Martinet ramoneur vs Martinet à ventre blanc

Chimney Swift and Alpine Swift can be distinguished primarily by size and plumage. The Chimney Swift is smaller with a more uniform dark appearance, while the Alpine Swift is larger and features a distinct white belly and throat.

Look for the size difference; the Chimney Swift is smaller. Note the plumage: Chimney Swifts are uniformly dark, while Alpine Swifts have a white belly and throat.

The Chimney Swift is noticeably smaller than the Alpine Swift.

Chimney Swifts have a uniform dark plumage, whereas Alpine Swifts have a striking white belly and throat that contrast with their darker wings and back.