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David Sibley

Distinguishing South Polar Skua and Pomarine Jaeger

December 11, 2004 I was intrigued by this problem in light of the discussion surrounding the recent (6 November 2004) bird from southern Texas (see photos here and here; and sincere thanks to Martin and Chris for making these photos available and thanks to all who have participated in the discussion and our collective education). We wouldn’t

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Identification of the Martha’s Vineyard Red-footed Falcon

Illustration of the Red-footed Falcon perched. The smooth gray color is unlike any North American Falcon. Old juvenal wing and tail feathers are slightly brownish and barred, while adult feathers will be uniform blackish. Juvenal feathers are obvious on the outer tail, the primaries (molt reveals the boldly barred inner web of one outer primary),

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Distinguishing Trumpeter and Tundra Swans

The separation of Trumpeter and Tundra Swans has been a perennial challenge. Both are obviously swans, and given decent looks they are easy to distinguish from Mute Swan, but criteria for separating Tundra Swan from Trumpeter Swan are subjective and often vague, requiring experience and/or direct comparison. Until recently there were relatively few places where

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Updates and Corrections for the Sibley Western Guide

p 143 – Pacific Golden-Plover: on adult male breeding the labels pointing to undertail coverts and flanks are reversed. p. 252 – White-throated Swift: name is incorrect, Whited-throated Swift p. 279 – Greater Pewee: map is a duplicate of Buff-breasted Flycatcher map. The summer range of this species should extend slightly farther north in Arizona,

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Prints for sale

Black-and-white prints from “The Wind Masters” Osprey print is sold out. This set of four prints is taken from artwork originally published in The Wind Masters by Pete Dunne (Houghton Mifflin Co., 1995). The original drawings were done in 1993 and 1994 on scratchboard, a medium in which ink is applied to a board and

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What species are in the Eastern and Western bird guides?

The Eastern and Western Guides were carefully planned to avoid dividing states. The Rocky Mountains form a natural biological and climatic division of the continent, and basically any state or Province entirely east of the Rocky Mountains will be covered by the Eastern Guide, while states and provinces in, or west of, the Rockies will

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