Two upcoming events

On Thursday, 27 Sep 2007, I’ll be in New Haven, Connecticut lecturing at Yale’s Peabody Museum (where I spent many afternoons as a teenager in the 1970s) as part of their John H. Ostrom program series. Details here (click on September and scroll down) On 19-21 Oct 2007 I travel to Oklahoma to speak and …

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Rare bird news

An eventful few weeks for bird records in North America: The long-anticipated first nesting record of Lesser Black-backed Gull in North America (even though it hybridized with a Herring Gull) – on Appledore Island, Maine. Green Violetear reaches Maine – the farthest northeast record to date. 19 Aug 2007 on Mount Desert Island; photo here …

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Judging size of birds

Size judgment is one of the constant quandaries of bird identification – critically important but fraught with error. In a recent online discussion about these photos of sandpipers in flight, I was intrigued by the question of how I, and others, “just knew” that these birds were too small to be Knot or Pectoral and …

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Olive-sided Flycatcher – white patches and age in fall

Several recent Massachusetts reports of Olive-sided Flycatchers seem to have used the presence of white patches on the sides of the back to age the birds as juveniles. This is incorrect and unfortunately the source of the error seems to be an ambiguous entry in the Sibley Guide – sorry. Both adults and juveniles can …

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Distinguishing Island and Western Scrub-Jays

Feb. 10, 2005 In late October 2004 I was privileged to visit the Nature Conservancy’s spectacular Santa Cruz Island preserve off the coast of Southern California. This island, along with the other California Channel Islands has been called the “Galapagos of the North” and has long been the focus of biological studies, but became more …

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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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