North American Birds

VOLUME 69 No1 2016

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.

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T H E M E N D O C I N O S H R I K E 8 N O R T H A M E R I C A N B I R D S a general consensus had formed that the bird was either a hybrid involving Red-backed Shrike, or a Brown Shrike of subspecies L. c. lucionensis, or (perhaps) L. c. confusus, thought by some to represent an intergrade between lu - cionensis and nominate cristatus. As a small Lanius shrike showing various grayish, rufous, and brownish tones dorsally, having a distinct dark mask, and being white below with a wash of coloration to the sides, the Mendocino shrike ft well in the assem - blage that includes Red-backed, Turkestan, Isabelline, and Brown Shrikes. When the bird was frst observed, its crown was dull gray and brown, the back dull rufous-brown, the rump and uppertail coverts a brighter cinnamon to pinkish rufous, and the underparts white with a dull pinkish-buff wash on the sides. As the bird molted, the crown became a brighter silvery gray mixed with some rufous-brown in the nape, the upper back became brighter rufous-brown, the lower back and rump be - came grayish, and the sides were washed with a brighter apricot-orange tone. The older wing and tail feathers were brownish to cinnamon in coloration, while the replaced remiges were 3a 3b 3c Figure 3. The underparts of the Mendocino shrike during diferent dates and showing the efects of body molt on the coloration to the sides and fanks: 13 March (a), 21 March (b), 27 March (c), 30 March (d), 4 April (e), and 17 April (f ). Careful readings of feld descriptions, and direct personal observations, indicate that these images more or less cap - ture the true coloration of the underparts as it changed over the period of observation. Photographs by Steve Stump (a), Thomas Benson (b), John Sterling (c), Monte Taylor (d), Gary Woods (e), and Patricia Bachetti (f ). duskier brown and the replaced rectrices were variously mixed dark rufous-brown and black - ish from above and pale grayish basally with indistinct dusky tips from below. The inner web of at least one new rectrix appeared to have a whitish patch at its base, and the newer replaced outer primaries had white bases that extended beyond the primary coverts. A more exhaustive description of individual feathers and feather tracts, within the context of molt progression, is given below. Overview Red-backed, Turkestan, Isabelline, and Brown Shrikes form a species assemblage, with as few as one and as many as seven taxa considered distinct species during the course of a check - ered taxonomic history (Dement'ev and Glad- kov 1954, Vaurie 1959, Pearson 1979, Cramp and Perrins 1993, Kryukov 1995, Worfolk 2000, Panov 2009, Panov et al. 2011, Pearson et al. 2012). Variation in plumage and struc - ture, even among adult males, hybridism and/ or character introgression, poorly documented breeding and non-breeding distributions in some cases, and a diffculty in identifying fe - male and frst-cycle birds have all contributed to this taxonomic uncertainty. In discussing the identifcation of the Mendocino shrike, we follow Panov et al. (2011), Dickinson and Christidis (2014), and Gill and Donsker

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