Horned Lark, not one but six species?

José Luis Copete

Is it time to view the Shore Larks/Horned Larks with new eyes? And for UK birders did you see the bird on the Isles of Scilly in 2001..?
 

One of the passerines with a widest natural distribution in the planet is the Horned Lark (Eremophila alpestris) since it’s present in boreal and alpine habitats from five continents or subcontinents: Europe, North Africa, continental Asia, North America and South America. Its habitat requirements were a selective pressure to produce isolated populations, especially those inhabiting mountains. So, it was a case to test about its phylogeography and the resulting taxonomic implications.

Horned Lark Eremophila alpestris atlas Morocco January © Carlos Naza Bocos

Horned Lark Eremophila alpestris atlas Morocco January © Carlos Naza Bocos

Sergei Drovetski, who is working for the University of Tromsø, has been involved during recent years in analysis of the phylogeography of Holarctic species. These cases are especially convenient to be analyzed in the light of the new laboratory and computer techniques, to check whether there are separate species along the break between North America and Eurasia. He entered into the subject more than 10 years ago, studying the phylogeography of species like the Winter Wren (Troglodytes troglodytes), Pine Grosbeak (Pinicola enucleator), some grouse (Tetraonidae) and rosy-finches (genus Leucosticte), as well a first study about the Horned Lark, examining the mtDNA of one subspecies, strigata, present in British Columbia (SW Canada) and NW USA south to Oregon (Drovetski et al 2005 Streaked Horned Lark Eremophila alpestris strigata has distinct mitochondrial DNA. Conservation Genetics 6: 875–883).

 

Horned Lark Eremophila alpestris brandti Qinghai China July © Carlos Naza Bocos

Horned Lark Eremophila alpestris nigrifrons, NE Qinghai China July © Carlos Naza Bocos

Now he and colleagues expanded the range of taxa examined in the same species, sampling the birds from a very wide range, in North America, Eurasia and North Africa (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. PLoS ONE 9(1): e87570. doi:10.1371/journal.pone.0087570).

Download: >>> Eremophila <<<

 

Horned Lark Eremophila alpestris penicillata Turkey May © Carlos Naza Bocos

Horned Lark Eremophila alpestris penicillata, Turkey May © Carlos Naza Bocos

They propose a multiple split of some of the taxa present in the Palearctic, and one for North America, where pending of further study they are conservative.

The suggested splits would therefore be:

elwesi, from S & E of Tibetan Plateau

atlas, from Atlas Mts in Morocco

penicillata, from E Turkey and Caucasus E to N & W Iran

brandti, from  SE European Russia (lower R Volga) and N Transcaspia E to W Manchuria, S to N Turkmenistan, Tien Shan and Mongolia

flava, from  N Eurasia E to NE Russia (Anadyrland), S to S Norway, L Baikal and NW Amurland

and finally alpestris, for the whole of North America, pending further study, since in that continent there are around 30 different subspecies described, depending of the authorities.

Moreover, their results suggest paraphyly between Horned (alpestris) and Temminck’s (bilopha), confirming the traditional separation as two species in the birdguides.

Temminck's Lark Eremophila bilopha Morocco April © Carlos Naza Bocos

Temminck’s Lark Eremophila bilopha Morocco April © Carlos Naza Bocos

It’s expected, probably, that more species will be proposed as the study continues as there are many subspecies described for mountains of south USA and Mexico, not to mention the most isolated population in the Sierra de Santa Marta (peregrina) and nearest mountains, in NW Colombia, far away from any other subspecies.

9 thoughts on “Horned Lark, not one but six species?

  1. Peter de Knijff

    Nice, but certainly not conclusive. Any DNA study reporting a suspicious lack of congruence between the mtDNA-based phylogeographic reconstruction and the one based on “autosomal” DNA should be interpreted with great care. There are many examples of such a lack of congruence, e.g. the Lesser Whitethroat complex, the Great Grey Shrike group and the Yellow wagtail group are only a few examples, and there could be many good reasons why there is no consensus. What this shows to me is that it is too premature to impose taxonomical consequences. What it also shows is that the phylogeographic history of these species-groups is more complex than assumed, the more reason to continue studying them in even more detail. And for that, the tick-list status is irrelevant.

    Reply
  2. Ben Wielstra

    A single autosomal marker just doesn’t cut it. If it were 50 autosomal markers or so that showed no structuring I would be suspicious.

    Reply
  3. Peter

    “penicillata, from E Turkey and Caucasus E to N & W Iran”

    Also the Balkans (Bulgaria, Greece, Serbia, etc.), where Eremophila alpestris balcanica would become Eremophila penicillata balcanica under the new proposals.

    Reply
  4. Randall Moore

    What this good summary does not mention (and which bears on the question of discord between nuclear and mitochondrial results) is that the geographic variation shown by the mitochondrial gene is very highly concordant with ecological and phenotypic traits; the Eremophila groups that live in the same habitat types and those that share certain plumage characters are all more closely related according to their mtDNA. Assuming that there was no systematic bias in analysis (which is really highly unlikely with these authors), that’s powerful argument that mtDNA is doing a much better job at reconstructing phylogeny than the nuclear loci these authors investigated.

    So for my money, I’d go ahead and at least pencil in those new species….

    Reply
  5. Paul Willoughby

    Any ideas for six new common English names? Atlas Lark would be a good start. After that….?

    Reply
  6. Peter

    @ Paul Willoughby – other obvious English names include Shore Lark for flava and Horned Lark for alpestris. Trickier for the others; maybe Brandt’s Lark and Elwes’s Lark for brandti and elwesi respectively. That just leaves penicillata looking for an English name.

    Just spotted a howler in the text above though, “Moreover, their results suggest paraphyly between Horned (alpestris) and Temminck’s (bilopha), confirming the traditional separation as two species in the birdguides” – paraphyly rejects the traditional separation as two species!

    Reply
    1. Paul Willoughby

      Caucasian Lark has a ring to it, although of course it occurs beyond the Caucasus Mountains.

      Reply
  7. Brian Small

    Hi Jose Luis

    I thought I would quickly correct your distributional description for peregrina. They do not appear in the Santa Marta Mountains, but further south in the altiplano north of Bogota – largely in the Cundinamarca and Boyaca departments. Their habitat is under serious threat and I was there recently and so much of it is being degrading through agriculture and general decline in quality – erosion, etc..

    Brian

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