Birdwatch News Archive

Only the nominate form of Arctic Warbler, like this bird at Spurn, East Yorkshire, in August 2003, is likely to have occurred in Britain. Photo: Steve Young (www.birdsonfilm.com).

Changes to the British list

Posted on: 19 Sep 2012

Several long-awaited decisions have been announced by the Taxonomic Subcommittee of the British Ornithologists' Union's Records Committee, but there are also some surprises in a move which will have a significant impact on the BOU’s British list.

Most predictable for many birders are the acceptance of three-way splits in the species formerly known as Cory's Shearwater and Madeiran Storm-petrel, while Arctic Warbler, Marmora’s Warbler and Nuthatch are also split. In more detail, the key changes affecting species in Britain and Europe are as follows:

Scopoli's and Cape Verde Shearwaters are split from nominate Cory’s on the basis of differences in vocalisations and biometrics, as well as there being only one record of a hybrid between Scopoli's and Cory's (despite the existence of mixed colonies), implying reproductive isolation between each form. Cape Verde Shearwater is restricted to its nominal island group. Cory's and Scopoli's are both already on the British List, the latter as a vagrant with just one record from Scillonian waters.

Madeiran Storm-petrel is also split into three: Madeiran breeds on Madeira and the Selvagens, Cape Verde Storm-petrel is endemic to that island group, and Monteiro's Storm-petrel breeds in the 'hot season' on the Azores. A fourth form, tentatively dubbed 'Grant's Storm-petrel', is retained within Madeiran at present, and breeds in the 'cool season' on the Azores, Madeira, the Selvagens and a few Portuguese offshore islands. The recently accepted first Madeiran Storm-petrel record, from Scilly, should now be reassessed to see what taxon was involved – a potentially imposible task given the difficulty of field identification.

Another predicted split (see www.birdwatch.co.uk/categories/articleitem.asp?item=741) is Arctic Warbler, which becomes Arctic, Kamchatka and Japanese Leaf Warblers. As far as is known, only nominate Arctic has occurred in Britain, and indeed Europe.

Birders who follow BOU taxonomy and who have visited the Balearic Islands will pleased to know that their ‘insurance tick’ of Balearic Warbler as a split from Marmora's has finally been accepted by the committee. The BOURC is now to review the six records, though it seems likely all will involve the more migratory Marmora’s.

A rumoured but less anticipated split involves Nuthatch, in which the form arctica becomes a full species, Siberian Nuthatch. It is reported to have occurred at least once in northern Europe.

In addition, there has also been some restructuring of the Galliformes (gamebirds) and Charadriiformes (gulls, terns and waders). Perhaps the most notable change has been the inclusion of Surfbird, Ruff, Broad-billed, Spoon-billed and Buff-breasted Sandpipers within the genus Calidris; all previously possessed their own monotypic genera.

To read the full paper, click here.