116 BULLETIN" 16 2, UNITED STATES NATIONAL MUSEUM 



to them, and they continued long after we finished this record. The ventrilo- 

 quial quality is discovered when one attempts to locate the producer, a difficult 

 feat as a rule. The observer may succeed in locating the proper tree, but is 

 likely to circle it many times, peering upward with painfully aching neck, and 

 still utterly failing to locate the avian performer amid the foliage high over- 

 head. The notes are commonly supposed to be produced by the bird's inflating 

 and exhausting the glandular air sacs on the sides of the neck. These sacs are 

 covered by unfeathered yellow skin, and we think it more likely that they 

 serve only as resonators, being kept continually inflated, while the air actually 

 producing the sound passes to and from the lungs along the regular air pass- 

 age. It rests with some one gifted with patience for long-continued observa- 

 tion to determine exactly how the notes are produced. 



W. Leon Dawson (1923) also says: 



As the hooter becomes vehement he struts like a turkey-cock, spreading the 

 tail in fan-shape, dropping the wings till they scrape the ground, and inflating 

 his throat to such an extent as to disclose a considerable space of bare orange- 

 colored skin on either side of the neck. This last certainly makes a stunning 

 feature of the gallant's attire, for Nature has contrived that the feathers 

 immediately surrounding the bald area should have white bases beneath their 

 sooty tips. During excitement, then, as the concealing feathers are raised and 

 reversed, a brilliant white circlet, some five inches in diameter, suddenly flares 

 forth on each side of the neck, to the great admiration, no doubt, of the 

 observant hen. 



These more emphatic demonstrations are probably reserved for such time 

 as the hen is known to be close at hand, for I have never frightened a strut- 

 ting cock without finding a female hard by, at least at no greater distance than 

 the lower branches of a neighboring tree. She has responded to the earlier 

 calls of the male by a single musical toot note, uttered at intervals of ap- 

 proach ; but once arrived at the trysting place she has become very shy, and 

 will take no part in the celebration, save by a few tell-tale clucks and many coy 

 evasions. On these occasions, also, the cock works himself up into such a 

 transport that he becomes oblivious to danger, so that he may be narrowly 

 observed or even captured by a sudden rush. 



Nesting. — The nesting habits of the Sierra grouse are similar to 

 those of other forms of the species. Mrs. Irene G. Wheelock (1904) 

 writes : 



In May or June, according to location, the wooing begins, and soon the mother 

 is brooding on her eight buffy eggs in the shade of a fern tangle, near a log, 

 or in a clump of manzanita. No part does the father take in the three weeks 

 of patient incubation, but the mother can seldom be surprised away from the 

 nest. It would be far easier to discover the eggs were she not covering them, 

 for so protective is her coloring that you may be looking directly at her and 

 never suspect it, although at that very moment you are searching for a nest. 

 Her food is all about her — buds, berries, and insects. If she leaves the eggs, 

 it is only to stretch her tired little legs and pick up a few dainties close by. 



Eggs. — The eggs of this grouse are indistinguishable from those 

 of other races of the species. The measurements of 23 eggs average 

 48.7 by 35.2 millimeters ; the eggs showing the four extremes measure 

 45.1 by 34.3, 49 by 37.5, 51.2 by 34.6, and 46.1 by 32.8 millimeters. 



