Birds of Prey

Black Kite Milvus migrans

At least six subspecies of Black Kite are recognised. In the Palearctic, nominate migrans breeds across Europe and North Africa. In eastern Asia it is replaced by lineatus (‘Black-eared Kite’). The subspecies aegyptius occurs across the Middle East. Species status has been proposed for lineatus (Wassink & Oreel 2007).

Nominate migrans is a scarce migrant to Britain. No other subspecies is on the British List but lineatus might be a potential vagrant. BBRC has received a submission for the bird in Lincolnshire and Norfolk in 2006/07 but not the widely reported bird in Powys in 2010.

The subspecies lineatus differs slightly from nominate migrans in size, structure and plumage but firm identification is difficult due to intergradation across eastern Russia, western Siberia and Central Asia (D. Forsman pers. comm.). Lindholm & Forsten (2011) provide a good summary of the problems involved. As a result, it has not been possible to determine characters which will safely separate a vagrant lineatus from an intergrade.

BBRC welcomes submissions of any individuals showing evidence of an eastern origin although, if promising, these will be ‘held’ until the taxonomic and identification difficulties can be resolved. Biometrics or details from a ringed or marked bird are likely to be necessary for acceptance. There will also potentially be issues of captive origin and of Black x Red Kite hybrids in assessing any claim of lineatus (Carter 2007). (updated Sept 2015).

References

Carter, I. 2007. The Red Kite. Arlequin Press.

Cramp, S. et al. 1977. The Birds of the Western Palearctic. Vol. 2. Oxford University Press, Oxford.

De Candido, R., Subedi, T., Siponen, M., Sutasha, K., Pierce, A., Nualsri, C. & Round, P. D. 2013. Flight identification of Milvus migrans lineatus ‘Black-eared’ Kite and Milvus migrans govinda ‘Pariah’ Kite in Nepal and Thailand. Birding ASIA 20: 32-36.

Forsman, D. 2003. Identification of Black-eared Kite. Birding World 16: 156-160.

Lindholm, A. & Forsten, A. 2011. Black Kites Milvus migrans in Russian Altai. Caluta 2: 1-6.

Wassink, A. &  Oreel, G. J. 2007. The Birds of Kazakhstan.

 

Northern Goshawk Accipiter gentilis

Goshawk variation is clinal and complex but three subspecies are recognised in Europe. Nominate gentilis occurs widely but is replaced by buteoides across northernmost Europe and northern Asia and by arrigonii on Corsica and Sardinia. The subspecies atricapillus (‘American Goshawk’) occurs in North America. This latter subspecies was previously on the British list but the two records (in Perthshire in 1869 and on the Isles of Scilly in 1935) have now been reviewed by BOURC and found to be unacceptable (BOU 2012, 2015).

The identification of atricapillus is dependent upon accurate documentation of the pattern of barring on the underparts of adults. There are few biometric clues. Identification is possibly further compromised by the potential presence of atricapillus genes (deriving from escapes and/or introductions) in the British population.

An acceptable claim of atricapillus should comprise notes and good photographs of a (preferably perched) adult bird which enable a clear assessment of the underparts pattern. Otherwise submissions should include details from a ringed or marked bird. The issue of potential captive origin is also highly relevant in any claim of this subspecies. (updated Jan 2016 AMS).

References

British Ornithologists’ Union Records Committee: 41st Report. 2012. Ibis 155: 204-207.

British Ornithologists’ Union Records Committee: 45th Report. 2015. Ibis 158: 202-205.

Cramp, S. et al. 1980. The Birds of the Western Palearctic. Vol. 2. Oxford University Press, Oxford.

Forsman, D. 1999. The Raptors of Europe and The Middle East. T & A. D. Poyser, London.

Kenward, R. 2006. The Goshawk. T. & A. D. Poyser.

Marquis, M. & Newton, I. 1982. The Goshawk in Britain. Brit. Birds 75: 243-260.

 

Common Buzzard Buteo buteo

Common Buzzard occurs in a variety of subspecies. Nominate buteo occurs across western Europe but is replaced by vulpinus (‘Steppe Buzzard’) in easternmost Europe and northern Asia east to Siberia. The boundary is reported to be shifting eastwards (Garner 2014).

Nominate buteo is a very common breeder in Britain but vulpinus is not on the British List. An earlier specimen record has recently been reviewed and found not to be acceptable (Harrop & Collinson 2003). See http://www.britishbirds.co.uk/wp-content/uploads/article_files/V96/V96_N05/V96_N05_P247_249_A008.pdf. Unlike nominate buteo, vulpinus is a very long distance migrant (reaching South Africa) and therefore a potential vagrant, indeed a number of claims have been received by BBRC.

Identification is problematic, however. Nominate buteo is highly variable, with a small proportion of British birds showing some plumage characters associated with vulpinus whilst  intergradation between the two subspecies is also reported. Vulpinus itself is also highly variable, with up to four distinct plumage morphs recognised – ‘grey-brown’, ‘rufous’, ‘dark rufous’ and ‘black’. The first-listed resembles nominate buteo so the best prospects for identification lie with the other plumage morphs. Biometrics and moult cycle differences are potentially helpful too. The identification issues are explored fully in van Duivendijk (2011).

Other potential identification problems include the elimination of Long-legged Buzzard (especially of the subspecies cirtensis), escaped Red-tailed Hawk and Common Buzzard x escaped Red-tailed Hawk hybrids. ‘Dark’ birds would need to be distinguished from other wild or escaped dark morph Buteos e.g. sanctijohannis Rough-legged Buzzard, Long-legged Buzzard or Ferruginous Hawk.

Claims of vulpinus should include detailed notes and good photographs but biometrics or details from a ringed or marked bird would provide more solid evidence. (updated November 2014 AMS).

References

Cramp, S. et al. 1980. The Birds of the Western Palearctic. Vol. 2. Oxford University Press, Oxford.

Forsman, D. 1999. The Raptors of Europe and The Middle East. T & A. D. Poyser, London.

Harrop, A. H. J. & Collinson, M. 2003. The 1864 Wiltshire ‘Steppe Buzzard’: A Review on behalf of the British Ornithologists’ Union Records Committee. Brit. Birds 96: 247-249.http://www.britishbirds.co.uk/wp-content/uploads/article_files/V96/V96_N05/V96_N05_P247_249_A008.pdf.

Shirihai, H. & Doherty, P. 1990. Steppe Buzzard plumages. Birding World 3: 10-14.

van Duivendijk, N. 2011. Steppebuizerd in Nederland: herziening, status en determinatie (Steppe Buzzard in the Netherlands: revision, status and identification). Dutch Birding 33: 283-293.

 

Rough-legged Buzzard Buteo lagopus

Rough-legged Buzzard has four subspecies. Nominate lagopus breeds across northern Europe and Asia but is replaced in North-east Asia by menzbieri and in Kamchatka by kamschatkensis. The subspecies sanctijohannis (‘Rough-legged Hawk’) breeds across northern North America. The Palearctic subspecies occur in a pale form only but sanctijohannis is dimorphic, occurring in a pale form similar to Palearctic birds and a less common dark form.

Nominate lagopus is a scarce winter visitor to Britain. ‘Rough-legged Hawk’ is not on the British List but it is a potential vagrant and occurrences here have been suspected (Millington 2001). There are confirmed records involving dark morph birds from Iceland, the Faeroes, the Azores and Ireland where a number of pale morph birds have also been seen on dates and in weather circumstances highly suggestive of a Nearctic origin (Jensen 2002, 2003, 2006, Mullarney & Murphy 2005, http://www.irbc.ie/reports/irbr/2005_IRBR.pdf).

The firm identification of pale morph sanctijohannis rests on biometrics. Dark morph birds, however, are more striking although they would need to be distinguished from other wild or escaped dark morph Buteos e.g. ‘Steppe Buzzard’ and Long-legged Buzzard.

Claims of dark morph sanctijohannis should include detailed notes and photographs. Claims of pale morph sanctijohannis should also include biometrics or details from a ringed or marked bird. Date and location might provide circumstantial supporting evidence. (updated Sept 2015 AMS).

References

Cramp, S. et al. 1980. The Birds of the Western Palearctic. Vol. 2. Oxford University Press, Oxford.

Forsman, D. 1999. The Raptors of Europe and The Middle East. T & A. D. Poyser, London.

Irish Rare Bird Report 2005. http://www.irbc.ie/reports/irbr/2005_IRBR.pdf.

Jensen, J-K. 2002. A Rough-legged Hawk off Greenland. Birding World 15: 348.

Jensen, J-K. 2003. A Rough-legged Hawk on the Faeroe Islands. Birding World 16: 20-21.

Millington, R. 2001. A possible Rough-legged Hawk on the Isles of Scilly. Birding World 14: 439-440.

Jensen, J.-K. 2006. Are dark morph Rough-legged Hawks overlooked in Europe? Birding World 19: 208-209.

Mullarney, K. & Murphy, J. 2005. The Rough-legged Hawk in Ireland. Birding World 18: 503-504.