Report on rare birds in Great Britain in 2011 Nigel Hudson and the Rarities Committee his is the 54th annual report of the to submit any well-documented older records British Birds Rarities Committee. The for consideration so that their true status can Tyear 2011 was an exceptional one for be reflected more clearly. As the previous rare birds, perhaps surpassed only by 2008 examples show, even records from more than for the range of taxa recorded. A number of 50 years ago can prove acceptable if suitable potential ‘firsts’ from 2011 are still under evidence is provided. consideration, including White-winged The rarest birds featured in this year’s Scoter Melanitta deglandi, Slaty-backed Gull report are as follows: Larus schistisagus, Asian Red-rumped 2nd Madeiran Petrel Oceanodroma castro, Swallow Cecropis daurica daurica/japonica Short-toed Eagle Circaetus gallicus and and Eastern Black Redstart Phoenicurus Eastern Crowned Warbler Phylloscopus ochruros phoenicuroides – but even in the coronatus absence of these mega rarities the report 3rd Purple Gallinule Porphyrio martinica, includes a mouth-watering variety of avian Siberian Blue Robin Larvivora cyane, strays from around the globe. The Eastern Rufous-tailed Robin L. sibilans and White- Black Redstarts are particularly interesting throated Robin Irania gutturalis because, in addition to considering the well- 4th Sandhill Crane Grus canadensis and watched birds in autumn 2011, we are American Black Tern Chlidonias niger reviewing a record from Kent in 1981. This surinamensis reassessment follows the provision of new images, showing details of the wing formula 5th Ovenbird Seiurus aurocapilla that were not available in the original sub- 5th & 6th Scarlet Tanager Piranga olivacea mission (see Brit. Birds 105: plates 262 & 6th Audouin’s Gull Larus audouinii and 263). The opportunity to assess and publish Pacific Swift Apus pacificus older records in this report extends to several 6th & 7th Spectacled Warbler Sylvia Black-bellied Dippers Cinclus c. cinclus and a conspicillata Killdeer Charadrius vociferus on Scilly from 7th Wilson’s Snipe Gallinago delicata and 1980, although these start to look positively Northern Waterthrush Parkesia contemporary when compared to the Dorset noveboracensis Great Reed Warbler Acrocephalus arundi- 8th Western Sandpiper Calidris mauri, naceus sound-recorded in 1961! We have Siberian Rubythroat Calliope calliope and included statistics in square brackets for Spanish Sparrow Passer hispaniolensis accepted records of Northern Long-tailed Tit Aegithalos c. caudatus, Eastern Subalpine 10th Oriental Turtle Dove Streptopelia Warbler Sylvia cantillans albistriata and orientalis and Veery Catharus fuscescens Black-bellied Dipper for previous years, since A trio of highly prized eastern chats we recognise that these do not reflect the rubbing shoulders with five Nearctic passer- genuine status of these forms. Current evi- ines with fewer than ten records to their dence, in terms of the rate of occurrence, name illustrates the quality of the autumn suggests that these forms should be consid- arrivals in 2011. Short-toed Eagle, White- ered as rarities, and we encourage observers throated Robin and Spectacled Warbler 556 © British Birds 105 • October 2012 • 556–625 Report on rare birds in Great Britain in 2011 emphasise the quality of overshoots arriving Great Snipe Gallinago media and Royal Tern from the south and southeast. Shorebird Sterna maxima, and of course the Druridge enthusiasts were not disappointed, with great Bay Slender-billed Curlew Numenius variety and some exceptionally rare plumages tenuirostris. A range of potential Pacific gulls in a British context, the long-staying juvenile continues to absorb our attention, including Sharp-tailed Sandpiper Calidris acuminata records of Slaty-backed Gull and Thayer’s and first-winter Western Sandpiper C. mauri Gull L. (glaucoides) thayeri. Similarly, a series among the memorable highlights. The of Elegant Tern S. elegans and ‘orange-billed’ former may have been a transatlantic arrival tern records await further research, as does a in Britain, perhaps associated with a large first-winter female Ficedula flycatcher from arrival of juvenile Long-billed Dowitchers Spurn, Yorkshire. Limnodromus scolopaceus. Influxes of Glossy Nonetheless, during the past 12 months Ibises Plegadis falcinellus and Red-flanked we have made progress on a series of difficult Bluetails Tarsiger cyanurus have become files, including a number of records of Ross’s almost expected, but the unprecedented Goose Anser rossii and Eastern Subalpine movement of juvenile Pallid Harriers Circus Warbler. The progress with the latter is part macrourus in the autumn was not antici- of a Herculean effort by Brian Small to sift pated. through our archives to try to identify all the The quality of the year 2011 is also potential candidates. We have started by reflected in the number of records handled assessing all those that were formally sub- by BBRC – 633, up from 526 in 2010. The mitted as this form in recent years. So far, we overall acceptance rate was 87.8%, compared have limited our acceptance criteria to the with 84.4% the previous year. more easily diagnosable males but it appears Taking into account the absence of White- that genetic analysis may help with females. billed Diver Gavia adamsii (33 records in The challenge with Ross’s Geese has involved 2008) and Cattle Egret Bubulcus ibis (168 in trying to make sense of their movements and 2008), which are no longer considered by the number of individuals involved. With the BBRC, it becomes clear that there were more relatively straightforward task of identifica- individual rarities in 2011 than in any pre- tion resolved, these will now be winging their vious year, although the number of taxa way to BOURC where the greater challenge involved just failed to reach the number in of attempting to assess their origins will be 2008. considered. The resolution of some long-standing Attentive readers perusing the Not Proven reviews and difficult records remains an section of the report will note the appearance ongoing challenge, notably those involving of the 1986 Fair Isle Saker Falcon Falco Macaronesian Shearwater Puffinus baroli, cherrug (following BOURC’s review that con- sidered that a hybrid could not be ruled out; BOURC 40th report) and the 1987 Eastern 2011 2010 2009 2008 Phoebe Sayornis phoebe. The latter record has Acceptances not been reconsidered since the original – current year 568 467 459 660 assessment, but the decision appears not to Not Proven have been formally published in a BBRC – current year 65 59 62 67 report. Acceptances – previous years 74 56 104 103 Acknowledgments Not Proven BBRC continues to be supported financially by Carl – previous years 24 38 50 40 Zeiss Ltd, and their support for the past 31 years has been invaluable in enabling us to carry out our work. TOTAL 731 620 675 870 We are also grateful to the continued support of the RSPB. We wish to thank all the observers and photo - Corrections 4611 22 graphers who sent details of their observations to Number of taxa in BBRC, either directly or via County Recorders or the accepted records 127 117 113 134 BirdGuides and/or Rare Bird Alert online galleries. Once again we wish to express our heartfelt thanks to county British Birds 105 • October 2012 • 556–625 557 Hudson et al. and regional recorders and their records committees for Steven Wytema. John Marchant has continued in his role the invaluable work that they undertake in supporting as Archivist and Brian Small as Museum Consultant. BBRC. Thanks also go to all those individuals who Keith Naylor provided valuable support to the BBRC updated information on earlier sightings through corres - Secretary and we also thank Ross Ahmed and Andy pondence following the posting of work-in-progress files Musgrove for their significant efforts to support the on the BBRC website throughout the year. While they secretarial workload in recent years. We also thank the may not be acknowledged in the report, their Dutch Birding team for providing electronic copies of contribution remains very significant for improving the papers from that journal for reference; the BTO for their accuracy of the information provided. BirdGuides has continued generosity in providing space and facilities for continued to assist the Committee, particularly by our archive; and all the staff at the NHM, Tring, for their enabling the submission of photographs for consid - continued support for our work and allowing unlimited eration by BBRC, and we are also grateful to Dominic access to the specimens in the collection. Mitchell and the staff at Birdwatch magazine for assisting Finally, we are extremely grateful to all the the Committee’s work. We thank the following in observers who have submitted records via the online particular for their support in various ways during the form on the BBRC website (www.bbrc.org.uk). We year: Steve Arlow, Jez Blackburn, Mark Brazil, Martin believe we have ironed out the inevitable gremlins that Collinson, Mark Constantine, Magnus Robb and the appeared with the website redevelopment and we now Sound Approach team, Harvey van Diek, Steve Dudley, recommend and encourage all observers to use this Chris Gibbins, Rob Gordijn, Andrew Harrop, Leo system of record submission. Heemskerk, Wietze Janse, Justin Jansen, Phil Jones/Rye Bay Ringing Group, Chris Kehoe, Peter Kennerley, Paul Leader, Paul Lehman, John Martin, Dorian Moss, Killian Adam Rowlands Mullarney, Keith