SAGE HEN 305 



buffy and more spotted than barred ; the feathers of the black breast 

 patch are tipped with white; and the feathers of the mantle are 

 conspicuously marked with a broad shaft streak of white. Young 

 males seem to be much darker than young females. 



A nearly complete postjuvenal molt, including all but the outer 

 two primaries on each wing, produces the first winter plumage, which 

 is practically adult and in which the sexes are fully differentiated. 

 There may be a partial prenuptial molt, but I have seen no evidence 

 of it in either young or old birds. Adults have a complete post- 

 nuptial molt, mainly in August. 



Food. — Dr. Sylvester D. Judd (1905a) says: 



The feeding habits of the sage grouse are peculiar, and its organs of digestion 

 are unlike those of other grouse. The stomach is not differentiated into a 

 powerful grinding gizzard, but is a thin, weak, membranous bag, resembling 

 the stomach of a raptorial bird. Such an organ is evidently designed for the 

 digestion of soft food, and we find that the bulk of the sage grouse's diet con- 

 sists of leaves and tender shoots. A stomach collected September 7, 1890, in 

 Idaho, by Dr. C. Hart Merriam, contained leaves of sage and other plants, 

 seeds, and a ladybird beetle (Coccinellidae). Four birds shot in Wyoming 

 during May and September by Vernon Bailey had gorged themselves with the 

 leaves of sagebrush (Artemisia tridentata). This and other sages, including 

 A. cana and A. frigida, furnish the bulk of the food of the sage grouse. Other 

 food is taken, but it is comparatively insignificant. B. H. Dutcher, formerly of 

 the Biological Survey, examined a stomach which, besides sagebrush leaves, 

 contained seeds, flowers, buds of Rhus trilobata, and ants and grasshoppers. 

 Three birds collected by Vernon Bailey on September 5, in Wyoming, had varied 

 their sagebrush fare with ladybird beetles, ground beetles (Carabidae), fly 

 larvae, ants, moths, grasshoppers (Melanvplus sp.) and the leaves of asters 

 and yarrow. Of two birds killed in May, one had fed wholly on the leaves 

 of sagebrush (Artemisia tridentata), while the other in addition had taken 

 insect galls from sagebrush and the flowers and flower buds of a phlox (Phlox 

 douglasii), together with some undetermined seed capsules, pieces of moss, and 

 several ants. A third bird, killed in July, had eaten a few plant stems and 

 numerous grasshoppers. 



During the winter the sage grouse feeds almost entirely on the 

 leaves of the sage, but "in summer," according to Bendire (1892), 

 " its principal food (in Wyoming and Colorado) is the leaves, blos- 

 soms, and pods of the different species of plants belonging to the 

 genus Astragalus, and Vicia, commonly called wild pease, which are 

 always eagerly sought for and consumed in great quantities." 



Eobert S. Williams reported to Bendire from Montana that he 

 scared up a flock among tall grass in a mountain meadow; one of 

 these birds had its crop full of the blossoms of a species of golden- 

 rod. Bendire also quotes George H. Wyman as stating that a sage 

 grouse will go a long way for food in a wheat field; some that he 

 examined had traveled at least 8 miles to till their crops with ripe 

 wheat. 



