CALIFORNIA EVENING GROSBEAK Hesperiphona vespertina californica Grinnell

Field characters.—Size large for a Sparrow, but less than that of Robin. Body chunky, tail short and indented at end; bill very large and conical (fig. 52b). Male: Body coloration brownish yellow; tail and wings black, each wing with a large white patch (mostly on innermost secondaries); top of head black; forehead and stripe over eye clear yellow. Female: Body coloration grayish brown; wings and tail black, much spotted with white. Voice: Song of male three loud high-pitched notes uttered slowly: zer-r-p, zir-r-p, prilip; call note a shrill quer-up or killip, or plee-ek.

Occurrence.—Irregular, usually sparse, summer visitant to Transition and Canadian zones on west slope of Sierra Nevada. Observed from Crane Flat, Hazel Green, and Chinquapin east to Mono Meadow; also in Yosemite Valley. Irregular winter visitant to foothills, as at Smith Creek. Inhabits forest trees, foraging in crown foliage; less often in shrubs or on ground. Usually in small flocks of loose formation, or in pairs.

The California Evening Grosbeak is so irregular as to its seasonal behavior in the Yosemite region that no prediction can be made concerning its occurrence in any stated locality at any given time of the year. In 1915, when field work was diligently prosecuted by our party in the mountains from June until November, the species came to attention only four times; while during a two weeks' visit to the Yosemite Valley and its environs in May, 1919, the birds proved relatively common. Generally speaking, this grosbeak does not appear to be really common anywhere in the Sierra Nevada.

Early on the morning of June 15, 1915, at Crane Flat, two large mustard colored finches having short black tails and showing much white on their wings were seen to fly into a willow thicket in a meadow. These birds proved to be evening grosbeaks. They flitted about the thicket, evidently foraging, and by their close association with one another were believed to be a pair that was established for nesting in the vicinity. Near Mono Meadow on June 16, at Chinquapin on June 18, and near Yosemite Point on October 30, the same year, birds of this species were observed, three being the most seen at any one time.

In 1919 our first contact with evening grosbeaks came early on the morning of May 14 when several were seen feeding in the chaff at the side of an old barn at Hazel Green. Others were seen later the same day at the same place, and on subsequent days, in Yosemite Valley, at Chinquapin, and at Tamarack Flat. In Yosemite Valley 6 were seen together on May 16, and at Artist Point a flock of 8 or more was observed on May 19.

The California Evening Grosbeak is a finch of very distinctive features, not therefore likely to be confused with any other bird. It has a relatively huge conical bill (fig. 52b) of greenish yellow color, a big head set rather close onto the stout body, and a short tail, indented at the end. The bird is somewhat more chunky in build than the commoner black-headed grosbeak; and in similar way it differs from the pine grosbeak still more emphatically. The outstanding color features of the evening grosbeak are the dark body plumage, and the black wings and tail. In the male there are large markings of solid white on the wings, while the female has many small spots of white on both tail and wings. Often when the birds are feeding in the tops of the trees and are seen against the bright sky no color markings can be distinguished; but then the short thick silhouette is entirely diagnostic.

The vocabulary of the evening grosbeak is not elaborate. The bird has none of the extreme loquacity or versatility of expression of the black-headed grosbeak. The only note to be heard commonly is a high pitched two-syllabled call, variously written by us as plee-ek, quer-up, or killip. This is repeated at regular intervals, and is often the first clue to an acquaintance with the species. The song of the male is scarcely more than a succession of these call notes. On one occasion it was written zer-r-p, zir-r-p, prilip. The first two notes of this song were uttered slowly and with a resonant twang, whereas the last note was more high pitched, and uttered with a querulous intonation; the two syllables of it were run together as fast or faster than a person could have pronounced them, forming a sort of trill. The song of another male bird was written prisr-r, präs-r-r, prezer-r; the three notes being given in three different pitches, and, as before, having a curious twanging timbre.

California Evening Grosbeaks do some of their foraging in the crown foliage of deciduous trees and some of it on the ground. Occasionally they visit fruiting bushes of the cascara or some other berry-producing plant. In Yosemite Valley, in May, 1919, some of the birds watched seemed to be eating the tender, newly unfolded leaves of the black oak, while others gleaned forage from the carpet of pine needles and oak leaves on the forest floor. When on the ground the birds progress rather slowly; they turn their heads first to one side and then the other, just as when they are feeding in the trees.

A suggestion as to the courting behavior of the California Evening Grosbeak was obtained in Yosemite Valley near Stoneman Bridge on the afternoon of May 16, 1919. Three males and three females, closely associated in pairs, were actively engaged in foraging on the ground under some black oaks. While the rest of the flock was busily hunting for food, one of the males was seen to spread his wings slightly and droop them so that their tips nearly touched the ground. Then his tail, ordinarily held in line with the back, was cocked up at an angle. The partially opened wings were quivered for a few seconds and then held quiet for a time. No notes were uttered during this display. When this male began his movements another of the male birds quitted his own mate and moved toward the performer; but no real belligerency was manifested.

In the fall and winter months the evening grosbeaks sometimes assemble in flocks numbering many individuals and these bands may stray down into the foothill country. Flocks were noted in Yosemite Valley in September, 1920, and one large flock was seen there October 2, 1920 (C. W. Michael, MS). Large flocks were reported by Mr. Donald D. McLean from Smith Creek, east of Coulterville, in October, 1916. Specimens were obtained at that place on October 11 and December 18 of that year. During the summer season the grosbeaks are sometimes seen in small bands of a dozen individuals or less. It may be that even during the nesting season the adults assemble in flocks for feeding. The flock formation is always loose and the flight of the individuals is strongly undulating, each rising and falling quite independently of its companions. Indeed the band seen at Artist Point looked like nothing so much as 'giant' goldfinches, both their coloration and manner of flight contributing to this impression.

We obtained only one hint relative to the nesting of the evening grosbeak. At Hazel Green, on May 14, 1919, a female was seen flying through the scattering trees of a meadow, carrying a long twig in her bill. She was about 25 feet above the ground, and was followed by a male. Both were soon lost to sight as they made off into the forest of firs.