WESTERN MOCKINGBIRD. Mimus polyglottos leucopterus (Vigors)

Field characters.—Length about that of Robin, but build much more slender; tail longer than body and rounded at end. Upper surface plain dark gray, under surface nearly white (spotted in young); wing with a large white patch, and tail margined with white, these areas showing forth best in flight. (See pl. 53a). Voice: Song exceedingly varied; imitates calls of many other birds (whence the name); call note a harsh chuck.

Occurrence.—Sparse resident in Lower Sonoran Zone; found at Snelling, and west of Lagrange and Pleasant Valley; casual visitant (December 12, 1915) at Smith Creek east of Coulterville. Lives usually among scattering small trees. Solitary or in pairs.

Western Mockingbirds are to be found in the orchards at Snelling and Lagrange, and in the scattered blue oaks which intervene between the floor of the San Joaquin Valley and the foothill chaparral belt. The species is by no means so numerous here as in the orange groves of southern California, six individuals being the greatest number seen during any one morning's observations. The open stands of oaks and other small trees seem to offer congenial surroundings to a small resident population.

More than perhaps any other bird is the mockingbird noted for both variety and loquacity of expression. Its voice is to be heard during most of the daylight hours and often from time to time during the night, as also through a large part of the year. In May, October, and January, visits to Snelling found the species in full song. Only during the season of molt, in summer and early fall, is it quiet. At all other times of year this accomplished mimic exercises its art of reproducing, with large measure of success, the calls distinctive of its various feathered associates. Its repertoire includes excerpts or practically complete reproductions from the vocabularies of a large percentage of the birds in the vicinity. One individual listened to at Snelling on January 10, 1915, imitated, with modifications, the California Linnet, the Western Meadowlark, and Shrike; while another near Pleasant Valley, on May 28 that year, mimicked the Crow, California Jay, Plain Titmouse, and Western Gnatcatcher, besides interpolating some of its own characteristic notes.

On a hill slope below Lagrange a Western Mockingbird was watched one evening early in May, 1919. His demesne was a gentle south-facing slope once cleared of its large blue oaks, and since grown up with small ones, hence giving much the impression of a Pasadena citrus orchard; from the top of one of these orange-tree-shaped oaks, just as the sun sank into a bank of haze, the bird was pouring forth his ecstatic song with all the fervor of his relatives in the southland.

Winter here affords the mockingbirds as plentiful forage as the summer season; mistletoe berries then abound. At Snelling in January, 1915, the birds frequented the cottonwoods laden with the fruits of this parasitic plant, and the one bird taken for a specimen had little else in its stomach.