Two subspecies recognized:
A. t. torda
A. t. islandica

Also known as Razor-billed Auk
 

Identification

Figure 1. Alternate plumage Razorbill (Alca torda) with Common Murres (Uria aalge). Photograph copyright of Jeremy Barker© (1999), all rights reserved.
 

Where and When

Photographs on the web

Breeding adults Photograph by John Chardine, taken on Great Island, Newfoundland.

Superb shots of an alternate-plumaged adult showing the ventral surface and the dorsal surface. Photos by Arthur Morris and hosted by Don Crockett/The Virtual Birder.
 

Literature

Gaston, A. J. and Jones, I. L. (1998) The Auks. Bird Families of the World 4. Oxford University Press.