VESPER SPARROWS. Pooecetes gramineus (Gmelin)²⁵

Field characters.—Size near that of Junco. Upper surface of body streaked with brown and black; under surface whitish, narrowly streaked on breast and sides with dark brown; outermost tail feather on each side mostly white (fig. 54b); patch at bend of wing bay-colored, though not so striking a mark as to be readily seen at any distance. Voice: Song of male somewhat like that of White-crowned Sparrow but yet distinct; two or three low clear notes, then two or more higher ones, and finally a succession of buzzy trills.

Occurrence.—Common summer visitant east of Sierras from Silver and Walker lakes eastward around Mono Lake (race confinis). Also winter visitant in moderate numbers on west side of mountains, where found at Lagrange and Dudley (race affinis). Frequents dry grassy ground, either entirely open or among scattering bushes. Met with singly or (in winter) in scattering assemblages.

---

²⁵ Two subspecies of the Vesper Sparrow occur in the Yosemite region. The WESTERN VESPER SPARROW, Pooecetes gramineus confinis Baird, a summer visitant to the Great Basin and known by its larger size and grayer tone of coloration, is to be found from May until September in the vicinity of Mono Lake. The OREGON VESPER SPARROW, Pooecetes gramineus affinis Miller, which summers in the western parts of Oregon and Washington and is known by its smaller size and warm brownish coloration, has been found as a winter visitant in the western part of the Yosemite section, more definitely, at Lagrange on December 19, 1915, and at Dudley, October 8, 1916. The differences between these races are so slight that individuals of the two would scarcely be distinguishable in the field, even should representatives chance to occur on common ground.

---

Several species of ground-dwelling sparrows with dull streaked pattern of coloration and of quiet or retiring disposition are found during certain seasons of the year at the lower altitudes on either side of the Sierra Nevada. At first glance they seem confusingly alike, but as the observer studies them closely and learns their peculiarities, each species is found to exhibit quite definite characteristics as to structure, coloration, and habits. The vesper sparrow is a member of this group.

The vesper sparrow in coloration combines streaking, both above and below, and a distinctly white-margined tail (fig. 54b), with the general features of a sparrow. In gross appearance it recalls the pipit, but it has none of the nervous 'wagtail' mannerism of that bird; indeed, the vesper sparrow gives one the impression of being unusually phlegmatic in disposition.

From the Savannah sparrow, which often occurs in company with, or on practically the same ground as, the vesper sparrow, the latter may be known by its larger size, relatively longer and white-bordered tail, and patch of bay color at the bend of the wing. The vesper sparrow frequents as a rule drier and more open situations where grass or other terrestrial vegetation is scantier; and it is somewhat less retiring in its behavior, than is the Savannah sparrow.

The habitat of the Western Vesper Sparrow during the summer months, in the Mono Lake country, is flat ground sparsely clothed with grass, and with scattered sagebrush or other small shrubs. On December 19, 1915, a far-scattered aggregation of about 50 Oregon Vesper Sparrows was found by Mr. Dixon on an open grassy area of about ten acres extent near Lagrange, exactly the same sort of country as that which was inhabited at that season by Western Savannah Sparrows. Mr. Donald D. McLean found this race once in the fall at Dudley (see footnote 25). The Western Vesper Sparrow, also, is to be expected at the west base of the Sierras in winter, but we ourselves failed to find it there.

The vesper sparrow gains its name from the supposition that the male bird sings at his best at early evening. During the spring months in the Mono country the males perch in the tops of sagebushes to sing, and from these vantage points, in our experience, they give voice to their rather stereotyped song quite as vigorously at one time of the day as another.

No nests of the Western Vesper Sparrow came to our attention, although near Rush Creek, on May 10, 1916, the males seen acted as though they had nests in the vicinity.

In the flock of Oregon Vesper Sparrows seen near Lagrange there was one individual much paler than the rest. This bird was shot and upon close scrutiny was seen to lack one of the component elements in its coloration, namely, the black pigment. The yellow pigment was present and the pattern developed, but the dark feather centers on the upper surface were wanting.