7 September 2015

Changes to the British List

The British Ornithologists’ Union Records Committee (BOURC) has accepted the following subspecies on to the British List:

‘Thayer’s Gull’ Larus glaucoides thayeri
Adult, Pitsea Landfill Site, Essex, 6 November 2010 (photographed).

A series of excellent photographs allowed the identification of this individual to be established.

Breeds in northern Canada, wintering on the west coast of North America.

‘Daurian Shrike’ Lanius isabellinus isabellinus
A record of an adult on Fetlar, Shetland, 14-17 September 2002 (photographed).

Though the species Isabelline Shrike Lanius isabellinus is currently in Category A, a record to establish the nominate subspecies isabellinus was required. A number of candidates were considered with this individual most robustly fulfilling identification criteria.

Breeds in central and eastern Asia, wintering in the Middle East, North-east Africa and the Indian subcontinent.

Other decisions

Marbled Duck Marmaronetta angustirostris
A review of the categorization (currently Category D) of this species has been completed, and due to the ongoing high possibility of escape, the species has been moved to Category E.

The Committee encourages submissions of records of this species in the future, particularly of records where a ringing recovery or stable isotope analysis could establish wild origin.

Further details will be published as part of the BOURC’s 45th report due to be published in the January 2016 issue of IBIS.

Upon publication of these decisions in IBIS, the British List will remain at 598 species (Category A = 580; Category B = 8; Category C = 10).