About the project
In Ethiopia, Eurasian Cranes Grus grus and Demoiselle Cranes Anthropoides virgo are winter visitors, while the elegant Black-Crowned Cranes Balearica pavonina and the large Wattled Cranes Bugeranus carunculatus are sedentary and also breed in this east African country. As there is little information available about the size and the threats of the different crane populations, a joint project between Crane Conservation Germany, the working group “Africa” of the German Nature And Biodiversity Conservation Union (NABU, BAG Africa) and the Ethiopian Wildlife and Natural History Society (EWNHS) was started in 2007 to monitor the numbers as well as to learn more about the population development and threats of crane populations in Ethiopia.
During the first three expeditions in the years 2007, 2009 and 2011, altogether three to four teams found several previously unknown wintering areas of the Eurasian Cranes, but found also breeding and gathering places of the African crane species. In 2013 two teams controlled all known wintering sites from 17th to 28th January, but also searched for new roost sites. These sites were identified with satellite and aerial images from Google Earth and were later verified in the field with the help of gps devises.
Achieved results
During the monitoring in 2013, altogether 67,150 Common Cranes, 1,771 Black-Crowned Cranes (1,074 in 2011) and 104 Wattled Cranes (157 in 2011) were counted. With the exception of the Demoiselle Crane, largest concentrations were found in shallow waters in the Rift valley and around lake Tana.
Dramatic structural changes were already detected during the road trip to Debre Zeyt and in the near surroundings. Along the motorway several new trade and production facilities of foreign investors were built, but also new greenhouses, chicken farms and strawberry plantations. Most of the manufactured products are exported. Consequently the heavy goods vehicle traffic has been multiplied in the last six years.
Dramatic changes we detected at Chelekleka Chefe wetland, one of the most important crane roosts in Ethiopia. On the 4th of February 2009 more than 17,000 Eurasian Cranes used that roost site. During the monitoring of the mourning flight on 30th of January 2011, only 250 cranes used that site. Right across that nearly completely drained wetland, a new asphalt road to Addis Abeba was constructed. We were quite surprised about the 12,000 Eurasian Cranes which we counted in the early morning of the 18th January 2013 at this site. But already during another count only ten days after, most of the water was pumped away for the ongoing road construction. In that situation only 2,700 cranes remained at this roost site.
Also the construction of huge plastic greenhouses in the direct neighborhood of wetlands, like near the Koka reservoir and around Lake Ziway, has a negative impact on crane habitats. Here the water is pumped away for the production of cut flowers, which results in rapide decreases of water levels in these wetlands. Most of these cut flowers are exported to Israel and Germany. Similar greenhouse constructions are found in other places as well, like around Lake Tana.
Our worst expectations became true after visiting Akaki wetland. During a visit on 31st of January 2011 9,150 Eurasian Cranes, thousands of Greater and Lesser Flamingos, different species of herons and many other waterbirds were counted in the shallow Lake Akaki. But during another visit only 14 days later, the wetland was nearly completely drained and the cranes deserted that roost site. In the year 2013, the situation became even worse. Nearly the complete are was transformed into agricultural land and used intensively with the help of modern tractors. The drainage of wetlands is used for the reclamation of new land for the steadily increasing agrarian industry. The speed with which these areas, formerly used for traditional and small scale farming, are transformed into species-poor industrial agrarian landscapes is frightening.
At those roost sites, more or less untouched by infrastructural changes, we monitored only slight changes in the crane populations. However, we found mobile water pumps for the irrigation of fields several times, which can lead to a decrease of water levels after pumping. At the roost site Cheleklekka Ziway, the water level was much lower in comparison to previous years. During a count on 20th of January 2013 we only found 2,800 Eurasian cranes, which are significantly less than the 3,500 cranes, which we counted on 3rd of February 2011.
On 2nd of February 2011, we fortunately discovered the formerly undescribed Chuche wetland south of Butajira. Here not only 840 Eurasian Cranes, but also 54 of the highly threatened Wattled Cranes were found. According to C.D. Meine and G.W. Archibald 1996 (Status Survey and Conservation Crane Action Plan of IUCN „The Cranes“), only a few hundred individuals of this large African crane species exist in Ethiopia. Despite intensive search, unfortunately only 22 Wattled Cranes remained at this site during another survey on 26th of January 2013.
In general, only very few juvenile birds of Black-crowned Cranes and Wattled Cranes were observed during our surveys. Main reasons for the loss of clutches or chicks are strong disturbances due to intensive use of wetlands and the related loss of aquatic plants, but also direct losses by humans and straying dogs.
Beside the wellknown roost site near Shesher at the eastern shore of Lake Tana, a new roost site was discovered at the northern part of that lake, at the mouth of the River Megech. This area, which is largely flooded with extensive zones of shallow water, is difficult to access and has a huge importance for breeding and resting birds. In January 2013, about roosting 12,000 Eurasian Cranes were counted here.
As described also from other areas, the situation for cranes at Lake Tana is alarming. Numerous cranes are killed after collisions with the new high-voltage powerlines, which were constructed in the course of the development of new hydroelectric power plants in the region.
We got also reports, that Chinese workers illegally hunt for birds and collect bird eggs, or buy hunted birds from local Ethiopians, among them also cranes. There is a real danger, that a new “market” for wild bird meat is developing, which will have very negative influences on the Ethiopian avifauna.
For the first time we also found a dead crane, hanging on a wooden trunk, which was obviously placed by a local farmer to scare away other cranes. This might by also a consequence of the increasing pressure to farmers, which have less land available for their farming.
Future perspectives
The large scale conversion of wetlands into farmland and industrial areas, stimulated by foreign investors, are a major threat especially for the Wattled Cranes. But also local people, replaced by the industrial development, resettle and increase the human pressure to the remaining wetlands.
The use of the results of the crane monitoring in the land use planning of the Ethiopian government is urgently needed to create a balance between economic interests and ecological issues. Some of the core areas for the Wattled Cranes are now known, which is the basis for further activities to designate protected areas for the cranes in their key areas.
For the Black-Crowned Crane, knowledge gaps on the habitat use throughout the year, especially for juvenile birds, still exist. This knowledge is needed to give recommendations, how to design protected areas for this species.
Fortunately, a memorandum of understanding between Crane Conservation Germany, the working group “Africa” of the German Nature and Biodiversity Conservation Union (NABU, BAG Africa) and the University of Jimma was signed in November 2013 to improve the conservation of the cranes in Ethiopia. In a first step within the framework of this MoU, the scientists Dessalegn Obsi Gemeda and Tariku Gutema were invited to Germany to participate in a training workshop in June and July 2014, organized by Crane Conservation Germany. Here they were trained how to catch, ring and tag wild cranes.
This knowledge will be used in the future to catch and individually mark cranes also in Ethiopia. This will help to gather data about the annual migration patterns and habitat requirements of Black-Crowned and Wattled Cranes in their breeding, staging and wintering areas. The expected results will provide important information for the conservation of the two threatened African crane species.
Acknowledgement
We want to thank very much the following institutions and persons for their support during planning the expeditions or during field work: Mengistu Wondafrash (EWNHS), Tariku Gutema (university of Jimma), Yilma Dellelegn (EWNHS), Shimelis Aynalem (university of Bahir Dar), Mihiret Ewnetu (Wildlife Department of MoARD), Chere Enawgaw (Wildlife Department of MoARD), Berihu Gebremedhin (IBC), Tewabe Ashenafi (EWNHS), Endale Wolde Tensai (EWNHS), Hassen Yussuf Kaariye (AL WABRA Dibatag research project), Friedrich Wilhelmi (NABU/Al WABRA Dibatag research project), Itai Shanni (IOC, Israel), Carl-Albrecht von Treuenfels (CCG, Germany, ICF), Hartwig Prange (CCG, Germany). Special thanks also go to the Lufthansa Group for their additional support.