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.

Issue link: http://nab.aba.org/i/629070

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15 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 for retained fight feathers during the prefor- mative molt, similar to retention patterns of some migratory North American passerines (e.g., Empidonax and Myiarchus fycatchers) in which eccentric molts can occur in longer-dis - tant migrants (Pyle 1997, 1998). These shrikes differ from species showing eccentric molts in that fewer juvenile primaries and primary coverts are retained due to bidirectional rather than the unidirectional (distal) replacement within this tract found in most birds. Adult cristatus Brown Shrikes have been reported to undergo two complete molts per year (Medway 1970, Stresemann and Stre - semann 1971, Svensson 1992, Cramp and Perrins 1993, Jenni and Winkler 1994), but confrmation of this is lacking due to an in - ability to trace feather replacement in wild in- dividuals throughout a molt cycle in a natural setting. It is possible that this interpretation was based on separate individuals undergoing the complete molt at variable times of year; for example, some individuals may molt fight feathers in August–November, others in Janu - ary–March, and some may molt throughout this period with one or more molt suspen - sions, while few or no individuals molt fight feathers twice within a cycle. Specimens exam - ined for this paper, collected in both late sum- 9c 9d 9e

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