WILLOW GOLDFINCH. Astragalinus tristis salicamans (Grinnell)

Field characters—About half size of Junco. Sexes different in summer, nearly alike in winter. Male in summer brilliant canary yellow, with wings and tail black and cap black; edgings of wing feathers white, and white showing in mass at end of tail (fig. 53a). Female dull greenish brown, with white markings of male obscurely represented. In winter both sexes brown above and light grayish brown beneath; wings and tail as in summer, but light edgings on wings more conspicuous. Flight markedly undulating and buoyant. Voice: Male in summer has a spirited and varied song; a characteristic series of notes is given during flight, and there are simple call notes.

Occurrence.—Common resident of the lowlands (Lower Sonoran Zone), less numerous in foothills (Upper Sonoran Zone), on west side of Sierra Nevada. Observed at Snelling, near Lagrange, and at Pleasant Valley, and reported from Yosemite Valley. Shows marked preference for vicinity of willows. Usually in flocks of varying size.

The Willow Goldfinch is the most brightly garbed of our three species of 'wild canaries,' the body plumage of the male during the spring and summer season being clear yellow, set off by black on the head, wings, and tail. As both its English and Latin names indicate, this bird is a frequenter of willow growths and is to be looked for accordingly in the neighborhood of water. In the Yosemite region, however, it is restricted to the lowlands, and we did not find it in the willows which line the rivers and creeks at the higher altitudes.

We found Willow Goldfinches in numbers only at Snelling and below Lagrange; in other words, in the Lower Sonoran Zone. At the former place in January, 1915, from 6 to 8 could be recorded in a half-day census; by May of the same year they were much more in evidence, as many as 40 being recorded on the morning of May 26, 1915. Then they were flying about continually, in pairs or little companies, and some were foraging with linnets in patches of star thistle. As late as October 22, 1915, they were abundant, 32 being seen in 13 minutes from the window of a train going from Snelling to Merced Falls. A single bird was collected at Pleasant Valley on December 1, 1915. We saw nothing of the species at any of our other camps in the foothills, but Mr. Donald D. McLean tells us that the Willow Goldfinch occurs regularly at his home 6 miles east of Coulterville. Mr. Otto Widmann (1904, p; 69) saw this goldfinch in Yosemite Valley once, on May 21, 1903, and Mr. Joseph Mailliard (1918, p. 16) reported it there on August 19, 1917. The species was not seen at all by us east of the Sierras.

The flight of the Willow Goldfinch, and in fact of all of our goldfinches, is markedly undulating in its course and the bird is light in its carriage. The wings do not beat continuously, but after a few strokes there is a slight pause. The beats carry the bird upward and then as the wings remain closed it swings down again. This succession is repeated over and over by each individual so that when a number are flying together in open company, as is their custom, each rises and falls rhythmically but independently of its companions. The relation between the lifting power of the relatively large spread of flight feathers to the total bulk of the body is such that a few rapid strokes of the wings will carry the bird in a buoyant manner quite different from the direct flight of the heavy-bodied, round-winged, brush-inhabiting sparrows.

The Willow Goldfinch molts twice each year, once in the fall when the entire plumage is replaced and again in late winter and spring when only the body feathers are changed. The brilliant yellow garb of summer is exchanged in August or September for a coat of greenish brown, and the black cap of the male is lost. The prenuptial or spring molt is less definite in time of occurrence. Some birds show new yellow feathers as early as January while others still retain some brown winter feathers as late as May.

The nesting activities of this goldfinch do not usually begin until summer is well advanced, that is to say, until July. A female bird was seen at Snelling carrying material for a nest on May 29 (1915), but other birds observed on that date gave no indication of nesting. Our field work at the lower altitudes did not cover the summer months when these birds would ordinarily be expected to be nesting in numbers.