548 GAME BIRDS OF CALIFOENIA 



experience and knowledge of the blue grouse's habits. Then [suddenly] . . . 

 they burst forth with a startling whir of wing-beats, and after gaining full speed 

 go skating s\\'iftly away through the forest arches in a long, silent, wavering 

 slide with wings held steady. 



During the summer they are most of the time on the ground, feeding on insects, 

 seeds, berries, etc., around the margins of open spots and rocky moraines, playing 

 and sauntering, taking sun baths and sand baths, and drinking at little pools 

 and rills during the heat of the day. In winter they live mostly in the trees, 

 depending upon buds for food, sheltering beneath dense overlapping branches at 

 night and during storms on the lee side of the trunk, sunning themselves on the 

 southside limbs in fine weather, and sometimes diving into the mealy snow to 

 flutter and wallow, apparently for exercise and fun. 



The flight of the Sierra Grouse is rapid and direct, with fast 

 beating wings. When flushed at short range, the swift movement, 

 and rapid whirring of the wings necessary to lift the bird's heavy- 

 body, produce a startling sound, and with a small flock the aggregate 

 noise is most bewildering to an intruder. 



It is during the spring and early summer, the courting season, 

 that the voice of the Sierra Grouse is most frequently heard. Males 

 are in the habit of taking positions near the tops of pines or firs, 

 sixty or seventy feet above the ground, standing close to the trunk on 

 some horizontal limb. Such a station will be held continuously for 

 hours, and from it the reverberant hooting is heard at varying inter- 

 vals. The hooting may be described as a deep, wooden, far-carrying, 

 ventriloquial sound. The sequence of notes has been recorded as: 

 unt, wunt, wunV , wunf , tu-ivunV , wunt, want (Storer, MS) ; another 

 rendering is hoont, hoont, hoont' , hooriV, hoont, hoont, six of these 

 notes seeming to be the average in the case of two birds under obser- 

 vation. In different individuals the series consisted of five to seven 

 notes, in quality of sound likened to beating on a sodden wooden tub, 

 crescendo in volume, diminuendo towards the end of the series ( Grin- 

 nell, MS). As each note is uttered the tail of the bird is seen to be 

 depressed an inch or two — an index to the effort involved. The sepa- 

 rate series of notes in two cases under observation were uttered at 

 intervals of seconds as follows: 40-20-25-45-12-21-29; and again: 

 10-10-20-26-14-15-17-12-11-15-13-28-17-11 (Storer, MS). The 

 ventriloquial quality comes into evidence when one attempts to locate 

 the producer, a very difficult feat as a rule. The observer may circle 

 the tree many times with a painfully aching neck and still utterly 

 fail to locate the bird amid the foliage high overhead. The notes are 

 commonh^ supposed to be produced by inflating and exhausting the 

 glandular sacs on the sides of the neck, which are covered by un- 

 feathered yellow skin. We think it likely that, in fact, these sacs 

 serve only as resonators, being kept contiiuuilly inflated, while the 

 air producing the sound passes to and from the lungs along the 



