Blog by Simon Wotton, Senior Conservation Scientist, RSPB Centre for Conservation Science.

The Liben Plain in Oromia Province, southern Ethiopia, supports over 10,000 pastoralists with usufruct property rights and is important for agro-biodiversity, including  some 50 grass species and the unique Boran cattle. The Plain is designated an Important Bird and Biodiversity Area and is part of the South Ethiopian Highlands Endemic Bird Area and holds one of only two known populations of Liben Lark Heteromirafra archeri, the other population being near Jijiga, 600km to the north-east and in an area with significant security issues.  Poverty and drought have led to overgrazing, soil erosion, scrub encroachment, conversion of grassland to crops and severe degradation, with just 7,500 ha of degraded grassland remaining (30% of its extent 20 years ago). Consequently, the Liben Lark is listed as Critically Endangered.

Photo: A Liben Lark in the SE corner of Gamme kallo on 30th May, one of a pair foraging here. by Simon Wotton

An ambitious Darwin project ‘Sustainable management of an Ethiopian rangeland for biodiversity and pastoralists, was established on the Liben Plain in 2015, and ended in March 2019. Using participatory rangeland management, the project worked to build capacity of the local pastoralists to create more sustainable livelihoods while restoring the Liben Plain grasslands and improving the habitat for the Liben Lark, through the creation of four communally managed grassland reserves (known locally as kallos) across the Liben Plain. The kallos would be managed by pastoralist communities to provide fodder for cattle during the dry seasons, so they can produce milk during the dry season hunger gap. The project was affected by a combination of political instability, and the impacts of unusually severe drought in southern Ethiopia over two years, 2015 to 2017. After this, there was very little grass left on the Liben Plain, and many livestock perished.

Photos: The differences in vegetation height in the kallos between 2018 and 2019 was striking, as shown in the pictures above. By Simon Wotton

The June 2018 field trip found that the established kallos were full of lush grass following the best Ganna (main spring rains, roughly from February to June) on the Plain for c10 years. Unfortunately, we found far fewer Liben Larks than we hoped for on the established transect routes, with only 11 singing males or territories (as a comparison, the first organised survey here in 2007 recorded 67 on the same transects).

We repeated the survey in May and June 2019, with mixed results. There had been some rains during the Ganna, including while we were on the Plain, but not as much as in 2018.  Overall, the Plain looked badly degraded. It was quickly evident that all the kallos had fallen into disrepair since the end of the Darwin project.  We saw cattle grazing in all four kallos. In some cases, it was obvious that a lack of maintenance has caused the thornbush fencelines to blow away and create gaps. In one kallo, two large ‘gateways’ have been created to allow easy access for the cattle. It was also likely that some of the thornbush fencelines had been removed for firewood.

Photo. The cluster of Liben larks SE of Gamme kallo were mainly in an area with a high density of giant fennel Ferrula communis, a species associated with overgrazing. By Simon Wotton.

However, we did find 13 Liben Lark territories on the transect surveys compared to 10 in 2018, and through more detailed searches in the SW sector of the Plain, we managed to find more larks, with a total of 21 territories found (compared to 11 in 2018). There are two clusters of Liben Larks in the SW of the Plain, although none were found in the SE of the Plain (where there is extensive scrub encroachment).

From the vegetation monitoring, all the kallos were more heterogenous than the surrounding grassland and there was a significant difference in mean sward height inside and outside the kallos, although the mean heights were much lower than in 2018. It was also encouraging that there was a cluster of Liben Larks in and around Gamme kallo, on the W of the Plain.

To have a chance of saving the Liben Lark, we need to try to ensure that the grassland can recover where the Liben Larks were found this year, through a combination of restoring two of the kallos and trying to reduce grazing pressure here, at least during the rainy seasons. At the same time, we are now trying to understand why the kallos have not worked, through interviews with Liben Plain pastoralists, and to find a sustainable way forward for the grasslands on the Liben Plain.

The survey team for the 2019 field trip was comprised of staff from BirdLife International, RSPB and Manchester Metropolitan University. The Darwin project was funded by The Darwin Initiative, a UK government grants scheme that helps to protect biodiversity and the natural environment through locally based projects worldwide. The Darwin project partners were RSPB, the Ethiopian Wildlife & Natural History Society (the Ethiopian BirdLife partner), SOS Sahel, BirdLife International, Coventry University and Manchester Metropolitan University.

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Photos:The 21 Liben Lark territories recorded in 2019 (blue dots) in relation to the existing kallos (a) and compared to the 11 territories found in 2018 (red) and the 67 in 2007 (yellow) (b).

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