604 ANIMAL LIFE IN THE YOSEMITE 



fox sparrows may forage over the same ground, but they are after seeds, 

 which they get at by scratching. The thrushes do not use their feet at all 

 for uncovering food. The thrushes' legs are relatively long, so that the 

 birds stand high, and have consequently an increased scope of vision. 



If a hermit thrush is come upon while not busy foraging, the bird will 

 often stand quietly on its perch and watch the passer-by seemingly with 

 wide-eyed curiosity. Close approach is often permitted, especially on dull 

 days, though there is no reason to suppose that the thrush is less able to 

 see well then than in bright sunlight. In fact the reverse may be true, 

 for hermit thrushes are most conspicuously active at dusk. In this con- 

 nection attention may be called to the fact that thrushes in general are 

 big-eyed as compared with finches of equal bulk. (See fig. 59.) 



Fig. 59. Heads of (a) Sierra Hermit Thrush and (b) Cassin Purple Finch, natural 

 size, showing the relatively large eye of a shade-inhabiting bird (Thrush) as contrasted 

 with that of a species which lives chiefly in the open (Purple Finch). Also the differ- 

 ence in bill is shown between an insect- and berry-feeding bird as contrasted with bud- 

 and seed-eater. 



Every kind of bird has some feature of exceptional interest to the 

 bird student. "With some species it is brilliancy of plumage, with others 

 peculiarity of nesting habits. "With the plainly-garbed and retiringly- 

 disposed hermit thrush it is the bird's song which attracts and holds our 

 interest. Few if any among the birds of the region excel the hermit 

 thrush in impressiveness of song. The utterance is clear, highly musical 

 and agreeable to our ears, not especially joyful but inducing in the human 

 listener a pleasant reverie. Structurally, the song is varied, not at all 

 monotonous as is that of the robin. It consists of phrases separated by 

 rests of one to two seconds duration, each phrase consisting of three to 

 six syllables. Successive phrases are pitched on different keys, one low, 

 another high, a third midway of the bird's scale. Each begins with a clear 

 full-toned whistled or flute-like syllable and ends with a tinkle, in quality 

 suggesting an overtone. The notes of one bird listened to at Chinquapin 

 were written : sur-wheel-yer-eel-ye7'; poor, aurelia-elio; seer, eetle-eetle; sir, 

 wortle-ortle; per, wheetly-eetly, etc. When singing a thrush will sit motion- 

 less near the top of a small tree and may maintain its perch there for a 

 long period of time, though not continually in voice. The song season lasts 

 from some time in spring until early July, our latest record being of a 

 bird's singing at Tuolumne Meadows on July 8 (1915). 



