Searching for the critically endangered Liben lark

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

I'm just back from the Liben plains in southern Ethiopia, where I joined a survey looking for Liben larks, Heteromirafra archeri.

Why are we surveying Liben larks?

An ambitious Darwin project was established on the Liben plains in 2015. Using participatory rangeland management (PRM), this innovative project will work to build capacity of local people to create, and support the creation of more sustainable livelihoods while restoring the Liben grasslands and improving the habitat for the Liben lark, through the creation of (so far) four communally managed grassland reserves (‘kallos’) across the plain.

A Liben Lark, image by Paul Donald

The kallos will be managed by pastoralist communities to provide fodder for cattle, so they can produce milk during the dry season hunger gap.

The Liben Plain supports c.10,000 pastoralists with usufruct property rights. Designated an Important Bird and Biodiversity Area and part of the South Ethiopian Highlands Endemic Bird Area, the Plain holds one of only two populations of Liben lark , and important agro-biodiversity (a strategic priority in Ethiopia’s NBSAP), including c50 grass species and the unique Boran cattle.

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.

Encroaching scrub on the eastern side of the Plain.  There is considerable evidence that Liben Larks won’t nest close to bushes or trees, most likely due to predation risk.

The project was due to finish in March 2018, but has been given an extension until September due to a combination of political instability, from October 2016, when a state of emergency was declared, and the impacts of unusually severe drought in Ethiopia.

There was drought in 2015/16, due to an extremely severe El Niño weather pattern, and the rains failed in southern Ethiopia in 2016/17, leading to a severe humanitarian crisis. After this, there was very little grass left on the Liben Plain, and many livestock perished. This drought, as well as the State of Emergency and political turmoil, led to an influx of new pastoralists to Liben and conflict over grazing resources, which has put more pressure on the Plain.

One of the requirements of the Darwin project was to monitor the Liben lark population and the enclosures (known locally as kallos) that were created on the plain to provide additional fodder for livestock during the dry seasons and more suitable habitat for the larks.

The monitoring has had to be postponed a number of times due to the political instability and drought conditions, but we realised there was a short window of opportunity to carry out a survey in June 2018.

Our first view of the Plain, with the grass looking very green but short.

What we found

The field trip found that the four kallos that have been established are full of lush grass following the best rains on the Plain for c10 years earlier this year, from February to June.

Unfortunately, we found far fewer Liben larks than we hoped for on the established transect routes. There were only 10 singing males/territories found (as a comparison, the first organised survey here in 2007 recorded 67 on the same transects).

An encouraging additional record was of a pair feeding near-fledged young in the corner of the Gamme kallo, although these were our only records in the kallos.

Much of the rest of the plain shows signs of overgrazing and continued degradation, with more land converted to crops and increasing scrub encroachment. We did find good numbers of other species, including Somali short-toed larks and kori bustards and an abundance of invertebrates within the kallos.

There is a very high density of Kori bustards (the world’s heaviest flying bird) on the Liben Plain. Here two males were involved in a very coordinated display!

What does this mean?

We are very concerned that we found so few Liben larks. It is quite likely that the two years of drought have had a severe impact on the population.

We are remaining hopeful that the breeding season may have started early this year, as the rains started in February, and non-breeding birds may have been missed. Liben larks are notoriously difficult to pick up if they’re not singing and/or nesting.

Two new kallos will be established this summer, and these will be located in two of the areas where we had Liben lark activity this year. It is crucial that we can return in May/June next year to find out if the Liben larks have started to recover and if the kallos are working.

Partners

The Darwin project partners are the RSPB, the Ethiopian Wildlife & Natural History Society (the Ethiopian BirdLife partner), SOS Sahel, BirdLife International, Coventry University and Manchester Metropolitan University. The June field survey team consisted of Yilma Abebe (EWNHS), Nigel Collar (BirdLife International), Abiy Dagne (Ehtiopian bird guide & tour operator), Dan Gornall (Manchester Metropolitan University), Mercy Kariuki (BirdLife International), Wario Sara (EWNHS) and myself.