British Birds VOLUME 82 NUMBER 1 1 NOVEMBER 1989 Report on rare birds Sponsored by in Great Britain in 1988 Michael J. Rogers and the Rarities Committee with comments by R. A. Hume his is the thirty-first annual report of the Rarities Committee, and it Tis the seventh consecutive year in which ZEISS West Germany has sponsored the Committee's work. We are extremely appreciative of this support, which enables us to continue to process thoroughly each individual record submitted, to publish this report in such detail and to include within it so many photographs and drawings of rarities. The interest in birdwatching, and in rare birds in particular, is growing annually, and the workload of the Committee is increasing as a result, so this very welcome financial assistance from ZEISS West Germany becomes more important each year. Rarities Committee membership is listed on the inside front cover each month, and on the back of the title page in each volume. Points of interest arising mainly from the Committee's annual meeting in April 1989 have been published already in 'Rarities Committee news and announcements' (Brit. Birds 82: 418-419). Details of the Committee's constitution and operation have been published in 'Rare birds: the work of the British Birds Rarities Committee' (Brit. Birds 80: 487-491) and are contained in a fact sheet, a copy of which may be obtained from the Secretary, Michael J. Rogers, whose address is at the end of this report. Also available from the Secretary is a list of the species considered by the Committee, and copies of the Rarities Committee Record Form, which should be used (or its format followed) when submitting reports. Please enclose a stamped addressed envelope of suitable size when requesting any of these items. All reports of any species on the Committee's list should be sent to the Secretary or, in the case of a trapped and ringed rarity, to the BTO Ringing Office, both preferably via the appropriate county recorder. {Brit. BirdsXI: 505-563, November 1989] 505 506 Rare birds in Great Britain in 1988 1988 and earlier years The Committee has already dealt with 789 records for 1988, 78% of which have been accepted. A total of 445 records for 1988 and earlier years is still under consideration for a variety of reasons. The Rarities Committee is currently engaged upon reviews of both past and pending records of black-headed Yellow Wagtails Motacilla flava feldegg, Citrine Wagtails M. citreola and Olivaceous Warblers Hippolais pallida. The results of the recently completed review of records of Isabelline Shrikes Lanius isabellinus are contained within this report. Of most interest to readers are those records which involve potential 'firsts' for Britain and Ireland or birds which have not been recorded here for at least 50 years and are thus candidates for upgrading from Category B to Category A of the British and Irish list. Such records in England, Scotland and Wales are considered, in turn, by the British Birds Rarities Committee and by the British Ornithologists' Union Records Committee. Those pre-1988 records with which the BBRC is currently involved concern Madeiran Petrel Oceanodroma castro, Ross's Goose Anser rossii, Spotted Eagle Aquila clanga, South Polar Skua Stercomrius maccormicki, Least Tern Sterna antillarum, Cedar Waxwing Bombycilla cedrorum and Two-barred Greenish Warbler Phylloscopus plumbeitarsus. Excluding very old records which are under reconsideration, those pre-1988 records being investi­ gated by the BOURC concern Yellow-nosed Albatross Diomedea chlororhyn- chos, Falcated Duck Anas falcata, Marbled Duck Marmaronetta angustirostris, Barrow's Goldeneye Bucephala islandica, White-headed Duck Oxyura leuco- cephala, Royal Tern Sterna maxima maxima, Eagle Owl Bubo bubo, Egyptian Nightjar Caprimulgus aegyptius, Northern Mockingbird Mimus polyglottos, Blue Rock Thrush Monticola solitarius, Wood Thrush Hylocichla mustelina, Spectacled Warbler Sylvia conspicillata, Eastern Phoebe Sayornis phoebe, Chestnut Bunting Emberiza rutila, Painted Bunting Passerina ciris and Yellow-headed Blackbird Xanthocephalus xanthocephalus. Acknowledgments The accuracy and completeness of this report and the day-to-day work of the Rarities Committee are totally dependent upon the continued co-operation of individual observers and county and regional recorders, bird observatory wardens and reserve wardens and their committees. We should like to express our gratitude to them all. We should also like to thank the Irish Rare Birds Committee and its secretary, Patrick Smiddy, and the Northern Ireland Bird Records Committee and its secretary, Mrs Pat Vizard, for permission to include all accepted records of rare birds in Ireland and for supplying the details which enable us to provide a complete review and running totals of all rare bird records in the geographical unit of Britain and Ireland. Channel Islands rarity records are adjudicated by the Committee and accepted ones are included in this report, though not in the running totals, and we are grateful to Trevor Copp for liaising over all of these records. We are once again indebted to many individuals and organisations for assistance during the past year. For an amazing twelfth consecutive year, Mike Rogers has carried out the enormous task of compiling the report. As with the 1987 report, Rob Hume has written the species comments and Dave Britton has compiled the running totals for each species, a now- indispensable feature which he originated. Chris Heard joined the Committee two months Rare birds in Great Britain in 1988 507 early to cover for Iain Robertson, who was abroad. The Seabirds Advisory Panel, whose members are P. R. Colston, W. F. Curtis, J. Enticott, P. Harrison, and B. A. E. Marr, continued to provide the Committee with specialist advice, as have Per Alstrom, Peter Clement, Steve Howell, Lars Jonsson, Ron Kettle, Urban Olsson, Richard Porter, Lars Svensson and Claudia Wilds. The BTO, the NCC, the Rare Breeding Birds Panel, the RSPB and the British Museum (Natural History) have liaised over various matters. Photographs and slides, whether or not of sufficient quality for publication, always greatly assist the record assessment process. We continue to encourage their submission along with the written record and thank all photographers who have sent us pictures of rarities, a selection of which enhances this report. We are grateful to those observers who included drawings of rarities in their record submissions. Field sketches, regardless of the level of artistic merit, are of great value to the Committee. The same cannot be said of finished paintings, unless accompanied by the draft fieldwork, as all drawings and paintings should be representations of the bird in question and not of the species in general. Some of the drawings submitted with records grace the pages of this report. PGL Systematic list of accepted records The principles and procedures followed in considering records were explained in the 1958 report (Brit. Birds 53: 155-158). The systematic list is set out in the same way as in the 1987 report (81: 535-596). The following points show the basis on which the list has been compiled. (i) The details included for each record the characters' of the race concerned. are (1) county; (2) locality; (3) number of (iv) The three numbers in brackets after birds if more than one, and age and sex if each species' name refer respectively to the known (in the case of spring and summer total number of individuals recorded in records, however, the age is normally given Britain and Ireland (excluding those 'At only where the bird concerned was not in sea') (1) to the end of 1957, (2) for the period adult plumage); (4) if trapped or found dead since the formation of the Rarities Commit­ and where specimen is stored, if known; (5) tee in 1958, but excluding (3) the current date(s); and (6) observer(s) up to three in year. The decision as to whether one or number, in alphabetical order. In accord­ more individuals was involved is often dif­ ance with our declared policy (see Brit. Birds ficult and rather arbitrary, but the consensus 68: 1-4), the new county names have been of members is indicated by 'possibly the used, and observers are asked to bear this in same' (counted as different in the totals), mind when submitting records. 'probably the same' (counted as the same in (ii) In general, this report is confined to totals), or 'the same' when the evidence is records which are regarded as certain, and certain or overwhelming. An identical 'probables' are not included. In the case of approach is applied to records of the same the very similar Long-billed Limnodromus species recurring at the same locality after a scolopaceus and Short-billed Dowitchers L. lapse of time, including those which occur griseus, however, we are continuing to pub­ annually at the same or a nearby site. In lish indeterminate records, and this also considering claims of more than one indi­ applies to observations of pratincoles Glar- vidual at the same or adjacent localities, the eola and of such difficult groups as albatros­ Committee usually requires firm evidence ses Diomedea and frigatebirds Fregata. before more than one is counted in the (iii) The sequence of species, English totals. A detailed breakdown of the figures names and specific nomenclature follow The for previous years is held by the Honorary 'British Birds' List of Birds of the Western Pakarctic Secretary. (1984). Any sight records of subspecies (v) The world breeding range is given in (including those of birds trapped and re­ brackets at the beginning of each species leased) are normally referred to as 'showing comment. 508 Rare birds in Great Britain in 1988 White-billed Diver Gauia adamsii (18, 103, 6) Cornwall St Ives Bay, adult, 8th to at least 22nd February (B.