442 ANIMAL LIFE IN THE YOSEMITE 



close scrutiny was seen to lack one of the component elements in its color- 

 ation, namely, the black pigment. The yellow pigment was present and 

 the pattern developed, but the dark feather centers on the upper surface 

 were wanting. 



Savannah Sparrows. Passerculus sandwichensis (Gmelin)^* 



Field characters. — Smaller than Junco; tail shorter than body. No prominent white 

 markings on tail or wings. Upper surface streaked with black and various tones of 

 brown; lower surface of body white, with narrow streaks of dark brown on sides of 

 throat and on breast; a narrow stripe of light color runs backward over crown and 

 another over each eye, the latter stripe being bright yellow in some individuals (pi. %j). 

 Usually stays on ground, at most perching on weed stems or fence wires but a few 

 inches above the ground. Voice : Song of male ' dry, ' two or three sharp notes followed 

 by a buzzing sound; both sexes utter a weak sect. 



Occurrence. — Common winter visitant along west base of Sierra Nevada (race 

 alaudinus common, race sandwichensis rare) ; also common summer visitant in vicinity 

 of Mono Lake (race ncvadensis) ."^^ Inhabits open grasslands at all seasons. Sociable 

 but not definitely flocking in habit. 



The Savannah Sparrow finds the most congenial conditions both as to 

 shelter and food upon open meadow lands; here the birds are likely to 

 be found, either summer or winter, or during their migrations. Since 

 grassland of one variety or another is found over much of North America, 

 so are Savannah sparrows, represented by several geographic races. In 

 the Yosemite region two races or subspecies of the Savannah sparrow occur 

 in the winter months on the grass covered hillslopes and plains west of 

 the mountains, and a third is found about Mono Lake in the summertime. 



Savannah sparrows during most of the year are of a retiring dispo- 

 sition and if undisturbed will rarely come into prominent view. They 

 do not expose themselves as do brush or tree-dwelling species. If started 

 up from their favorite retreats they fly off quickly, in a jerky, hesitating 

 manner, and after proceeding a short distance in zigzag course, drop down 



26 Three subspecies of the Savannah Sparrow are found in the Yosemite region: 

 (1) Aleutian Savannah Sparrow, Fasserculus sandwi-chcnsiji sandwichcnsi.t (Gmelin), 

 which nests on the Aleutian Islands and which is distinguished by its relatively large 

 size, is a rare winter visitant, and was found only at Snclling, on January and 8, 

 1915; (2) Western Savannah Sparrow, Passercuhts sandirichcnsi.'< ahvidintts Bona- 

 parte, which summers in western North America (west and north of the CJroat Basin), 

 and which is characterized by intermediate size and coloration, is a common winter 

 visitant at Snelling and near Lagrange and Pleasant Valley and Avas once taken at 

 Smith Creek, 6 miles east of Coulterville; (3) Nevada Savannah Sparrow, Passercuhts 

 sandwichensis ncvadensis Grinncll, is a Great Basin race notable for its small size and 

 grayish coloration, and is found as a common summer visitant in the vicinity of Mono 

 Lake. One individual of this race was obtained by us at 9700 feet altitude above Ten 

 Lakes on October 11, 1915, and another was obtained by Mr. Joseph Mailliard (1918, 

 p. 17) in willows along Merced Eiver in Yosemite Valley, September 27, 1917. 



Sandivichensis is enough larger and slower in movement than nJandinuft to render the 

 two distinguishal)le when seen together in the field. NcvadcnMs is not likely <o be found 

 west of the Sierras in numbers at any time of year. By far the most plentiful race 

 west of the Sierras in winter is alaudiniis. 



