Larks to Hirundines

Skylark Alauda arvensis

Skylark comprises eleven subspecies. However, there is significant clinal variation in both colouration and biometrics (Cramp et al. 1988). Furthermore, genetic analysis fails to support the current taxonomy, identifying instead two major clades perhaps best treated as species – ‘Skylark’ A. arvensis in the west (though including Asian dulcivox) and ‘Pekin Skylark’ A. pekinensis in the east (Zink et al. 2008).

Nominate arvensis (also occurring in north and central Europe and east to the Urals) is a common breeder and winter visitor in Britain. A number of other subspecies are potential vagrants and several have been suspected here (Seago 1980, Votier & Shepherd 1999, Wallace et al. 2001). These include cantarella from southern Europe and dulcivox from the Urals and lower Volga to the northern Altai and northern Kazakhstan (Lees & Ball 2011).

However, given the problematic taxonomy and the degree of variation in this species, a firm subspecific identification beyond the breeding range is probably impossible.

Claims of vagrant subspecies are welcomed if accompanied by a ringing recovery which might help to identify a geographical origin and therefore a subspecies (or at least a subspecies pair or group). (updated Dec 2017 AMS).

References

Cramp, S. et al. 1988. The Birds of the Western PalearcticVol. 5. Oxford University Press, Oxford.

Lees, A. C. & Ball, A. 2011. Shades of grey: ‘eastern’ Skylarks and extralimital subspecies identification. British Birds 104: 660-666.

Seago, M. J. 1980. Norfolk Bird Report 1979. Norfolk & Norwich Nat. Soc. 25: 109-128.

Votier, S., & Shepherd, K. 1999. ‘Eastern’ Skylark, Sheringham, 5th October 1998. Norfolk Bird Club Bulletin 34: 11-14.

Wallace, D. I. M., McGeehan, A., & Allen, D. 2001. Autumn migration in westernmost Donegal. British Birds 94: 103-120.

Zink, R. M., Pavlova, A., Drovetski, S. & Rohwer, S. 2008. Mitochondrial phylogeographies of five widespread Eurasian bird species. J. Orn. 149: 399-413.

 

Shore Lark Eremophila alpestris

Shore Lark exhibits very significant variation in plumage and biometrics, with over forty subspecies described, over half of which are Nearctic. Amongst the Palearctic subspecies, flava breeds across northernmost Europe and Asia but all the other subspecies inhabit more southerly montane and desert regions. The taxonomy of the Shore Lark group is in a state of flux, however, with DNA evidence indicating the potential for six species to be recognised, five in the Palearctic and one in the Nearctic (Drovetski et al. 2014). Under this arrangement flava would become a monotypic species, with all the Nearctic subspecies treated as ‘North American Horned Lark’ E. alpestris.

Only flava is on the British List. It is a winter visitor in small and variable numbers and a very rare breeder. ‘North American Horned Lark’ was formerly included on the British List on the basis of a specimen obtained by Meinertzhagen from South Uist, Western Isles but was subsequently removed. However, some of the Nearctic subspecies (notably east Canadian alpestris and north Canadian hoyti) are potential vagrants. Candidate ‘Horned Larks’ were on the Isles of Scilly in October 2001 (Small 2002), on South Uist, Western Isles in October 2014 and at Staines Reservoir, Surrey in November 2017. Other candidates have been described in County Down, Northern Ireland in 1998 (Garner 1999) and in Iceland in 1981 (Pétursson & Ólafsson 1999).

Subspecific variation within ‘Horned Lark’ is extensive and complex and the separation of Nearctic birds from flava is not straightforward. Observers should pay particular attention to the precise patterning of the face, upperparts, wing coverts and underparts. Biometrics and vocalisations might potentially be useful.

Claims of ‘Horned Lark’ are welcomed if accompanied by detailed notes and good photographs. Research into identification is ongoing but acceptance based on this evidence to an alpestris/hoyti subspecies pair might be possible. A ringing recovery might enable attribution to a particular subspecies. (updated Dec 2017 AMS).

References

Drovetski, S. V., Rakovic´, M., Semenov, G., Fadeev, I. V., Red’kin, Y. A. 2014. Limited Phylogeographic Signal in Sex-Linked and Autosomal Loci Despite Geographically, Ecologically, and Phenotypically Concordant Structure of mtDNA Variation in the Holarctic Avian Genus Eremophila. PLoS ONE 9(1): e87570. doi:10.1371/journal.pone.0087570.

http://www.surfbirds.com/ID%20Articles/smallhlark/smallhlark0504.html.

Garner, M. 1999. An interesting Shore Lark in Ireland. Birding World 12: 152-154.

Pétursson, G. & Ólafsson, E. 1999. A probable Northern Horned Lark in Iceland. Birding World 12: 375-376.

Small, B. 2002. The Horned Lark on the Isles of Scilly. Birding World 15: 111-119.

 

Short-toed Lark Calandrella brachydactyla

Eight subspecies are recognised though there is significant clinal variation in colouration and biometrics and the boundaries between the subspecies are potentially arbitrary. Furthermore, much of the species’ variation is thought to be plumage adaptation to habitat type whilst wear and bleaching further add to the difficulty of subspecies definition (Cramp et al. 1988).

The species is a scarce migrant to Britain but none have so far been identified to subspecies. Birds of both southern and eastern origin are assumed to occur, presumably including at least nominate brachydactyla from the Mediterranean and longipennis from southern Russia.

However, given the problematic taxonomy and the degree of variation in this species, a firm subspecific identification beyond the breeding range is probably impossible.

Claims of vagrant subspecies are welcomed if accompanied by a ringing recovery which might help to identify a geographical origin and therefore a subspecies (or at least a subspecies pair or group). (updated Dec 2017 AMS).

References

Cramp, S. et al. 1988. The Birds of the Western PalearcticVol. 5. Oxford University Press, Oxford.

 

Swallow Hirundo rustica

Swallow comprises eight subspecies. Nominate rustica occurs widely across the Palearctic from the Atlantic to Siberia and western China, transitiva in Lebanon, southern Syria and Israel and savignii in Egypt. Eastern Asia is inhabited by four intergrading subspecies – tytlerigutturalis, saturata and mandschurica. The eighth subspecies – erythrogaster (‘American Barn Swallow’) – breeds in North America. Genetic studies cut across the current taxonomy, identifying three major clades – in Europe/western Asia, eastern Asia and North America.

Nominate rustica is an abundant breeder in Britain but no other subspecies is on the British List. However, some are presumably potential vagrants and birds resembling transitiva and erythrogaster have been reported in Britain (Kehoe 2006). The latter has reached the Azores (Jiguet & Zucca 2005).

Identification is not straightforward, however. The subspecies transitiva differs from rustica only in the intensity of colour on the underparts. However, transitiva-like individuals occur within populations of nominate rustica so it is not clear how transitiva might be identified in a vagrant context. The subspecies erythrogaster lacks the dark breast-band in both adult and juvenile plumage but Asian birds may also lack this feature. Biometrics might provide useful evidence in some cases.

Claims of transitiva or savigni should be accompanied by a ringing recovery. Claims of erythrogaster or any of the Asian subspecies are welcomed if accompanied by detailed notes and good photographs and might be acceptable to a broad subspecies group. However, more specific identification would require a ringing recovery (or potentially biometrics). (updated Dec 2017 AMS).

References

Kehoe, C. 2006. Racial identification and assessment in Britain. British Birds 99: 619-645.

Jiguet, F, and Zucca, M. 2005. The American Barn Swallows on the Azores – a new Western Palearctic bird. Birding World 18: 475-478.

Turner, A. K. & Rose, C. 1989. Swallows & Martins: An Identification Guide and Handbook. Helm, London.

Zink, R. M., Pavlova, A., Rohwer, S. & Drovetski, S.V. 2006. Barn swallows before barns: population histories and intercontinental colonization. Proc. R. Soc. B 273: 1245–1251.

 

House Martin Delichon urbicum

House Martin comprises three subspecies. Nominate urbicum breeds from Europe east to western Siberia where it intergrades with lagopodum of East Asia. The subspecies meridionale breeds in North Africa and southern Europe to south-central Asia.

Nominate urbicum is a very common summer visitor to Britain. The subspecies lagopodum is not on the British List but its occurrence has been suspected whilst meridionale is presumably a potential vagrant.

Identification of lagopodum hinges on the presence of fully white uppertail coverts and a shallow tail fork, the main problem being the elimination of an aberrantly-plumaged nominate bird. The subspecies meridionale differs from nominate urbicum only in biometrics, being smaller, expressed most obviously in a short wing and tail.

Claims of lagopodum are welcomed if accompanied by detailed notes and good photographs. A claim of meridionale would have to rely on biometrics. (updated Dec 2017 AMS).

References

Cramp, S. et al. 1988. The Birds of the Western PalearcticVol. 5. Oxford University Press, Oxford.

 

Red-rumped Swallow Cecropis daurica

Red-rumped Swallow comprises eight subspecies, one predominantly in the Western Palearctic, four in Asia (known collectively as ‘Asian Red-rumped Swallow’) and three in Africa. Of relevance here are rufula, breeding across southern Europe, North Africa and south-west Asia, nominate daurica, breeding in at least north-east Kazakhstan and Mongolia, and japonica in at least the Russian Far East, east and north-east China, Korea and Japan. The latter two subspecies intergrade and the limits of their respective ranges are not clear. The taxonomy of this group is debated, the Asian subspecies showing clear plumage differences from rufula yet more modest differences from Striated Swallow C. striolata.

The subspecies rufula is a scarce migrant in Britain. A bird of East Asian origin (accepted as daurica/japonica) is on the British List on the basis of a bird on Sanday, Orkney and then on Skye, Highland in June 2011 (Hudson et al. 2013). ‘Asian Red-rumped Swallows’ have also reached Norway, Sweden and Finland (A. Eriksson pers. comm., Thorne 2014).

Given good views, identification of daurica/japonica can be straightforward. Observers should concentrate on the face and nape pattern, the colour of the rump and the degree of streaking on the underparts.

Claims of this subspecies pair are welcomed if accompanied by detailed notes and preferably good photographs. A ringing recovery might enable attribution to subspecies. (updated Dec 2017 AMS).

References

Hudson, N. & the Rarities Committee. 2013. Report on rare birds in Great Britain in 2012. British Birds 106: 570-641.

Thorne, S. 2011. An Asian Red-rumped Swallow in Orkney – the first for Britain. Birding World 24: 382-383.

Thorne, R. & S. 2014. ‘Asian Red-rumped Swallow’ in Orkney and Highland, new to Britain. British Birds 107: 405-412.

Tveit, B. O. 2011.  Identification of Asian Red-rumped Swallow and the first records for Norway and Britain. Birding World 24: 327-341.