J Ornithol (2013) 154:813–825 DOI 10.1007/s10336-013-0948-1 ORIGINAL ARTICLE Rediscovery of a long-lost lark reveals the conspecificity of endangered Heteromirafra populations in the Horn of Africa Claire N. Spottiswoode • Urban Olsson • Michael S. L. Mills • Callan Cohen • Julian E. Francis • Negussie Toye • David Hoddinott • Abiy Dagne • Chris Wood • Paul F. Donald • Nigel J. Collar • Per Alstro¨m Received: 22 December 2012 / Revised: 16 February 2013 / Accepted: 7 March 2013 / Published online: 17 April 2013 Ó Dt. Ornithologen-Gesellschaft e.V. 2013 Abstract The African lark genus Heteromirafra is with the Liben (Sidamo) Lark H. sidamoensis of southern thought to consist of three threatened species inhabiting Ethiopia, but that the Horn of Africa populations are highly mid-altitude grasslands, one in South Africa and two in the distinct from Rudd’s Lark H. ruddi of South Africa. Third, Horn of Africa. One of the latter, Archer’s Lark H. archeri we suggest that the extent and quality of their habitat in of Somaliland, has not been seen with certainty since 1922. north-eastern Ethiopia is small and poor, and that the type We surveyed its type locality as well as a nearby area of locality of Archer’s Lark in Somaliland has been com- grassland east of Jijiga in adjacent north-eastern Ethiopia, pletely transformed. Taken together, these results imply where sightings of Heteromirafra larks have recently been that there is a single species of Heteromirafra in the Horn made. First, we used a combination of morphological and of Africa (for which the scientific name H. archeri has molecular evidence to show that these recent sightings priority, and which we suggest retains the English name refer to the same taxon as Archer’s Lark. Second, we used Liben Lark), consisting of two tiny populations separated a combination of morphological, molecular and vocal by 590 km of apparently unsuitable habitats. Environ- evidence to show that these populations are conspecific mental niche models suggest that there are no environ- mentally similar locations elsewhere within the region. Communicated by J. Fjeldsa˚. Despite the discovery of a second population, the Liben Lark remains a highly threatened species in urgent need of Electronic supplementary material The online version of this conservation intervention to avert the extinction of both of article (doi:10.1007/s10336-013-0948-1) contains supplementary material, which is available to authorized users. its populations. C. N. Spottiswoode (&) N. Toye Department of Zoology, University of Cambridge, PO Box 16201, Addis Ababa, Ethiopia Downing Street, Cambridge CB2 3EJ, UK e-mail: [email protected] D. Hoddinott PO Box 13972, Cascades 3202, South Africa C. N. Spottiswoode Á M. S. L. Mills Á C. Cohen DST/NRF Centre of Excellence at the Percy FitzPatrick Institute, A. Dagne University of Cape Town, Rondebosch 7700, South Africa Ethiopian Quadrants, PO Box 1201, Code 1250 Addis Ababa, Ethiopia U. Olsson Section of Systematics and Biodiversity, C. Wood Department of Zoology, University of Gothenburg, Khartoum, Sudan Box 463, SE-405 30 Go¨teborg, Sweden P. F. Donald M. S. L. Mills Á C. Cohen Conservation Science Department, RSPB, The Lodge, Birding Africa, 4 Crassula Way, Sandy, Bedfordshire SG19 2DL, UK Pinelands 7405, South Africa N. J. Collar J. E. Francis BirdLife International, Girton Road, Cambridge CB3 0NA, UK Tolpuddle Manor, Tolpuddle, Dorset DT2 7EW, UK 123 814 J Ornithol (2013) 154:813–825 Keywords African birds Á Biogeography Á Environmental Art, die dringend auf Schutzmaßnahmen angewiesen ist, da- niche Á mtDNA mit es nicht zum Aussterben beider Populationen kommt. Zusammenfassung Die Wiederentdeckung einer lange verschollenen Introduction Lerchenart belegt die Konspezifita¨t der gefa¨hrdeten Heteromirafra-Populationen am Horn von Afrika The highly distinctive lark genus Heteromirafra has a disjunct distribution in south-western and north-eastern Die afrikanische Lerchengattung Heteromirafra besteht Africa, a pattern shared with several other unrelated bird Annahmen zufolge aus drei bedrohten Arten, die Grasland genera (Cohen 2011) as well as other taxa (Lorenzen et al. in mittleren Ho¨henstufen besiedeln—eine davon in Su¨d- 2013). All three currently recognised Heteromirafra spe- afrika, die zwei anderen am Horn von Afrika. Eine der cies occur in mid-altitude grasslands: Rudd’s Lark H. ruddi beiden letzteren, die Somalispornlerche H. archeri, konnte in South Africa, Archer’s Lark H. archeri in western So- in Somaliland seit 1922 nicht mehr mit Sicherheit nac- maliland (north-western Somalia), and Liben (formerly hgewiesen werden. Wir untersuchten sowohl die Typ- Sidamo) Lark H. sidamoensis in southern Ethiopia (e.g., uslokalita¨t als auch ein benachbartes Graslandgebiet o¨stlich Ash and Miskell 1998; Ryan 2004; Collar and Stuart 1985). von Jijiga im angrenzenden Nordost-A¨ thiopien, wo ku¨rz- All three have tiny geographical ranges and are threatened lich Heteromirafra-Lerchen gesichtet wurden. Erstens with extinction: Rudd’s Lark, known from several small konnten wir durch eine Kombination aus morphologischen areas of mesic grassland in eastern South Africa, is listed as und molekularen Anhaltspunkten zeigen, dass es sich bei Vulnerable on the IUCN Red List (BirdLife International diesen neuerlichen Beobachtungen um dasselbe Taxon wie 2012b); Archer’s Lark, known with certainty only from a die Somalispornlerche handelt. Zweitens gelang es, mittels small area of arid grassland called the Wajale Plain in einer Kombination aus morphologischen, molekularen Somaliland, close to the Ethiopian border, is listed as und bioakustischen Hinweisen zu belegen, dass diese Critically Endangered (BirdLife International 2012a); and Populationen konspezifisch mit der Sidamospornlerche Liben Lark, confined to the tiny (\35 km2) Liben Plain H. sidamoensis des su¨dlichen A¨ thiopiens sind, sich die near Negele-Borana in southern Ethiopia (Fig. 1), is like- Populationen am Horn von Afrika aber deutlich von der wise Critically Endangered (BirdLife International 2012c). Transvaalspornlerche H. ruddi in Su¨dafrika unterscheiden. Archer’s Lark has not reliably been seen since June Drittens vermuten wir, dass der Lebensraum in Nordost- 1922, when Geoffrey Archer, governor of the then British A¨ thiopien von kleinem Ausmaß und schlechter Qualita¨t ist Somaliland, found seven nests on the Wajale Plain, having und dass sich die Typuslokalita¨t in Somaliland seither earlier secured at least 18 specimens (not 17 as reported) at vollsta¨ndig vera¨ndert hat. In der Summe legen diese the site in 1918–1920 (Stephenson Clarke 1920, Archer Ergebnisse nahe, dass es am Horn von Afrika nur eine and Godman 1961). The type locality has since remained einzige Heteromirafra-Art gibt (fu¨r die der wissenschaft- largely inaccessible owing to political instability, although liche Name H. archeri Priorita¨t besitzt und fu¨r die wir den 15 visits to the site or to areas adjacent to it, between 1970 englischen Namen Liben Lark (deutsch: Libenlerche) and 2008, failed to find any birds and discovered wide- vorschlagen), welche aus zwei winzigen, durch 590 km spread habitat disturbance (BirdLife International 2012a). offenbar ungeeignete Habitate getrennte Populationen However, in the last decade three separate sightings of besteht. O¨ kologische Nischenmodellierungen legen nahe, Heteromirafra larks were made ca. 50 km to the south- dass es in dieser Region nirgends Orte mit vergleichbaren west of the type locality, east of the town of Jijiga in Lebensra¨umen gibt. Trotz der Entdeckung einer zweiten neighbouring Ethiopia (by H. Shirihai, M. N. Gabremich- Population bleibt die Libenlerche eine a¨ußerst bedrohte ael, and DH & NT); the most recent bird seen (found in January 2011 by DH & NT) was photographed and con- firmed to be a Heteromirafra lark very similar in appear- P. Alstro¨m ance to Liben Lark. The same area was identified by Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, environmental niche models of the Liben population as 1 Beichen West Road, Chaoyang District, being the only other potentially suitable site in the region Beijing 100101, People’s Republic of China (Donald et al. 2010). Given the proximity of these sightings to the Wajale Plain, it appeared plausible that this popu- P. Alstro¨m Swedish Species Information Centre, lation might be conspecific with Archer’s Lark. Swedish University of Agricultural Sciences, In addition to uncertainty about its persistence and Box 7007, SE-750 07 Uppsala, Sweden geographical range, the taxonomic status of Archer’s Lark 123 J Ornithol (2013) 154:813–825 815 to Djibouti, 290 km Boorama YEMEN SUDAN SOMALI- ETHIOPIA LAND Jijiga/Wajale Liben Plains OMALIA S Gebilay 15 km transects, 29–30 May 2010: to Hargeisa, 0 birds 50 km Tog Wajale SOMALILAND 7 km transect, 12 May 2011: 1 bird 7 km transect, 11 May 2011: Jijiga 14 birds to Addis ETHIOPIA Ababa, 760 km 10 km to Gode, 540 km Fig. 1 Current and historical distribution of Heteromirafra larks in north-eastern Ethiopia and Somaliland has long deserved thorough inquiry, as it is morpholog- opportunity to reassess both the taxonomic and conser- ically very similar to both other Heteromirafra species vation status of Liben and Archer’s Larks in the light of and its song was never recorded or described. In partic- new data. ular, the possibility that it is conspecific with Liben Lark In this paper we address three questions. First, does the needed to be assessed. The two species both occur (or recently discovered population of Heteromirafra larks at occurred) in seasonal grassland, separated by 630 km of Jijiga belong to the same taxon as Archer’s Lark? We what is assumed to be unsuitable habitat (largely desert address this using analyses of mitochondrial DNA extrac- and high mountains). However, climatic conditions in the ted from two live birds we captured at Jijiga, and toe-pad Horn of Africa were considerably wetter in the early samples from historical specimens of Archer’s Lark col- Holocene, with two periods of aridification occurring lected at the type locality.