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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Page 12 of 179

Figure 6. Progression of primary and rectrix molt in the Mendocino shrike on 21 March (a), 27 March (b), and 4 April (c). See text for details. Note also the contrast between cinnamon outer juvenile rectrices and blackish inner formative rectrices on 27 March (b). Photographs by Thomas Benson (a), John Sterling (b), and Larry Sansone (c). 11 V O L U M E 6 9 ( 2 0 1 5 ) • N U M B E R 1 T H E M E N D O C I N O S H R I K E Korea and winters in eastern Southeast Asia and the Philippine Islands through northern Borneo and the Celebes Islands (Figure 4). A third taxon, confusus, is believed to breed in northeastern China, southwestern Siberia, and northeastern Korea; it probably winters primarily in Southeast Asia (Figure 4). Again, our understanding of winter ranges of the Brown Shrike subspecies has been obscured by diffculty in identifying females and frst- cycle birds away from the breeding grounds. Subspecies confusus could intergrade with lucionensis in Korea (Fiebig 1995, in Tomek 2002) and in China and Russia with cristatus. A fourth subspecies of Brown Shrike, super - ciliosus, which breeds in southern Sakhalin Island and Japan and winters in Southeast Asia and Indonesia, shows plumage and structural features not shown by the Men - docino shrike (including an extremely long tail and a bright white forehead and distinct supercilium in males) and is not considered further in this paper. Adult male nominate cristatus Brown Shrikes have uniform crowns, upperparts, and tails that vary from reddish brown to brown, whereas lucionensis shows a grayish crown transitioning to a duller mud-brown back and tail. Underparts of both subspe - cies are variable but are often extensively dark buff and occasionally mixed with dull 6a 6b 6c ochraceous. Subspecies confusus shows the widest range of characters; this and its poor - ly defned distribution suggest that many presumed confusus could be intergrades between other taxa (Worfolk 2000, Moores 2015) or in some cases possibly hybrids be - tween Brown Shrike and Isabelline Shrike, though such hybrids may be rare (Kryu - kov 1995). True to its trinomial, confusus is therefore considered here as a catch-all name given to those Brown Shrikes that show a combination of features suggesting cristatus or lucionensis but that seem to ft neither of these taxa well. Although these four Brown Shrike subspecies vary tremendously in plumage, they share consistent wing and tail morphologies that differ signifcantly from the other shrike species in this assemblage. There are 17 records of Brown Shrike from North America, 12 from Alaska in 1978- 2015 (nine from fall and three from spring), four from California in 1984-2011 (two from fall and two of wintering birds), and one in November 1997 from Nova Scotia (C.B.R.C. 2007, Howell et al. 2014, Gibson and Withrow 2015; D. Gibson, P. Lehman, pers. comm.). Most records have been as - signed to the nominate subspecies, cristatus, with the remainder being frst-cycle birds that were likely cristatus but not confdently determined to subspecies. The frst Alaska record was tentatively identifed as lucio - nensis (Gibson 1981) but has subsequently been identifed as nominate cristatus (Gib - son and Withrow 2015). Hybridization between Red-backed and these other three migratory shrike spe - cies has been documented on the breed- ing grounds (Dement'ev and Glakov 1954, Kryukov and Panov 1980, Andrusenko and Panov 1993, Kryukov 1995, Kryukov and Gureev 1997, Worfolk 2000, Panov 2009, Panov et al. 2011), from Iran to Kazakhstan with Turkestan Shrike and in the Altai region of south-central Russia with all three other species (Figure 4). In - dividuals thought to be hybrids with Red- backed Shrike have also been recorded on migration or winter grounds, in eastern Africa (Pearson 1979), most countries of the Middle East, including Saudi Arabia (Babbington 2013, 2014), Malaysia (Mun 2015), and Japan (Horimoto and Watabe 2014, Young Guns 2014). Hybridization between Red-backed and Turkestan Shrikes is extensive if not indiscriminate, within a fairly expansive but poorly delineated zone extending from the Caspian Sea to the Altai region (Figure 4). Panov et al. (2011: 475- 480, 568-591) speculate that Red-backed and Turkestan Shrikes may be one biologi - cal species, and that the two duller eastern p4-p5 new, p3 and p6 growing, p2 dropped p2 dropped and p6 growing, p4-p5 new, p3 r1-r2 growing r1-r2 growing r6 remaining remaining r6 p8-p10 juvenile juvenile p8-p10 p6-p7 growing p6-p7 growing p4-p5 50% grown p3 25% grown p4-p5 50% grown g r o w n o w p3 25% grown p 3

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