Birder's Guide

OCT 2014

Birder's Guide is the American Birding Association's newest publication. Each issue focuses on a key subject, providing tips from experienced birders on a wide variety of topics like Travel, Listing & Taxonomy, Gear, and Conservation & Community.

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40 Birder's Guide to Listing & Taxonomy | October 2014 Check-list Supplement Redux, v. 2014 case here, and confusion may result. These three species are almost identi- cal in appearance, but differ markedly in voice. That makes it nearly impos- sible—for now—to identify sight records of silent migrants. And most migrants are unfortunately silent. It is thus unknown which species are represented by many records of migrant birds on Alaskan is- lands and in western Canada, the Lower 48, and Mexico. Now, what to call these unidentifed birds? We can't call them Arctic Warblers, because no one will know whether we mean the "new" more-restric- tive species or the "old" more-inclusive one. I suppose we will have to settle for "old Arctic Warbler". "Arctic Warbler sensu lato" or "Arctic/Japanese Leaf/Kamchatka Leaf warbler"—have fun calling that last one out in the feld! If you've seen an Arctic Warbler in Denali National Park, then you've still seen an Arctic Warbler. The "new" Arctic Warbler is the species that breeds in Alaska, all the way west to Scandinavia. It migrates to southern and eastern Asia for the winter. The AOU supplement lists four records of the "new" Arctic Warbler for California; it also states that Kamchatka Leaf Warbler is casual in the Aleutians (Howell et al. men- tion 19+ on Attu in one day) and that two records of "Arctic Warbler" from the Northwest Territories are not conclusively identifed to species. It has been speculated that a re- cord from Baja California involves Kamchatka Leaf Warbler. Japanese Leaf Warbler has no confrmed records and is not placed on the Check-list. Note that the sixth edition of the National Geographic Field Guide to the Birds of North America mentions and illustrates xanthodryas, but the authors are really referring to what we today call examinandus. Kamchatka Leaf Warbler (examinandus) and Japanese Leaf Warbler (xanthodryas) were formerly considered the same subspecies (xantho- dryas) of Arctic Warbler. So Kamchatka Leaf Warbler frst became its own subspe- cies, and now is considered its own spe- cies—quite a step up! For details on differ- ences among the three species, see Howell et al.'s Rare Birds of North America (2014). Also check out , where you can listen to the differ- ent vocalizations. Shy Albatross Split –––––––––––––––––––––––––––––––––– • White-capped Albatross (Thalassarche cauta) • Salvin's Albatross (Thalassarche salvini) • Chatham Albatross* (Thalassarche eremita) All three of the "Shy Albatrosses" nest on islands of the South Pacifc; any appear- ances they make in the ABA Area are as vagrants. Most records pertain to White-capped Albatross, of which there are a handful of records off the Pacifc Coast of the Lower 48. From below, the basal half of its pri- maries are white. Adults have pale gray necks and cheeks with contrasting white caps and napes. Their bills are pale gray- green with a yellow tip. There are two subspecies. Adult "Tasmanian Albatrosses" (cauta) have a yellow ridge along the base of the culmen; they breed off Tasmania. Adult "Aukland Albatrosses" (steadi) have this area gray-green, like most of the rest of Arctic Warbler on territory in Denali National Park in Alaska. Photo © Robert Royse Note the mostly pale head, extensive pale bases to the pri- maries, and the dull bill on this adult White-capped Albatross near New Zealand's Stewart Island. Photo © Jon Irvine Note the gray hood, extensive dark in the primaries, and relatively dull bill on this adult Salvin's Albatross near New Zealand's Stewart Island. Photo © Jon Irvine Note the very dark hood, extensive dark in the primaries, and bright orangish bill on this adult Chatham Albatross near New Zealand's Stewart Island. Photo © Jon Irvine Kamchatka Leaf Warber at Paratunka on Russia's Kamchatka Peninsula. Photo © Anders Blomdahl

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