-sided Merganser is more often found in fast-flowing rivers, while the Red-breasted Merganser is more coastal.

Habitat

The Red-breasted Merganser is typically found in coastal bays and large water bodies in the tundra and boreal forest zones. The Scaly-sided Merganser prefers fast-flowing rivers in forested areas of East Asia.

Voice

Vocalizations are not a primary distinguishing feature between these two species, and there is limited information on differences in their calls.