Rock ptarmigan Lagopus mutus

Identification Tips:

• Length: 11 inches
• Medium-sized, stocky, round-winged, chicken-like bird
• Squarish black tail
• Small black bill
• Legs and toes feathered to tips of toes in winter, base of toes in summer
• Brown or white uppertail coverts cover center of tail

Male alternate:

• Red comb over eye
• White wings and leg feathering
• Body brown barred with black or white depending on molt stage
• Black tail

Female alternate:

• Brown plumage with black spotting and barring
• Black tail

Basic:

• Entirely white plumage except for black tail
• Males, and some females, have black eyeline

Similar species:

The Rock Ptarmigan can be told from all plumages of the White-tailed Ptarmigan by its black, not white, tail. Male Willow Ptarmigans in alternate plumage have a redder plumage while male Rock Ptarmigans in basic plumage have distinctive black eyelines. Females are more difficult to tell apart but the Rock Ptarmigan has somewhat finer markings and a smaller black bill.

Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.