Common Eider vs Chestnut-sided Warbler

In short

The Common Eider and Chestnut-sided Warbler are easily distinguished by size and habitat. The Eider is a large sea duck, while the Warbler is a small, colorful songbird found in forests. Their plumage and behaviors are also distinct, making them unlikely to be confused in the field.

Identification tips

1. Size and Shape: Look for the large size and duck-like shape of the Eider compared to the small, agile form of the Warbler. 2. Habitat: Note the coastal presence of Eiders versus the forest habitat of Warblers. 3. Plumage: Check for the Eider's black and white coloration versus the Warbler's yellow and chestnut tones. 4. Behavior: Observe the Eider's diving behavior compared to the Warbler's active foraging and tail-cocking. 5. Vocalization: Listen for the Warbler's distinctive song, absent in Eiders.

Size

The Common Eider is significantly larger, about the size of a goose, whereas the Chestnut-sided Warbler is a small bird, similar in size to a sparrow.

Plumage

The Common Eider has a predominantly white and black plumage with a distinctive sloping forehead and greenish nape in males. The Chestnut-sided Warbler is much smaller with a striking yellow crown, white underparts, and chestnut flanks.

Behaviour

Common Eiders are often seen in groups on coastal waters, diving for food. Chestnut-sided Warblers are active foragers, moving through foliage with a distinctive tail-cocking behavior.

Habitat

Common Eiders inhabit coastal marine environments, often seen on rocky shores or open water. Chestnut-sided Warblers prefer deciduous forests and shrubby areas, especially during migration and breeding seasons.

Voice

Common Eiders are generally silent but may produce low cooing sounds. Chestnut-sided Warblers have a distinctive song, often transcribed as "please, please, pleased to meetcha," used to attract mates and establish territory.