| OCR Text |
Show 112 white or pale rusty ground. Wing, 6.35- 6.95; tail, 5.50- 6.30; culmeu, 0.35- 0.40; tarsus, 1.85- 2.05; middle toe, 1.05- 1.25. Young female :*- Exactly like the vouug male iu markings and colors. Wing, 7.75- 8.60; tail, 6.50- 7.60; ail men, 0.45- 0.50 ; tarsus, 2.05- 2.3U; middle toe, 1.30- 1.50. To represent the average style of the adult male, we select a specimen from Pennsylvania, No. 50055, Nazareth ; L. E. Liicksecker. In this example, the upper parts are a uuiform plumbeous throughout, the pileum being hardly appreciably darker than the back, and the tail equally blue with other portious; the tail has a distinct, narrow, white, terminal border; the longer upper tail- coverts also have very narrow white tips. On the lower parts ( i. « ., breast, sides, flanks, and abdomen), the white and rufous bars are about equal iu width, the latter growiug wider toward the shaft of the feathers, along which they are connected by a narrow streak of rufous, the shaft itself being blackish ; the white bars being thus brokeu into transverse oblong spots. There are now before us thirty examples of the adult of this species, and we have examined many more; and our conclusion is that the variations exhibited in the plumage are purely individual, haviug nothing to do with climatic causes, since the two darkest examples are from Chiriqni, New Granada, and Fort Bridger, Wyoming, and the two lig! it-est colored ones are from Guatemala and Fort Resolution, Hudson's Bay Territory, while others from the Atlantic States are not distinguishable from some obtained on the Pacitie coast. As illustrating the extremes of variation in the adult plumage, we cite the following specimens:- The lightest in the entire series is an adult male from Choctun, Vera Paz, Guatemala ( January), in the collection of Mr. Salvin. In this, the upper parts are a light, decidedly bluish, plumbeous, with conspicuous black shaft- streaks, exceedingly similar to the dorsal surface of adult males of Falco columbarim; the pileum is decidedly darker, with the shaft- streaks less conspicuous, and the tail is decidedly more browuish than the upper coverts. There is a quite distinct narrow superciliary stripe of small white streaks. The general aspect of the lower parts is white, all the feathers except on the anal region and crissum with very conspicuous blackish shaft- streaks, these being rendered the more prominent by the faiutness of the rufous markings, which are distinct only along the sides, and even on the tibse are narrower than the white interspaces. A peculiar feature of this specimeu, so far as the series before us is concerned, is that the dusky bands on the inner web of the primaries are broken into irregular cloudings, although they have a general tendency toward transverse bands. A specimen from Fort Resolution, Hudson's Bay Territory, April 30 ( No. 629, Mus. It. R), is very similar, but the bars of the fower parts are better defined, although not deeper in color, and the upper parts are darker and more uniform plumbeous ; the superciliary streaks are also concealed or nearly obsolete. In this specimen, as iu many others, the rufous bars are bordered with a uarrow, dark, slaty margin. The darkest examples are an adult male in Mr. Salvin's collection ( No. 3705) from the southern slope of the volcano of Chiriqui; one from Utah ( Beaver, September, 24; No. 2130, Mus. B. K.); and one in the National Museum, from Fort Bridger, Wyoming ( No. 10759, May 26). The two former are alike in their upper plumage, which is a very dark plumbeous, becoming gradualy but very perceptibly darker on the pileum, the shafts not conspicuously darker; the longer upper * Iris sniphur- yellow ; tarsi aucl toes rich leuiou- yellow. ( Fresh colors of No. 53204.) |
