98 BULLETIN 162, UNITED STATES NATIONAL MUSEUM 



is only when birds are disturbed and driven from the peak that they will at- 

 tempt to cross to the southern ridge during the middle of the day. Through- 

 out the day grouse are arriving along the upper slopes of Baldy, singly, in pairs, 

 and small flocks that have perhaps formed since the southward march began, 

 as I think they do not winter in company, but the flight from the peak is usually 

 in flocks of from a dozen to a hundred birds. Though the ridge south of Sparta 

 is 400 feet or more lower than the top of Baldy, it is fully a mile and a half 

 distant in an air line, and the flight is seldom sustained to carry the birds 

 to the top. Usually they alight on the snow half way up the slope, and after 

 a few moments' rest, continue the journey on foot ; those passing over in the 

 evening spend the night, I think, in the pines, the last of which are seen along 

 this divide ; but those arriving in the morning soon pass on, walking down any 

 of the small ridges leading toward Powder River. 



Courtship. — Maj. Allan Brooks (1926) has published a full account, 

 with illustrations, of the courtship display of this grouse, from which 

 I quote, as follows: 



His first position was a crouching one, the tail spread to extreme extension 

 cocked right over the back and a little to one side, the neck feathers showing 

 as a snowy mass, with the red gular sac looking like a small oyster on a 

 large shell. 



He maintained this attitude for several minutes, then the head was raised, 

 the neck swelled, and he turned towards me and commenced to nod his head ; 

 the gular sacs were a deep purple-red, the " combs " over each eye changed from 

 yellow to a dusky orange and were inflated to the extent that they almost met 

 on the crown, and the inversion of the neck feathers showed as a huge blaze of 

 white on each side. After six or eight nods the head was lowered to within 

 two inches of the ground and with the neck inflated until the sacs showed a 

 diameter of three inches, the tail still elevated and spread to its full extent, the 

 feathers of the lower back standing on end, the wings trailing on the ground, 

 the bird made a short quick run of six or eight steps curving to the right and 

 emitted the deep Oop! 



Brooks compares the hooting of Richardson's grouse with that of 

 the sooty grouse, as follows : 



Often in later years a male Richardson's Grouse has been seen uttering his 

 low hooting, similar to the resonant hooting of the Sooty Grouse (Dendragapus 

 obscurns fuliginosus) but with only a small fraction of its volume. In my 

 experience Richardson's Grouse always utters this hooting from the ground. 

 The tempo is the same as in the Sooty Grouse, five or rarely six deliberate evenly 

 spaced hoots or grunts — Humph-humpJi-humphr-ma-h.umph-humph — but the 

 sound is barely audible up to 75 yards or so. In the Sooty and Sierra Grouse 

 this chant assumes a dominant character, ventriloquial to a degree it sounds 

 far off when quite near and yet has a carrying power of at least 2 miles. In 

 neither species is the tail very widely spread when uttering, nor is there any 

 special posture or action excepting a crouching attitude, high up in a coniferous 

 tree in the Sooty Grouse, and on the ground, usually on some rocky ridge, In 

 Richardson's. The Sooty Grouse also has the single Oop! although I have rarely 

 heard it and then only late in the breeding season. 



A very pronounced distinction in the two species, however, is the nature of 

 the gular air sacs. In the Sooty Grouse and allied races these in the breeding 

 season become cellular, gelatinous masses, capable of great distention, and the 

 exterior surface is velvety, deeply corrugated, and of a deep yellow color. In 



