Black Kite Milvus migrans
In the Palearctic nominate migrans breeds across Europe and North Africa and lineatus (‘Black-eared Kite’) in eastern Asia.
Nominate migrans is a scarce migrant to Britain. The subspecies lineatus is not on the British List but 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 widespread intergradation across Russia, western Siberia and Central Asia (Forsman 2016, Lindholm & Forsten 2011). The former author recommends close scrutiny of the colour of the feet and cere, wing formula and under-primary pattern and, on adults, iris colour and the colour of the head feathering.
BBRC welcomes submissions of any individuals showing evidence of an eastern origin but it may only be possible to publish ‘promising’ birds as ‘held’. 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 Dec 2017 AMS).
References
Carter, I. 2007. The Red Kite. Arlequin Press.
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.
Forsman, D. 2016. Flight Identification of the Raptors of Europe, North Africa and the Middle East. Bloomsbury, London.
Lindholm, A. & Forsten, A. 2011. Black Kites Milvus migrans in Russian Altai. Caluta 2: 1-6.
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 kamtschatkensis. 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’ B. b. vulpinus and Long-legged Buzzard B. rufinus.
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 Dec 2017 AMS).
References
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.
Buzzard Buteo buteo
Common Buzzard occurs in a number of subspecies. Nominate buteo breeds 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. 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. The subspecies vulpinus 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. 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. Rough-legged Buzzard B. lagopus sanctijohannis, Long-legged Buzzard B. rufinus or Ferruginous Hawk B. regalis.
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 Dec 2017 AMS).
References
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.
