The Western Grasshopper Sparrow 

 No. 44 



Western Grasshopper Sparrow 



A. 0. U. No. 546a. Ammodramus savannarum bimaculatus (Swainson). 



Description. — Adults in spring: Crown brownish black, parted by a median 

 stripe of buffy gray; nape olive-gray, spotted with dark cinnamon; remaining upper- 

 parts black and fuscous, feathers edged with light olive-gray and tipped with cinnamon 

 in varying proportions (a single feather, as from the greater wing-coverts, will exhibit 

 the four colors); below cinnamon-buffy, brightest on the breast, clearing to whitish 

 on lower breast and belly; the sides and flanks darker; an elongated spot over the eye, 

 bend of wing, and edge of wing near alula, yellow. Bill horn-color above, yellow 

 below; feet yellow. In winter: plumage softer and more blended by reason of increase 

 of the cinnamon-buffy element, which now appears as additional margining of feathers 

 above. Young birds are heavily spotted with blackish across the chest. Length of 

 adult male 123. 2-132 (4.85-5.20); wing 62.5 (2.46); tail 46.5 (1.83); bill 10.9 (.43); 

 tarsus 19.6 (.77). 



Recognition Marks. — Warbler size; unmarked below; bright yellow edge of 

 wing; grasshopper notes; an obscure, close-hiding terrestrial species. 



Nesting. — Nest: On the ground; a cup of coiled, dried grasses, sunk flush with 

 surface and usually well concealed in grass or other vegetation. Eggs: 4 or 5; short- 

 ovate, sometimes rounded; clear white, sharply and moderately, or heavily, speckled 

 and spotted, chiefly at larger end, with reddish brown (burnt umber to pecan brown); 

 av. size 18.8 x 14.2 (.74 x .56). Season: April to June, but chiefly May; one or two 

 broods. 



Range of A. savannarum. — United States south to West Indies, Central America, 

 and northern South America. 



Range of A. s. bimaculatus. — Western North America, breeding from south- 

 eastern British Columbia, northern Montana, and southern Minnesota, south to 

 southern California and Texas. Winters from central California, southern Arizona, 

 and southern Texas, to Cape San Lucas and Central America. 



Distribution in California. — Partially resident or summer resident, irregu- 

 larly and locally, in meadows and lowlands, or on open grassy hillsides west of the 

 Sierras, from Sacramento and Mendocino counties (Ukiah, June 13, 1916) south to 

 San Diego; more widely distributed in winter. 



Authorities. — Heermann (Emberiza passerina) , Journ. Acad. Nat. Sci. Phila., 

 ser. 2, vol. ii., 1853, p. 265; Henshaw, Rept. Orn. Wheeler Surv., 1876, pp. 240-241 

 (nesting at Santa Barbara); Willett, Condor, vol. xii., 1910, p. 204; Pac. Coast Avifauna, 

 no. 7, 1912, p. 78 (nesting in so. Calif.); Tyler, Pac. Coast Avifauna, no. 9, 1913, pp. 

 78-79 (habits); Dixon, Condor, vol. xviii., 1916, pi. 84 (nesting at Escondido) ; Pember- 

 ton, Condor, vol. xix., 191 7, pp. 24-25 (nesting in Santa Monica Mts.). 



"THOSE bird-lovers who disclaim all interest in entomology will be 

 slow in discovering this humble species, for its song is nearer like the 

 chirring of some insect than the voice of a bird. There always comes a 

 day in late April when the half-grown meadows and fields are suddenly 

 found to contain from one to six pairs each of these buzzing Sparrows. 



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