196 BULLETIN 162, UNITED STATES NATIONAL MUSEUM 



under a stunted hemlock. All the feathers were white, so the ptar- 

 migan must have laid early." 



There is a set of 11 eggs in Col. John E. Thayer's collection, taken 

 by John Koren on Kodiak Island, Alaska, on June 25, 1911. The 

 eggs were fresh and " were placed on a bed of moss in a two-foot 

 groove in an elevated part of the tundra "; both parents were present. 

 The eggs are not distinguishable from those of the willow ptarmigan. 

 The measurements of 20 eggs average 42.8 by 30.9 millimeters; the 

 eggs showing the four extremes measure 45.9 by 31.5, 43.6 by 32, 

 41.5 by 30.8, and 42 by 30.2 millimeters. 



Young. — Swarth (1924) writes: 



In all, ten broods of willow and rock ptarmigan were encountered (the species 

 were not always to be differentiated) and about five or six single birds in addi- 

 tion. The broods ranged from three to twelve in number ; the aggregate of young 

 birds seen was about fifty. The chicks grew rapidly. Some seen on July 25, 

 and a day or two later, were down-covered and unable to fly. At that time 

 they were accompanied by the female parent only, and the male birds were 

 flushed separately. By August 10 the young ptarmigan were the size of quail 

 and larger, and were strong on the wing. The old males were then associated 

 with the families. In some of the larger broods seen the difference in size 

 among the young was so marked as to suggest the junction of two families. It 

 might happen that upon the death of a hen her offspring would seek the com- 

 panionship of another family. 



Food. — These ptarmigan probably feed on as varied a diet as other 

 ptarmigan, but the following note by Alfred M. Bailey (1927) is all 

 that I can find in print on the subject : 



A flock was flushed from a bed of wild strawberries, at an altitude of scarcely 

 thirty feet, when I had expected to find them above timber line. There were 

 several pairs of adults, as well as many young, and a good series was taken. 

 An examination of crop contents proved the birds had been feeding eutirely on 

 strawberries and pea-vine, no alder or willow buds being found. After finding 

 ptarmigan in such a low altitude, I searched all the points along the east main- 

 land shore, and did not fail once to find them, where there were berries. It 

 was noticeable they preferred the points where they could feed close to a 

 fringe of alder. 



Behavior. — Mr. Bailey (1927) says also: 



I returned to Glacier Bay again from October 10-14, and observed the Ptar- 

 migan under still different conditions. A stop was first made on the outer 

 Beardslee, upon which the young bird had been taken. I was interested to see 

 if the Ptarmigan had left the island, as it was now drab and dry looking, and 

 the birds were assuming their winter's white. I found them very abundant, and 

 over forty were flushed from the dense alders, and a few taken. They were 

 extremely wild, as they should have been, for their changing plumage — entirely 

 white below with many white feathers in head and neck, made them extremely 

 conspicuous among the leafless alders. I had little chance to observe them, du<* 

 to their wildness. Stops were made at two other points, not visited in August, 

 and ptarmigan were noted in both places. At Sandy Cove, October 14, I col- 

 lected another series from the point they were first found in August. These 



