Gen. Char. Similar in general character to M. empidonax, but with fulvous, fulvous-olive and rufous tints, instead of clear olive, gray, white, and sulphur-yellow. Head crested; bristles of gape reaching nearly to tip of bill. Feet very weak.
The type of this genus (M. phæocercus) is quite different in form from Empidonax, the nearest North American ally, but both M. pallescens and fulvifrons could with little violence be placed in it. There is no positive character to separate the latter from the average of species of Empidonax, except it be the color. The crest is not at all conspicuous, nor is there any appreciable difference of form; while in the form of the bill these species are much nearer Empidonax than Mitrephorus. The legs, however, are weaker, and the rictal bristles longer.
There are two forms of the group, as defined by Sclater: one embracing E. phæocercus, Sclater (Mexico and Guatemala), and E. aurantiiventris, Lawr. (Costa Rica); the other E. fulvifrons, Giraud, and pallescens, Coues. The differences between the last two, which are probably merely races of one species, may be expressed as follows:—
M. fulvifrons. Olivaceous above; beneath ochraceous-fulvous; darkest on the breast, paler on throat and crissum. External edge of outer tail-feathers whitish.
Olive of back fulvous; under parts decided ochrey-fulvous. Wing-bands tinged with ochraceous; wing rather pointed. First quill equal to sixth; third, longest. Wing, 2.65; tail, 2.40; tarsus, .61. Hab. Northern Mexico … var. fulvifrons.[97]
Olive of back grayish; beneath obscurely ochrey-fulvous and much paler; wing-bands grayish-white; wing rather rounded. First quill shorter than sixth; fourth longest. Length, 4.75; wing, 2.15; tail, 2.00; tarsus, .55. Hab. Arizona … var. pallescens.
Mitrephorus fulvifrons, var. pallescens, Coues.
BUFF-BREASTED LEAST FLYCATCHER.
Mitrephorus pallescens, Coues, Pr. Philad. Ac. 1866, 63 (Fort Whipple, Arizona).—Cooper, Orn. Calif. I, 334. Mitrephorus fulvifrons, Elliot, Illust. B. Am. I, pl. xix.
Sp. Char. Above fulvous-gray, with an ashy cast on the tail and crown; lighter across the nape. Two grayish-white bands across the wings, and the terminal half of the secondaries and outer web of lateral tail-feather broadly edged with the same. Whole lower parts, including the lores and cheeks, and lining of wing, light ochraceous, very deeply ochraceous across the breast and on the sides, nearly white on the abdomen and crissum. Upper mandible deep black, lower whitish (“bright orange-yellow” in life); feet deep black. Wing-formula: second, third, and fourth quills equal and longest, 5, 6, 1. Tail very slightly emarginated, but lateral feather a little the shortest. Male. Length, 4.75; wing, 2.25; tail, 2.00; culmen, .54 (measured to concealed base); breadth of bill, .24; tarsus, .54; middle toe, .28. Female. Colors paler; deep ochraceous of breast, etc., less distinct.