North American Birds

VOLUME 70 NO3-NO4 2019

A Quarterly Journal of Ornithological Record Published by the American Birding Association. The mission of the journal is to provide a complete overview of the changing panorama of our continent’s birdlife.

Issue link: http://nab.aba.org/i/1115839

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RED-BACKED SHRIKE IN ALASKA 254 N O R T H A M E R I C A N B I R D S peared to include the lores, but at other times the lores appeared mostly pale, though with some darkening toward the bill base. Many of the scapulars and lesser and me- dian wing-coverts showed thin pale tips and dull, dark subterminal bars or crescents. The tertials, secondaries, and greater coverts were dark-brown or perhaps blackish-brown centered with broad warm-buff fringes and whitish tips. The primaries and primary co- verts were blackish with distinct, sharp, pale tips to each of the visible feathers. The underparts were off-white, with a faint buff wash visible ventrally and on the flanks, perhaps more obvious in shade or overcast conditions than in bright light (fig 1). The bird lacked any other buff, ochre, or darkish tones below and, depending on the view or photo, showed thin dark barring, crescents, or vermiculations—varying in boldness— from the lowermost auriculars down the en - tire sides of the breast through to the lower flanks. The pale-buffy undertail coverts were unmarked (fig 7D). The underside of the tail was mostly a dull brown or grayish-brown. • WING AND TAIL MORPHOLOGY: The primary projection was long, with photos showing six to eight exposed primary tips ness varied with the views and from photo to photo, they were always clearly present if the bird was seen well. The nape region was contrastingly grayer, and without vermicula- tions (fig 1, 4, and 6). This grayer, plainer nape was a characteristic noticed often in the field, though its boldness varied somewhat with the angle, lighting, and pose. The rump and uppertail coverts showed some limited, incomplete dark barring or vermiculations (fig 3), mostly toward the sides. The upper surface of the tail was largely plain, and in addition to the darker central rectrices noted above, it also showed a distinct, thin, whitish outer edge to the outer rectrices, and a less distinct, not always apparent, pale tip to the entire tail (fig 3 and 6). There was a fairly distinct pale supercilium present, but it was often visible only behind the eye, although in some photos it shows weakly in front of the eye as well. The eye appeared dark brownish. The dark mask through and behind the eye was a warm, me - dium-brown color, in some lights showing strong rust tones (especially to the rear), not dark brown or blackish, and thus of relatively low contrast. The exact color and boldness varied depending on the angle and lighting— in some views, the darkness of the mask ap - than in most Brown Shrikes, having a nar- rower base and with the lower mandible appearing straight rather than convex, and showing an extensive dull yellowish or pink - ish color to the base of both mandibles. The legs were pale gray. • PLUMAGE: The Gambell shrike was pri- marily in juvenile plumage (see below). As shown in fig 1-6, the crown, mantle, and rump were a warm, rusty brown. The up- per surface of the tail was also largely warm brown, but the central rectrices appeared a darker and cooler brown (fig 3 and 6). The crown and back showed patches of thin, dark, mostly crescent-shaped vermiculations (fig 1, 3, 4, and 6). Although their distinctive- Figure 3. In this photo of the Gambell shrike, taken 10 Oct 2017, note the darker central rectrices, a feature that fa- vors Red-backed over Brown shrike. Note also the brighter and unbarred rufous crown feathers, scapulars, and lesser coverts, signs that the preformative molt of body feathers had commenced. Otherwise, the extensively bared upper- and underpart feathers and patterned and pale-fringed wing coverts are juvenile and, along with the pale yellow- ish base to the bill, indicate a first-fall bird. Note also the blackish flecks in the auriculars, along with darker remiges and brighter and unbarred replaced upperpart feathers, possibly indicating a male. Photo by © Sue Bryer

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