Heteromirafra sidamoensis
| Kingdom |
Phylum |
Class |
Order |
Family |
| ANIMALIA |
CHORDATA |
AVES |
PASSERIFORMES |
ALAUDIDAE |
| Scientific Name: |
Heteromirafra sidamoensis |
| Species Authority: |
Erard, 1975 |
Common Name/s:
| English |
– |
Liben Lark, Sidamo Bushlark, Sidamo Lark, Sidamo Long-clawed Lark |
| French |
– |
Alouette d'Erard |
|
Assessment Information
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| Red List Category & Criteria: |
Critically Endangered
B1ab(ii,iii,v);C2a(ii)
ver 3.1
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| Year Published: |
2010 |
| Assessor/s: |
BirdLife International |
| Reviewer/s: |
Calvert, R., Symes, A., Butchart, S. |
| Contributor/s: |
Spottiswoode, C., Wondafrash, M., Mwangi, K., Ndang'ang'a, P., Borghesio, L., Fishpool, L., Collar, N., Sinclair, I. |
Justification:
This species is listed as Critically Endangered it has an extremely small range, it is confined to 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.
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| History: |
| 2009 |
– |
Critically Endangered
|
| 2008 |
– |
Endangered
|
| 2007 |
– |
Endangered
|
| 2004 |
– |
Vulnerable
|
| 2000 |
– |
Vulnerable
|
| 1996 |
– |
Endangered
|
| 1994 |
– |
Endangered
|
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Geographic Range
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| 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 Negele4. 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 fires4. Remaining grassland is being heavily degraded by overgrazing12. 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 nest12. 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 species14. Without urgent and concerted intervention global extinction is likely within the next few years12.
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| Countries: |
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| Range Map: |
Click here to open the map viewer and explore range.
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Population
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| 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 (Spottiswoode ei al 2009).
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| Population Trend: |
Decreasing
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Habitat and Ecology
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| Habitat and Ecology: |
All reliable records appear to fall within or near grassland areas4. Recent sightings have been in grassland with a few scattered Acacia bushes2. A possible sighting in 1971 in dense Acacia woodland seems doubtful4. 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)12. It has never been recorded from croplands12.
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| Systems: |
Terrestrial |
| Major Threat(s): |
The Negele plateau is being degraded by human activities, leading to loss of grassland habitat and encroachment of bush, mainly Acacia drepanolobium5,6. Shrub encroachment has probably been exacerbated by the fire suppression that has been enforced in the area since the 1980s10. 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 species6. A watering point has been developed in the core of the species's range, leading to concentrations of livestock and consequent disturbance, overgrazing and trampling6. 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 size13. Further fieldwork in 2009 confirmed that habitat degradation was continuing, probably due to overgrazing, and that grassland was still being lost to cultivation14. The operation of a military training area (near the Bogol Manya crossroads) was previously listed as a potential threat3, but this had been abandoned by July 20058.
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Conservation Actions
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| Conservation Actions: |
Conservation Actions Underway
Fieldwork took place in 2007-2009 to investigate the species's status11,14. 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 pastoralism13.
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 area10. 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 habitat14. Clear encroaching Acacia thorn scrub from parts of the Liben Plain14.
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