To refer to this article use this url: http://www.zoologischemededelingen.nl/80/nr05/a16
Acknowledgements
Thanks are due first to Alexander Nazarenko and Yaroslav Red’kin for the two papers that have been prepared in parallel to this. Robert Prys-Jones and Mark Adams kindly facilitated the examination of specimens at The Natural History Museum, Tring, where Alison Harding was, as usual, most helpful with the library research. Ann Datta helped with the date for the citation to Gould’s The Birds of Europe. Norbert Bahr kindly obtained a copy of Löhrl & Thielcke (1969) and translated the relevant text for me. For discussions about S. n. grisiventris I am grateful to Till Töpfer who looked at specimens with me, and for discussions about relevant molecular studies by others, now in course of planning, thanks go to Jochen Martens and Eric Pasquet.