THE WILLOW PTARMIGAN 



By JOSEPH GRINNELL* 



^^t il^ational Sifisomtion ot Audubon ^ocittitfi 



EDUCATIONAL LEAFLET NO. 61 



The word Ptarmigan is applied to several species and races of grouse-like 

 birds comprising the genus Lagopus. The name was chosen appropriately, for 

 "Lagopus" signifies "rabbit-foot," and refers to the chief character by which 

 Ptarmigan are distinguished from other members of the Grouse family, namely, 

 the heavy clothing of hair-like feathers which envelop the feet. In all but one 

 of the species there are remarkable changes of plumage twice a year, through 

 which there is acquired for the winter season a snow-white dress. This, and 

 the fact that Ptarmigan Hve in the far north or on the tops of high moim- 

 tains, where the climate is severe, probably gave basis for the other name, 

 Snow Grouse, used commonly for the birds in some parts of their range, as in 

 Alaska. 



In America there are three distinct species of Ptarmigan. One of them, the 

 White-tailed, lives upon the snowy summits of the Rocky Mountains south as 

 far as northern New Mexico. The Rock Ptarmigan inhabits the mountainous 

 country farther north, and, as represented by various subspecies, is found 

 from Greenland, across the continent and on nearly every one of the long chain 

 of Aleutian Islands. The third American species, the Willow Ptarmigan, 

 with which the present essay is concerned, is most abundant on that level or 

 rolling arctic prairie-land known as tundra. This tundra extends almost 

 unbrokenly clear across North America from Labrador to western Alaska, 

 and may be said, in a general way, to occupy the interval between the tree 

 limit and the Arctic Ocean. In western and northern Alaska, these tundras 

 are covered with a deep layer of moss and lichens. Here or there in 'draws' or 

 shallow valleys, there are tracts of dwarf willow and alder. In summer the 

 tundras are boggy, and the numerous ponds and connecting channels make 

 traveling difficult. In winter they are frozen solidly, and the wind-driven snow 

 packs into the depressions so that the surface is nearly smooth. 



Save for black tail-feathers, almost completely concealed when the bird is 

 at rest, and the black of bill and eyes, the Willow Ptarmigan in the winter 

 season is pure white. When the white feathers first appear, in the fall, they 

 possess a perceptible, though faint, tinge of pink; but this soon fades out. 



The pure white winter dress is believed to make the birds so inconspicuous 

 against the white of the landscape that they many times escape discovery by 

 their enemies, the arctic fox and gyrfalcon, as they certainly do by the human 

 hunter. On a day when the sky is overcast with dense haze, obscuring the 

 direct rays of the sim, and dispersing an intense, even Ught, the Ptarmigan 



*Contribution from the Museum of Vertebrate Zoology of the University of California. 

 (376) 



