BLACK-CHINNED HUMMINGBIRD Archilochus alexandri (Bourcier and Mulsant)

Field characters.—Male with chin non-iridescent black, bordered immediately below by a narrow iridescent purplish collar; back and top of head dark iridescent green; flanks greenish. (See pl. 46c). Female with top of head and back bronzy green; under surface grayish, with faint buffy tinge on flanks; no rufous or greenish tinge on sides; ends of outer tail feathers wedge-shaped.

Occurrence.—Summer visitant locally at lower altitudes on both sides of the Sierra Nevada. Recorded at Snelling, Dudley (6 miles east of Coulterville), El Portal, and Mono Lake Post Office.

The Black-chinned Hummingbird is a foothill species, found in the summertime along the beds of cañons and adjacent lower slopes. A male was seen at Snelling on May 28, 1915, perched on a dead willow stub in the tangled river-bottom vegetation; and on May 2, 1916, another was seen in growths of yerba santa on the hillside above El Portal. At Mono Lake Post Office a male was seen feeding at the blossoms of a wild currant, during a snowstorm on May 23, 1916, seemingly unmindful of the state of the weather. Three days later another was seen sitting on a barbed wire fence. Later in the season (June 30), at the same place, four were seen, one of which was driving a Green-backed Goldfinch away from the hummer's favorite perch on a willow twig near an irrigating ditch.

At Dudley, on Smith Creek, 6 miles east of Coulterville, according to Mr. Donald D. McLean, this hummingbird does not arrive until the middle of June. Nesting there takes place, therefore, rather late in the season. Three nests have been found, all on the ranch, close to the house. On July 14, 1920, a nest containing 2 fresh eggs, which the female was beginning to incubate, was found situated 4-1/2 feet above the ground on a slender drooping limb of an apple tree. The nest was saddled in a little crotch where a fine twig was given off. It was but an inch in height by 1-3/8 inches in diameter. The materials comprising it included tufts of grayish plant down, and bud scales and seed pods, the whole bound together and to the support with spider web.

Full-grown young-of-the-year were collected at this place July 26 and August 9, 1920.

A 'poker plant' in the ranch garden was the common rendezvous of all the hummingbirds in the vicinity, and here the female of the nest just described and a male Black-chin not infrequently foraged together amicably. But the male was forcibly repelled by the female whenever he attempted to approach the precincts of the nest. Mr. McLean states that earlier in the season at lower altitudes, especially around Coulterville, the species nests more commonly.