WILLOW PTARMIGAN I7I 
puts a temporary stop to their proceedings. About 
the fifth or fifteenth of this month the first dark feath- 
ers commence to appear about the heads and necks of 
the males. During some seasons the males make 
scarcely any progress in changing their plumage up 
to the middle of May, when I have frequently seen 
them with only a trace of dark about the head and 
neck. In the spring of 1878 the first males were heard 
calling on the 26th of April, and on April 27th, in 
1879, the males were just commencing to moult, show- 
ing a few dark feathers, but these seasons were un- 
usually late. In autumn the change frequently com- 
mences the last of September and by the first of 
October it is well under way, the winter moult being 
completed toward the end of this month. ... 
“At the Yukon mouth, on the evening of May 24th, 
these ptarmigan were heard uttering their hoarse notes 
all about. As we were sitting by the tent my in- 
terpreter took my rifle and, going off a short distance, 
worked a lump of snow to about the size of one of 
these birds. Fixing a bunch of dark-brown moss on 
one end of the snow to represent the bird’s head, he 
set his decoy upon a bare mossy knoll; then retiring a 
short distance behind the knoll he began imitating the 
call of the male until a bird came whirring along and 
taking up the gauntlet lit close by this supposed rival 
and fell a victim to the ruse. 
- At this time the males were continually 
pursuing each other or holding possession of prominent 
knolls, frequently rising thence five to ten yards in 
