Review of Category D species

As a result of BOURC’s ongoing review of Category D species, two species have already been added to Category A – Hooded Merganser (BOURC 37th report, Ibis 151: 224-230) and Asian Brown Flycatcher (BOURC 38th Report, Ibis in prep.) and five species have been moved to Category E – Cinereous Vulture, Northern Flicker, White-winged Snowfinch, Chestnut Bunting and Blue Grosbeak (BOURC 37th report, Ibis 151: 224-230; BOURC 38^th Report, Ibis in prep.). In addition, Baikal Teal will be added to Category A in the BOURC 38^th Report (Ibis, in prep.).

The following species, along with Bald Eagle as previously announced (Ibis 151: 224-230), are to be retained in Category D:

Great White Pelican Pelecanus onocrotalus

Four records: Norfolk, 1964; Essex, Kent, Humberside,1975; Kent, Essex, Yorkshire, Angus, Moray, 2006 and a second individual in Norfolk, Lancashire, Northumberland, Cambridgeshire, Suffolk, Denbighshire, Anglesey.

A review was prompted by records of two birds in 2006 and a recent paper on out-of-range pelicans in Europe (Ibis 150: 606-618).

The only record now retained in Category D is the bird observed at Hanningfield, Essex, and later at Fordwich, Kent, and the River Humber in July 1975.

Mugimaki Flycatcher Ficedula mugimaki

One record: Stone Creek, Humberside, on 16-17 November 1991.

Retain in Category D.

Unlike Brown Flycatcher, this species is known to have been in trade at the time of the occurrence. The Committee was unable to find compelling evidence of long-distance westwards vagrancy by this species.

There is some doubt about the provenance of the record from Treviso, Italy, on 29 October 1957, and the first non-controversial West Palearctic record involved an adult male seen near Neftekamsk, Russia, on 2 August 2007 (per M. Wilson).

Daurian Starling Agropsar sturninus

Two records: Fair Isle, Shetland, 7-28 May 1985; Durness, Highland, 24-27 September 1998.

Both records retained in Category D.

The two accepted Western Palearctic records (from Norway and the Netherlands) have both involved first-winter birds in autumn. This species is regularly found in trade, and there were concerns about the relatively early spring date of the Fair Isle record and the age (probably adult) of the Durness bird.

Red-headed Bunting Emberiza bruniceps

Formerly on the British List, this species was removed in 1968 on the basis that all records could have involved birds originating from trade.

There has still not been an acceptable record of an autumn first-winter bird, and this species was still in trade immediately prior to the record from Monreith, Dumfries & Galloway, 8-9 June 2004. Red-headed Bunting is reportedly still in trade in the USA, but any British occurrence which presents little overt reason to suspect captive origin following the complete ban on the importation of wild-caught birds into the EU (effective from 1 July 2007) will be looked at very seriously.

See full list of Category D species here.

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Changes to Category A of the British List

A joint BOURC and BBRC announcement


The British Ornithologists’ Union Records Committee (BOURC) has accepted the following to Category A of the British List:

Pacific Diver Gavia pacifica
Juvenile, near Harrogate, North Yorkshire, 12 January-4 February 2007.

Pacific Diver was recently split from Black-throated Diver Gavia arctica (Knox et al., 2008; Taxonomic recommendations for British birds. Ibis 150, 833–835). It breeds in northern parts of North America and along a narrow coastal strip of north-east Siberia, and winters along the Pacific coast of North America from Alaska to Mexico and in Asia off Japan and south to eastern China.

This bird’s arrival at an inland locality made it possible to scrutinise the bird closely and confirm (amongst other features) that the feathers of the anterior tibial tract were dark. The finders are to be congratulated for realising that the bird was not ‘just’ a Black-throated Diver. There have already been two subsequent records, so this species may have been overlooked previously in circumstances which did not allow the critical features to be rigorously assessed.

It should be placed after Black-throated Diver Gavia arctica on the British List.


Yellow-nosed Albatross Thalassarche chlororhynchos
Immature, Brean, Somerset, 29-30 June 2007; same, Manton, near Messingham Lincolnshire, 2-3 July.

There are two populations of Yellow-nosed Albatross: Atlantic chlororhynchos which is found mainly in the south Atlantic, and Indian bassi which is found mainly in the south-east Indian Ocean.

The bird in Somerset was taken into captivity, and the close-up photographs enabled it to be identified on the basis of the bill pattern and culminicorn shape as Atlantic chlororhynchos, which has also occurred in Norway (on 13 April 1994) and had accumulated 18 records along the Atlantic coast of North America by 1981. Further records would not be surprising, though excellent views and preferably photographs are likely to be required to establish which taxon is involved.

The taxonomy of the Thalassarche albatrosses is currently under review by the BOURC's Taxonomic Sub-committee (TSC).

It should be placed after Black-browed Albatross Thalassarche melanophris on the British List.


Glaucous-winged Gull Larus glaucescens
Third-winter, Gloucester Landfill Site, Hempsted, Gloucestershire, 15-16 December 2006, trapped, ringed and photographed. Subsequent sightings: Ferryside, Camarthen, 2-5 March 2007; Hempsted, Gloucestershire, 16-17 March; Beddington, London, 18 April.

The normal range of this species extends from the Commander Islands east through the Aleutians, Pribilofs and south Bering Sea to southern Alaska and south-east to north Oregon. It winters from the Bering Sea to northern Japan and Baja California.

Feathers collected from the bird were sent to Prof. P de Knijff (Leiden University) for analysis. The results, which have been deposited with GenBank, clearly placed it in the Beringian clade. Although it was impossible to rule out genetic influence from other taxa with 100% certainty, the bird did not show any features which were demonstrably those of a hybrid, and American expert opinion supported identification as Glaucous-winged Gull.

There had been two previous records in the Western Palearctic, from the Canary Islands and Morocco, and there has already been a subsequent British record.

It should be placed after Iceland Gull Larus glaucoides on the British List.


White Wagtail Motacilla alba leucopsis
Male, Seaham, County Durham, 5-6 April 2005.

Colloquially known as Amur Wagtail, this taxon breeds in south-easternmost Russia, south through Ussuriland, north-east China, North and South Korea and south-western Japan to Taiwan and eastern and southern China. It winters in southern China and southward through Taiwan, Hainan, Indochina, Myanmar, the Andaman Islands, Bangladesh, northern India and Nepal.

This was one of the most remarkable records considered by the Committee in recent years. Although it was considered an unlikely vagrant, no evidence of this taxon in the captive bird trade was found, and there has been a subsequent record from Norway (in November 2008)


Asian Brown Flycatcher Muscicapa dauurica
First-summer, Fair Isle, Shetland, 1-2 July 1992.

Nominate dauurica breeds in central Siberia and south-east Russia, northern Mongolia, north-east China, North Korea, Sakhalin and Japan and winters in southern China, south-east Asia, the Philippines and Greater Sundas.

This species has been recognised as a potential vagrant for a long time, and there have been several previous claims. The identity of the Fair Isle bird was never in doubt, and the subsequent occurrence of birds in autumn in 2007 and 2008 prompted a review of this record. Although the date of the record is surprising, it followed a June dominated by continental anticyclonic conditions with an associated easterly airstream. One of several spring Greenish Warblers Phylloscopus trochiloides arrived as late as 30 June, and a Bluethroat Luscinia svecica and two Red-backed Shrikes Lanius collurio arrived on the same day as the Brown Flycatcher. The worn condition of the bird’s plumage was consistent with that shown by museum specimens collected in June and July, and no hard evidence of this species in captive bird trade in the UK or elsewhere in Europe has been found.

All the British records have involved nominate dauurica.

It should be placed before Spotted Flycatcher Muscicapa striata on the British List.


Also considered

Brown Shrike Lanius cristatus cristatus
Adult male, Whalsay, Shetland, 19-24 September 2004.

Nominate cristatus breeds in eastern Siberia from the Russian Altai and Ob river eastwards through northern and eastern Mongolia to the Pacific, and winters from India to Thailand and Malaysia.

There were initially some concerns about excluding the possibility that this bird might be ‘confusus’, but reference to skins showed that it was a fairly typical example of nominate cristatus.


The British List now stands at 587 species
(Category A = 568; Category B = 9; Category C = 10)

Ends

British Ornithologists’ Union

British Birds Rarities Committee

Wilson's Snipe admitted to the British List

Joint BOURC & BBRC Announcement

American Common Snipe (Wilson’s Snipe)
Gallinago gallinago delicata

Juvenile, St Mary’s, Isles of Scilly
9 October 1998 to 7 April 1999

The British Ornithologists’ Union Records Committee (BOURC) has accepted the record of a juvenile American Common Snipe (‘Wilson’s Snipe’) Gallinago gallinago delicata on St Mary’s, Isle of Scilly, from 9 October 1998 until 7 April 1999 as the first record of this taxon for Britain. The BOURC’s Taxonomic Sub-committee is actively reviewing the taxonomic status of Wilson’s Snipe and its findings will be published shortly.

The Nearctic counterpart of Eurasian Common Snipe (including nominate gallinago and faeroeensis), Wilson’s Snipe has a very extensive breeding distribution across northern North America, with a population possibly exceeding 5 million birds. Some birds from Newfoundland are thought to fly south across the western Atlantic in autumn towards wintering areas in Central or South America, so transatlantic vagrancy is to be expected. There have been other Western Palearctic records of vagrants from Ireland, France, the Canary Islands and the Azores (where at least 13 were reportedly shot in autumn 2007).

Already, there are several subsequent claims from Britain, and Wilson’s Snipe may prove to be as regular a vagrant as some other Nearctic waders, but establishing identification is very difficult. Essentially, the shape and pattern of the outer tail feathers need to be carefully noted, and preferably photographed. Other important supporting features include the number of tail feathers (normally 16 in delicata), the narrower white trailing edge of the secondaries, and broader dark barring on the axillaries. A paper summarising the differences between delicata, faeroeensis and nominate gallinago was recently published (British Birds 101: 189-200).

Bob McGowan, Chairman of BOURC, commented “Wilson’s Snipe was deleted from the British List as recently as 1993 when Richard Meinertzhagen’s record from South Uist (1920) and one from Lancashire (1957) were rejected after review. Yet this snipe has remained a fairly strong candidate for readmission to the List; it is a ubiquitous breeder in North America and some populations migrate long distances along the eastern seaboard. Nevertheless, even when considered as a possible or likely vagrant, Wilson’s Snipe presents a considerable identification problem in the field. Although up to 14 characters have been variously postulated as identification aids, plumage variation in delicata (and faeroeensis and nominate gallingo) means that the most of these characters have an element of overlap; for example a ‘typical’ delicata pattern on axillaries and underwing is not necessarily indicative of delicata as some individuals of the other two taxa exhibit similar plumage. Fortunately for BOURC, a considerable effort had been made by BBRC and its consultants to rationalise and define the precise diagnostic characters essential for judging the record. Central to BOURC’s consideration was the opportunity to assess the shape and width of the bird’s outer tail feathers, perhaps the most critical feature in the file. This was made possible because excellent photographic images of the fanned tail formed part of the submission. With such thorough background information, BOURC was satisfied that identification had been established beyond doubt, and with negligible escape risk for the taxon, it was admitted Category A.”

Adam Rowlands, Chairman of BBRC, commented “This record was particularly challenging for BBRC to assess and was considered not proven at one stage (British Birds 98: 630 & 692). However, it was called for a further review when Killian Mullarney and Ian Lewington commented on a draft paper outlining the reasons for the BBRC decision. Their valuable input encouraged a re-evaluation of the file and the decision was overturned. Whilst it may well be a more regular vagrant than published records indicate, the variation within the nominate form and delicata does mean that some field claims may still be difficult to confirm. Observers faced with a putative delicata should endeavour to get high-quality photographs documenting the pattern of the outer tail-feather, axillaries, underwing, and white tips to the secondaries. The shape of the outer tail feather is also valuable as are the number of tail feathers, which may be possible to determine in exceptional photographs. Photographs of two or three of these features on a bird that shows the full suite of supportive characters would also assist a claim. It is of great credit to the original finders and photographers of the Scilly bird that the detail obtained allowed the identification to be established beyond doubt.”

American Common Snipe is listed on the British List as follows –

Common Snipe A
Snipe
Gallinago gallinago (Linnaeus)
RB MB WM PM gallinago (Linnaeus)
RB MB WM PM faeroeensis (C.L. Brehm)
V delicata (Ord). One record: juvenile, St Mary’s, Isles of Scilly, 9 October 1998 to 7 April 1999.

The British List remains on 580 species
(Category A = 560; Category B = 10; Category C = 10).

Ends

British Ornithologists’ Union

British Birds Rarities Committee