The Horned Lark (Eremophila alpestris), has one of the widest natural distributions of any bird in the Passeriformes order on the planet. Its range spans across Europe, North Africa, continental Asia, North America and South America in boreal & alpine habitats, has resulted in at least 40 subspecies being recognised. The reason for the sheer number of subspecies is due to the species habitat requirements, which over time resulted in the selective pressure to produce isolated populations, best demonstrated in populations located in mountain regions: Southern Horned Lark (E. a. penicillata), Steppe Horned Lark (E. a. brandti) & Moroccan Horned Lark (E. a. atlas) etc.
Sergei Drovetski of the University of Tromsø, has for some time been involved in the analysis of the phylogeography of Holarctic species. Over the last few years he and his team conducted the first study of Horned Lark (Eremophila alpestris) produced the paper “Drovetski et al 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” – You can download his paper by clicking on the link, Birding Frontiers: Horned Lark, not one but six species?
The paper proposes a multiple split of some of the taxa present in the Palearctic, and one for North America, where pending of further study.
The proposed splits are:
- elwesi – S & E of Tibetan Plateau.
- atlas – Atlas mountains in Morocco.
- penicillata – E Turkey and Caucasus E to N & W Iran.
- brandti – SE European Russia (lower R Volga), N Transcaspia E to W Manchuria, S to N Turkmenistan, Tien Shan and Mongolia.
- flava – N Eurasia E to NE Russia (Anadyrland), S to S Norway, L Baikal and NW Amurland.
- alpestris – Whole of North America, however pending further study given 30 different described subspecies described, depending of the authorities.
In late November 2017, it came to light that a Horned Lark which had been present for several weeks around the Staines reservoir complex, Surrey, was in-fact not your typical flava (Shore), the only subspecies which is on the British List. The lark had been re-identified several weeks later, having been reported as a flava, to one of the Nearctic forms, either alpestris (eastern Canada) or hoyti (central Canada). Both races are one of the longer distance migrants of the Nearctic forms with no reason why either race could not be a potential vagrant to Western Pelearctic.
As it stands no Nearctic form is on the British List thus, if accepted then this would be a first for Britain. There have however been previous candidates of ‘American Horned Lark’ in Britain & Ireland, but not accepted – Isles of Scilly (2001), South Uist (2014) and Co.Down (1998).
Given my recent fixation on avian taxonomy, I had to make a visit to connect with this Nearctic lark. If my memory serves me right, then this is only my second Nearctic passerine, first being Buff-bellied Pipit on Burton Marsh, Cheshire back in 2013, my first twitch!
On arrival I just missed NGB Samuel Levy, however the lark showed brilliantly, lucky enough to have it call several times, along with a good supporting cast of a Great Scaup, Red Kite (A scarce bird in Wirral & Cheshire), pulse a stonking summer plumage Black-necked Grebe; all three additions to my year list (145) including Ring-necked Parakeet which shot over the station whilst waiting for my return back to London.
As I had two hours to burn before my train was due to depart, I had a scout around the capital; highlight was certainly the sheer quantity of sinensis Great Cormorant, at least 50 where along the mile or so of the Thames I walked along.
Rounding off the trip was a brief visit to St. Jame’s Park, only so I could have a look and see if there were any colour ringed birds knocking about and sure enough there was: Eurasian Coot (6) and just a single Black-headed Gull. It was leaving to catch my train back that I did get a rather big surprise as one of the seemingly ‘captive’ Great White Pelicans was in-fact flying freely around the park, which made for one hell of a sight before my departure!
Thanks for reading,