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May 2001
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| The taxonomic status of Green-winged Teal Anas carolinensis George Sangster, Martin Collinson, Andreas.J. Helbig, Alan G. Knox , David T. Parkin and Tony Prater |
During the second half of the twentieth century, Green-winged Teal Anas carolinensis was almost universally treated as a subspecies of 'Common Teal'. Reassessment of morphological and behavioural differences between Green-winged Teal and Eurasian Teal A. crecca, together with molecular evidence regarding the phylogenetic relationships of Green-winged Teal, Eurasian Teal and Speckled Teal A. flavirostris, indicates that these taxa are best treated as separate species. The status of Green-winged Teal as a species can be justified under the Phylogenetic, Evolutionary and Biological Species Concepts.The basis for recognising A. c. nimia as a separate taxon is weak, but merits further study.
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| From the Rarities Committee's files Blyth's Reed Warbler: problems and pitfalls Colin Bradshaw on behalf of BBRC |
Blyth's Reed Warbler Acrocephalus d metorum remains one of the most difficult identification challenges facing field birders in Britain. This paper describes a case where identification was still not proven, despite the bird being trapped and measured.This example raises a num er of important general points regarding the process by which rarities are assessed, in particular the care with which photographic evidence and biometric measurements must be interpreted.
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