BOURC decisions (5 Feb 2018)

5 February 2018

The British Ornithologists’ Union Records Committee (BOURC) has placed the following in Category E:

Hooded Merganser Lophodytes cucullatus
Second-calendar-year or older, Holme and Titchwell RSPB, Norfolk, 25 January to 10 April 1997 (photographed).

This record was considered as a potential first for Britain, as it predates the Outer Hebrides October-November 2000 record. The species is widely kept and numerous in captivity, and has a track record which includes a series of proven escapes. In these circumstances, there is reasonable doubt about the origin of most British records. This along with the south-east locality in East Anglia, where some of our more regular vagrant Nearctic wildfowl species are rare, failed to convince the Committee that this bird was of wild origin. The record did not receive any votes for Category A and was placed in Category E.

Breeds across North America, with winter movements of birds from northerly parts of the range.

Bearded Vulture Gypaetus barbatus
Second-calendar-year, Sudbrook, Gwent, 12 May 2016; same Brent Moor, South Brent, Devon, 16 May 2016; same Cookworthy Moor Plantation, Devon, 20 May 2016; same Breney Common near Helman Tor, Cornwall, 23 May 2016; other dates as wandered southern England (photographed).

The appearance of a number of wandering Bearded Vultures during the past few years in north-west Europe, well away from their mountain breeding ranges in the Alps and the Pyrenees, has generated wide interest, particularly in light of similar observations of Griffon Vultures Gyps fulvus which have been shown to have a wild origin. However, it seems highly likely that all these wandering Bearded Vultures derived from introduced Alpine populations, which are slowly increasing but as yet not self-sustaining, rather than from natural populations in the Pyrenees. This has resulted in the species being placed in Category E.

The same categorisation has been adopted by other national bird committees in north-west Europe where Bearded Vultures have been reported, including Belgium, where the same individual seen in Britain was observed (e.g. see Rare Birds in Belgium in 2016).

Resident in mountainous regions. The nominate subspecies barbatus breeds in southern Europe and north-west Africa, from Turkey through the Himalayas to north-east China and Mongolia; meridionalis in western Arabian Peninsular, and north-east, East and South Africa. Reintroduction programmes are underway in the Alps within the former breeding range; numbers remain small but young have been produced (see www.4vultures.org).

Demoiselle Crane Grus virgo
Third-calendar-year or older, Mockerkin Tarn, near Ullock, roaming to Cockermouth, Cumbria, (22 Feb) 13-22 March 2016 (photographed).

The species is widely kept in collections and, as yet, there is little evidence for it occurring naturally in north-west Europe. Small numbers migrate through the eastern Mediterranean to and from their African wintering grounds. This individual appeared at a time inconsistent with migration times, and without substantiation to support a natural origin the record was placed in Category E. The species was already in Category E due to a number of previous confirmed escaped records.

Breeds from eastern Turkey, the Ukraine and south-west Russia to Mongolia and northern China, with western birds migrating to winter in central eastern Africa, and eastern birds wintering in the Indian subcontinent.

Common Myna Acridotheres tristis
Adult, Landguard Bird Observatory, Suffolk, 16 May 2014 (photographed).

This bird was found next to a container port where large numbers of boats arrive from around the world. Though it was highly unlikely that it had arrived naturally as a vagrant, it was possible that the bird had instead been transported aboard a boat. As such it might have derived from natural populations, or perhaps more likely from nearer introduced populations in the Arabian Peninsula or Europe. However, it could also be an escape from captivity, as the species is widely kept. With the most likely explanations therefore being either transported from an introduced population or an escape from captivity, the committee voted unanimously for a captive origin with, consequently, the record being placed in Category E. The species was already in Category E, following a number of earlier records of escaped birds.

Cosmopolitan. Natural resident populations from central Asia, Pakistan, India to south-east Asia. A highly invasive species, with introduced populations throughout the world including Australia, New Zealand, southern Africa, Madagascar, Florida, the Arabian Peninsula and Europe, not all of which are self-sustaining.

View Category E

Further details of these decisions will be published as part of the BOURC’s 49th report due to be published in IBIS in October 2018. Upon publication of these decisions, the British List stands at 616 species (Category A = 598; Category B = 8; Category C = 10).

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