Taxonomic status of ‘long-billed’ Crested Larks at Aousserd?

To which taxa belong the ‘crested larks’ observed in the Aousserd region and in the adjacent area of northern Mauritania? First, which species: Maghreb Lark or Crested Lark sensu stricto? And also, which subspecies exactly?

À quels taxons appartiennent les «cochevis huppées» observées dans la région d’Aousserd et dans le nord de la Mauritanie ? D’abord, quelle espèce : Cochevis à long bec (appelée aussi Cochevis du Maghreb) ou Cochevis huppée sensu stricto ? Et aussi, quelle sous-espèce exactement ?

Based on the study of Guillaumet et al. (2005, 2006 and 2008), the ‘IOC World Bird List’ split Maghreb Lark (Galerida macrorhyncha) from Crested Lark (Galerida cristata) in 2009.

Two subspecies of Maghreb Lark are known: macrorhyncha in south-east Morocco and north-west Algeria south of the Saharan Atlas, and randonii in Hauts Plateaux of eastern Morocco and the adjacent part of western Algeria. “WC Mauritania (Atar area)” is also added to the distribution range of the macrorhyncha by both the ‘IOC Checklist’ and the ‘HBW Alive’. (Presumably because the birds in this area are also “long-billed”).

Are birds from Atar truly belong to macrorhyncha or not?

The single Mauritanian sample used in the study of Guillaumet et al. (2006, 2008) was most likely from or near Atar (where the local “crested lark” is traditionally treated as macrorhyncha as mentioned above). However, the genetics tells a different story: the haplotype of that sample belong to the senegallensis group of the Crested Lark sensu stricto (this group includes birds from eastern Algeria, Tunisia and western Sahel). In general, the larks in this group have bills of intermediate length (at least birds from Tunisia). There is however some variation with some birds having shorter bills similar to G. cristata while others having longer bills similar to G. macrorhyncha (Guillaumet et al. 2006). The isolated populations in the Sahara or south of the Sahara (Sahel) are characterized by shorter size and bill (Guillaumet et al. 2006, samples for the morphometry in this study were from Senegal, Mali and Chad but not from Mauritania).

All these raises, inevitably, two questions:

1. Are all the birds in Atar area have longer bills or is there some variation as in the case of the birds in Tunisia? and most importantly,
2. Why these birds are considered to belong to macrorhyncha despite the fact that the only genetic sample from that area is shown to belong to the senegallensis group?

On the other hand, Crested Larks on the coastal area of northern Mauritania (subspecies balsaci, which belong to the senegallensis group) have longer bills (but still shorter than in typical macrorhyncha found in the core area known to birders who visit Morocco – between Merzouga and Ouarzazate).

Some photographs:

• Photos of Crested Larks of the senegallensis group (subspecies balsaci?) taken at Nouakchott, Mauritania, in January 2017 by Robert Tovey.
• Photos of Crested Larks of the senegallensis group taken at Ndiaël, northern Senegal, in January 2016 by Frédéric Bacuez (the last five photos).
• Here are a few examples of Maghreb Larks from Morocco as well: at Mhamid, at the edge of Ouarzazate and at Rissani.

Galerida larks at Aousserd and Oued Dahab in general:

Here is a summary of the current knowledge about the distribution of Galerida larks in Oued Dahab based on the data compiled in Bergier et al. (2017):

• Thekla’s Lark (G. theklae): breeds along a narrow area along the coast, more discontinuous south of Dakhla. No confirmed records deep inland (e.g. around Aousserd).
• Crested Lark sensu stricto: only isolated records along the coast. However, the authors added “to date, there is no capture or incontestable photographic documentation of “short-billed” Crested Lark in the Atlantic Sahara”. There are no data on the interior of Oued Dahab (i.e. that includes also Aousserd).
• Maghreb Lark: no confirmed records in the whole Oued Dahab (and further north as well).

Identification challenge

Swedish photographer Lars Petersson took the photos below near the town of Aousserd in January 2018. Because neither Crested Lark nor Maghreb Lark are known to occur in that area, as mentioned above, Lars sent me the photos and asked my opinion about their ID.

The birds are not Thekla’s Larks as the long bills alone will exclude this species. At the same time, the bills are too short for the typical Maghreb Lark (G. m. macrorhyncha).

When I saw the photos, here is my thought: “the bird on the rock looked good for Maghreb Lark, but I am not 100% sure for the other bird on the ground”. I asked two colleagues, B. M. and J. F., and they basically said the same thing “the bill seemed long enough for the Maghreb Lark, especially the bird on the rock”.

When asked about his opinion, Pierre-André Crochet said: “Difficult … it’s not a Thekla’s Lark (bill too long, bird structure, color). But after that, between Crested Lark sensu stricto and Maghreb Lark it’s difficult in the photos…. In addition there is the ‘senegallensis’ clade (present just to the south in Mauritania) which has a long bill, but of which I do not have photos… Knowing that in Aousserd we find a lot of Sahelian fauna, nothing prevents these birds from being from the senegallensis group”.

Any idea or comment is welcome. And of course any photos of Galerida larks is that area are welcome as well.

References:

Bergier, P., Thévenot, M. & Qninba, A. 2017. Oiseaux du Sahara Atlantique Marocain. SEOF, Paris, 359 pp.

de Juana, E. & Suárez, F. 2018. Crested Lark (Galerida cristata). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/57674 on 7 February 2018).

Gill, F. & Donsker, D. (Eds). 2018. IOC World Bird List (v8.1). doi: 10.14344/IOC.ML.8.1. www.worldbirdnames.org [Accessed 07 February 2018].

Guillaumet, A., Crochet, P.-A. & Godelle, B. 2005. Phenotypic variation in Galerida larks in Morocco: the role of history and natural selection. Molecular Ecology 14: 3809–3821.

Guillaumet, A., Pons, J.-M., Godelle, B. & Crochet, P.-A. 2006. History of the Crested Lark in the Mediterranean region as revealed by mtDNA sequences and morphology. Molecular Phylogenetics and Evolution 39: 645–656.

Guillaumet, A., Crochet, P.-A. & Pons, J.-M. 2008. Climate-driven diversification in two widespread Galerida larks. BMC Evolutionary Biology 8: 32.

Updates:

Both Michel Thévenot and Patrick Bergier agreed with P. A. Crochet who leans towards considering these larks as Crested Lark of the ‘senegallensis‘ group. Here are the quotes from their detailed responses:

M. Thévenot:

Je suis assez d’accord avec P.A. Crochet qui penche pour faire des oiseaux d’Aousserd plutôt des Cochevis huppé du groupe senegallensis que des Cochevis à long bec au vu de leur morphologie (taille du bec, etc…) et de la répartition géographique respective connue des deux espèces.

P. Bergier:

L’oiseau photographié par Lars me semble très proche des ‘senegallensis‘ de Frédéric Bacuez. La présence de quelques senegallensis (ou proches de senegallensis) à Aousserd ne serait finalement pas très étonnante, sachant qu’il semble commun à Atar qui n’est distant que de 250 km environ.

See more information about the Crested Lark in Mauritania in the link in Frédéric’s comment below.

Arnoud B. van den Berg uses the name ‘short-billed’ Maghreb Lark to describe these birds. See just below the first photo here: ‘Birding and sound recording trip to Oued Dahab region by The Sound Approach‘.

Any photographs or additional information from the region are much appreciated. Thanks!