Larks to Hirundines

 

Short-toed Lark Calandrella brachydactyla

Eight subspecies are generally recognised though there is significant clinal variation in colouration and biometrics and the boundaries between them 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 group). (updated February 2015 AMS).

References

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

 

Skylark Alauda arvensis

Skylark comprises around thirteen subspecies, eight in the Western Palearctic and five in the Eastern Palearctic. However, there is significant clinal variation in both colouration and biometrics and the current taxonomy may overstate their number (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. pekiensis in the east (Zink et al. 2008).

Two subspecies are sometimes identified as occurring in Britain – nominate arvensis, a common breeder and winter visitor (also occurring in north and central Europe and east to the Urals), and scotica, breeding in north-west Scotland and north-west England (also in Ireland and the Faeroes). However, only nominate arvensis (and not scotica) is officially on the British List. 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. (updated Sept 2015 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 at least 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 (Cramp et al. 1988). 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 (including, for example, east Canadian alpestris and perhaps north Canadian hoyti) are potential vagrants. A candidate ‘Horned Lark’ was on the Isles of Scilly in October 2001 (Small 2002) and 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 from flava is not straightforward. Observers should pay particular attention to the precise patterning of the face, upperparts, wing coverts and underparts. Biometrics might potentially be useful.

Claims of vagrant subspecies (or a subspecies pair/group) are welcomed if accompanied by detailed notes and good photographs. Research into identification is ongoing and acceptance based on this evidence might ultimately prove to be possible but in the meantime a ringing recovery is likely to be necessary for admission to the British List. (updated Sept 2015 AMS).

References

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

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.

 

Swallow Hirundo rustica

Swallow comprises six 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 (known collectively as ‘Middle Eastern Swallow’), tytleri in southern Siberia and Mongolia and gutturalis in east Asia (known collectively as ‘East Asian Swallow’) and erythrogaster (‘American Barn Swallow’) in North America (Cramp et al. 1988). There is much individual and clinal variation, however, and genetic studies cut across the current taxonomy, identifying three major clades in Europe and western Asia, eastern Asia and North America. However, somewhat surprisingly, tytleri falls in the same clade as erythrogaster, indicating that the area around Lake Baikal may have been colonised from North America (Zink et al. 2006)

Nominate rustica is an abundant breeder in Britain but no other subspecies is on the British List. However, some are potential vagrants and birds resembling erythrogaster and transitiva have been reported in Britain (Kehoe 2006). The former 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 rustica so it is not clear how transitiva might be identified in a vagrant context. The subspecies erythrogaster is said to be more distinctive, lacking the dark breast-band in both adult and juvenile plumage but research has confirmed that tytleri may also lack a complete breast-band. Some birds from further east, attributed to gutturalis, also lack complete breast-bands. Biometrics might provide useful evidence, though erythrogaster and tytleri are similar. The subspecies gutturalis is, however, notably short-winged.

Claims of a broad subspecies group erythrogaster/tytleri/gutturalis are welcomed if accompanied by detailed notes and good photographs. Within this group, identification to subspecies level or to a tytleri/gutturalis subspecies pair would be possible based on a ringing recovery (or in the case of gutturalis on biometrics). Claims of transitiva/savignii, either separately or as a subspecies pair, should be accompanied by a ringing recovery. (updated Sept 2015 AMS).

References

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

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 two subspecies. Nominate urbicum breeds from Europe and North Africa east to western Siberia where it intergrades with lagopodum of Central and East Asia. Three other South-east Asian subspecies, formerly treated as races of House Martin, are now regarded as comprising Asian House Martin Delichon dasypus.

Nominate urbicum is a very common summer visitor to Britain. The subspecies lagopodum is not on the British list but a claim is currently in circulation.

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.

Claims of lagopodum are welcomed if accompanied by detailed notes and good photographs. (updated October 2015 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 nine subspecies, one in the Western Palearctic, four in Asia (known collectively as ‘Asian Red-rumped Swallow’) and four in Africa. Of relevance here are rufula, breeding across southern Europe, North Africa and south-west Asia, 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 (Cramp et al. 1988). 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 also 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 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 ‘Asian Red-rumped Swallow’ (i.e. daurica/japonica) are welcomed if accompanied by detailed notes and preferably good photographs. A ringing recovery might enable attribution to subspecies. (updated Sept 2015 AMS).

References

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

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.