|Scientific Name:||Heteromirafra sidamoensis|
|Species Authority:||Erard, 1975|
|Red List Category & Criteria:||Critically Endangered B1ab(ii,iii,v);C2a(ii) ver 3.1|
|Reviewer/s:||Butchart, S. & Taylor, J.|
|Contributor/s:||Borghesio, L., Collar, N., Donald, P., Fishpool, L., Mwangi, K., Ndang'ang'a, P., Sinclair, I., Spottiswoode, C. & Wondafrash, M.|
This species is listed as Critically Endangered because it has an extremely small range, it is only confirmed to occur at a single location and its range size is decreasing. Remaining habitat is rapidly being degraded, and the number of mature individuals is decreasing (the total population is now believed to number fewer than 250 mature individuals). A potentially skewed sex ratio may mean the effective population size is even smaller, and there is a very real possibility that the species will become extinct in the next two to three years.
|Range Description:||Heteromirafra sidamoensis was for some time known only from two specimens collected at adjacent sites near Negele in the former Sidamo province (now Guji Zone), southern Ethiopia, in May 1968 and April 1974. Since 1994 there have been subsequent sightings of small numbers (<10 on each occasion) in the Negele area. Analysis of these locations on satellite images and recent fieldwork suggests that the species is restricted to a very specific habitat (tall-grass prairie) in the calcareous plateau east and south of Negele (L. Borghesio in litt. 2005, Donald et al. 2010). Between 1973 and 2002 the area of tall-grass prairie decreased by about 30%, and in 2003 much of it was being rapidly encroached by agriculture and shrubs (Acacia drepanolobium and others) that are probably favoured by excessive grazing pressure and the suppression of seasonal fires (L. Borghesio in litt. 2005). Remaining grassland is being heavily degraded by overgrazing (Spottiswoode et al. 2009). By 2007-2008 it appeared to be restricted to a single grassland patch 30-36 km2 in area, and the global population was estimated at just 90-256 mature individuals, with the effective population size perhaps even smaller owing to a potentially skewed sex ratio caused by predation of females on the nest (Spottiswoode et al. 2009). Results of survey work to date indicate that the species has fewer than 100 territories (the number of pairs is unknown: females seem to be much scarcer than males, so many territories may be held by bachelors) (Donald et al. 2010, N. Collar in litt. 2011). Compared with a survey in June 2007, fieldwork in May 2009 recorded a decline of 40% in the number of birds present along repeated transects and a contraction of 38% in the area of the Liben Plain occupied by the species (Donald et al. 2010). Predictive modelling based on the characteristics of the Liben Plain suggests that apart from a smaller and highly politically unstable area c.500 km to the north-east near the Somalian border, there is no other suitable habitat for the species within the Horn of Africa (Donald et al. 2010). The prediction of suitable habitat in eastern Ethiopia is remarkable because the area is adjacent to the type locality of Heteromirafra archeri (not seen since 1922) and is just 30 km from two fairly recent sightings of unidentified Heteromirafra larks. It is very possible that the two taxa will prove to be conspecific, but the area is likely to remain inaccessible for some time owing to extreme political instability, during which time any remaining population of Heteromirafra larks may well become extirpated (Donald et al. 2010). Thus the focus remains on the Liben Plains as the sole known location for the species (Donald et al. 2010), and without urgent and concerted intervention global extinction is likely within the next few years (Spottiswoode et al. 2009).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The total range appears to be a single grassland patch just 30-36 km2 in area, and its population density is an order of magnitude lower than previously suspected, inferring a global population of 90-256 mature individuals, roughly equivalent to 130-390 individuals in total.|
|Habitat and Ecology:||
All reliable records appear to fall within or near grassland areas (L. Borghesio in litt. 2005). A possible sighting in 1971 in dense Acacia woodland seems doubtful (L. Borghesio in litt. 2005). It has been found to avoid woody vegetation, very short grass and bare ground (all symptomatic of degraded rangelands), and to favour a grass sward of intermediate height (5-15 cm) (Spottiswoode et al. 2009). It has never been recorded from croplands (Spottiswoode et al. 2009). The nest is a grass bowl on the ground (Collar et al. 2008).
The Negele plateau is being degraded by human activities, leading to loss of grassland habitat and encroachment of bush, mainly Acacia drepanolobium (Coppock 1994; M. Wondafrash in litt. 2005). Shrub encroachment has probably been exacerbated by the fire suppression that has been enforced in the area since the 1980s (L. Borghesio in litt. 2007). Refugees from drought-stricken and tribal conflict areas are augmenting the dense local human population, and nomadic pastoralism is giving way to permanent cultivation, which is the principal threat to the species (M. Wondafrash in litt. 2005). A watering point has been developed in the core of the species's range, leading to concentrations of livestock and consequent disturbance, overgrazing and trampling (M. Wondafrash in litt. 2005). Remaining grassland had become even more degraded between the 2007 and 2008 surveys, leaving no real cover for the species, and potentially leading to high predation of females on the nest, reducing breeding success to zero and further lowering the effective population size (N. J. Collar in litt. 2009). Further fieldwork in 2009 confirmed that habitat degradation was continuing, probably due to overgrazing, and that grassland was still being lost to cultivation (Donald et al. 2010). Between 2010 and 2011, around a third of the grassland on the northern side of the Liben Plain was lost to agriculture (P. F. Donald in litt, 2012). The operation of a military training area (near the Bogol Manya crossroads) was previously listed as a potential threat (I. Sinclair in litt. 1999), but this had been abandoned by July 2005 (L. Fishpool in litt. 2006). Drought, such as that ongoing in the Horn of Africa in 2011, may compound these threats, and rising temperatues may pose a pose a longer-term threat to the survival of the species.
Conservation Actions Underway
Fieldwork has been taking place since 2007 to investigate the species's status (M. Wondafrash in litt. 2007; Donald et al. 2010). A workshop in 2009 involving key stakeholders resulted in the creation of an intersectoral committee to manage the restoration of the Liben Plain, an agreement to oppose any further agricultural expansion and a willingness to work with conservation organisations to preserve pastoralism (N. J. Collar in litt. 2009), and further stakeholder meetings have taken place since. Work to clear scrub, establish non-grazing areas and prevent of further conversion of grassland on the plain is imminent, and capacity-building work training young Ethiopian nationals is ongoing (N. J. Collar in litt. 2011). Conservation Actions Proposed
Conduct further surveys (during the breeding season, when birds are likely to be singing and hence most conspicuous) throughout the Negele Plateau to establish its range and population, and determine whether there is a significantly biased sex ratio. Investigate the causes of bush encroachment in the area (L. Borghesio in litt. 2007). Undertake detailed socioeconomic research to identify the drivers of grassland conversion. Urgently determine the most appropriate means to safeguard areas of suitable habitat from further degradation and disturbance. Identify key areas where livestock and disturbance can be kept to a minimum and the natural fire regime is maintained. Raise awareness of the local communities and authorities of this important endemic taxon. Investigate the use of exclosures to eliminate grazing from some areas of the Liben Plain, and the possible need to employ ploughing and re-sowing of local grass species to restore suitable habitat(Donald et al. 2010). Clear encroaching Acacia thorn scrub from parts of the Liben Plain (Donald et al. 2010). Assess the possibility of using hyena dung to create small ungrazed areas with suitable nesting cover. Clarify taxonomy of Heteromirafra at Jijiga, and assess range, population size, trend and threats there.
Collar, N. J.; Abebe, Y. D.; Fishpool, L. D. C.; Gabremichael, M. N.; Spottiswoode, C. N.; Wondafrash, M. 2008. Type locality, habitat, behaviour, voice, nest, eggs and plight of the Sidamo Lark Heteromirafra sidamoensis. Bulletin of the African Bird Club 15(2): 180-190.
Collar, N. J.; Stuart, S. N. 1985. Threatened birds of Africa and related islands: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, and International Union for Conservation of Nature and Natural Resources, Cambridge, U.K.
Coppock, D.L. 1994. International Livestock Centre for Africa, Addis Ababa, Ethiopia.
Donald, P. F.; Buchanan, G. M.; Collar, N. J.; Abebe, Y. D.; Gabremichael, M. N.; Mwangi, M. A. K.; Ndang'ang'a, P. K.; Spottiswoode, C. N.; Wondafrash, M. 2010. Rapid declines in habitat quality and population size of the Liben (Sidamo) Lark Heteromirafra sidamoensis necessitate immediate conservation action. Bird Conservation International 20(1): 1-12.
EWNHS. 1996. Important Bird Areas of Ethiopia: a first inventory. Ethiopian Wildlife and Natural History Society, Addis Ababa.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
Robertson, I. S. 1995. First field observations on the Sidamo Lark Heteromirafra sidamoensis. Bulletin of the British Ornithologists' Club 115: 241-243.
Spottiswoode, C. N.; Wondafrash, M.; Gabremichael, M. N.; Abebe, Y. D.; Mwangi, M. A. K.; Collar, N. J.; Dolman, P. M. 2009. Rangeland degradation is poised to cause Africa's first recorded avian extinction. Animal Conservation 12(3): 249-257.
|Citation:||BirdLife International 2012. Heteromirafra sidamoensis. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 19 June 2013.|
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