Caption Group

Fig. 3. Comparison of the extent of moult into non-breeding plumage in American Black Tern and Euro-pean Black Tern. Photos of 166 moulting European birds and 196 moulting American birds were divided into four categories based on extent of moult (see text). The graph shows that American Black Terns in my sample more frequently showed a similar extent of moult across the head and body than other patterns, but this pattern was the least common in European Black Terns. Top row, l–r: Frantz Delcroix, Pavel Štěpánek, Christoph Moning, David Lindo. Bottom row, l–r: Brian Davis, Jay McGowan, Rick Bowers, Brian Sullivan.

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