Nov., 1915 
NESTING OF THE WHITE-TAILED PTARMIGAN 
215 
level), the party worked steadily upward until they reached, on June 10, St. 
Mary’s Lake, a small body of water at the foot of a glacier in Clear Creek 
County (altitude about 10,800 feet). Here camp was located to allow of hunting 
for the White-tailed Ptarmigan ( Lagopus leucurus), Leucosticte, Pipit, and 
other species nesting at and above timber-line (at this point, about 11,000 feet 
altitude), and for the Kinglet, Hermit Thrush, and other species nesting shortly 
below timber-line. The party spent several days, prior to my arrival there on 
June 20, in a fruitless search for nests of the ptarmigan, although daily seeing 
more or less of the birds. 
Owing to this location being adjacent to some of the oldest mining centers 
in the state, the birds are scarce; but mining friends having reported seeing a 
few months previously several flocks in the full white winter plumage, I selected 
this site for work. This was desirable also on account of accessibility, we being 
Fig. 71. Nesting ground of White-tailed Ptarmigan, at 11500 feet 
ALTITUDE IN CLEAR CREEK COUNTY, COLORADO; NEST AND EGGS 
TAKEN NEAR HERE JUNE 26 , 1915 . ROCK-PILE IN BACKGROUND FRE- 
QUENTED by Brown-capped Rosy Finches. 
able to get by wagon nearly to the camp site above referred to. 
Immediately upon my arrival we devoted our entire attention to search for 
ptarmigan nests, as neither our museum nor myself had a representation of the 
eggs of this species. As these birds do not nest in this state below timber-line, 
our easiest approach to their nesting grounds was by foot up a glacier approxi- 
mately a mile long, which landed us upon a wide expanse of comparatively flat, 
rolling ground, terminating at the base of James Peak and Mount Bancroft, 
and covered with the short grass and other scrubby plant growth peculiar to that 
altitude. Much of this tract was still covered with snow, and the balance mostly 
wet and sloppy from the melting drifts, thus making it necessary to wear rubber 
or other water-proof boots. 
Being but little conversant with the nesting habits of these birds, we nat- 
