South Sudan antelope migration also known as the Great Nile Antelope Migration (GNML) is now confirmed as the largest land mammal migration on earth. Over six million antelope species including Bohor reedbucks, Mongolla gazelles, white-eared kobs, and Tiang (Damaliscus lunatus tiang) migrate across the Greater Boma-Badingilo Migratory Landscape which includes Boma and Badingilo and Gambella national parks in South Sudan and south western Ethiopia respectively.
The migration is influenced by several factors including seasonal changes in rainfall patterns, availability of green pastures, and water and breeding. The antelopes begin their 800 km journey from Badingilo moving north to east in a semi circular direction through the Jonglei corridor, Sudd wetlands to Boma and eventually into Gambelle national park. The animals move from relatively wetter to drier areas around the White Nile and its tributaries including Sudd flooded grasslands, Kangen, Lotilla, Kinyeti Rivers which join the Pibor and Baro river that flow along the northern boundary of Gambella national park.
The Jonglei corridor which links Badingilo and Boma national parks facilitates the migration and acts as a wildlife management area. As the antelopes traverse the corridor conservationists have been able to track the migration through aerial surveys and satellite collar tracking and estimated that the population size of the Great Antelope Migration is six million, making for the world’s largest land mammal migration. According to African Parks Network, the migration includes 5 million white-eared kobs, 350,000 Mongalla gazelles, 300,000 Tiangs, and 160,000 Bohor reedbucks. Source: Wikipedia.
Boma-Badingilo Migratory Landscape
The landscape stretches for over 37,500 Sq. km including Badingilo and Boma national parks and Jonglei corridor which connects the two protected areas. The landscape was added to the UNESCO Tentative List of natural world heritage sites in 2017. The World Wildlife Fund recognizes the Boma-Badingilo Migratory Landscape among its Global 200 List of Eco-regions for biodiversity conservation. The region’s underlying soil type is black cotton soil with high content of clay soil characterized by highly alternating shrinking and expanding properties during wet and dry season. Due to the high clay content, the soil retains water which leads to seasonal flooding in the grasslands such as the Sudd and Juom Swamp wetlands.
The vegetation of the Boma-Badingilo Migratory Landscape is also influenced by the nature of soil supporting a mixture of open savanna plains and woodlands. The plains are dominated by several grass species including thatching grass (Hyparrhenia), fountain grass (Pennisetum), Barnyard grass (Echinochloa crus-galli), and Smut grass (Sporobolus indicus). The woodlands consist of Combretum molle, and Desert date (Balanites aegyptiaca). Boma-Badingilo Migratory Landscape is rich in biodiversity including mammal species such as African elephants, Nubian giraffes, Beisa Oryx, Nile Lechwe and predators like African wild dogs, northern lions, spotted hyenas, cheetahs, and caracals.
The South Sudan government through the Ministry of Wildlife Conservation and Tourism partnered with the African Parks Network under a long-term renewable agreement for the management of Boma and Badingilo national parks. The network is mandated to protect wildlife species, combat illegal poaching through effective law enforcement, and sustainable development. One of the measures to combat wildlife poaching was the formation of the joint Tiang Task Force to protect the Tiang antelope which is highly targeted for bushmeat in the Bor town.
Badingilo national park
The protected area covers 10,000 sq. km (3,900 sq mi) and is located in the Equatorial region in Southern South Sudan 22 km from Juba capital city. It was established in 1992 mainly to protect the critically endangered black rhinos, however, due to poaching and civil conflict the rhinos became extinct from the park. Badingilo serves as the breeding ground for the antelopes including Tiang and white-eared kobs given that the area is relatively wetter due to the White Nile and its tributaries which helps to provide moisture and high humidity, temperature regulation, food and protection from predators. The white-eared kob breeding season happens during the wet season between April and November. After breeding the antelopes will migrate to the drier areas in Boma and Gambella national parks.
Boma national park
The largest protected area in South Sudan is Boma national park covering an area of 22,800 sq. km (8,800 sq mi). The protected area is located in eastern South Sudan along the border with Ethiopia’s Gambella national park. Boma national park is an important habitat for the Great Nile Antelope Migration due to the relatively drier climate and a variety of habitats and water that sustains wildlife during the dry season. As a result the antelopes spend sometime and afterwards transit through to Gambella national park on their annual migration. The park is also famous for harboring endangered species including Nile lechwe, African elephants, African wild dogs, Northern African cheetah and Northern Lion. Boma is also an Important Bird Area with over 450 species of birds including the critically endangered Rüppell’s vulture (Gyps rueppelli), the bird that flies at the highest altitude of 11,300 meters above sea level where temperatures go below -54 freezing point.
Gambella national park
Gambella national park was established in 1973 and designated a BirdLife’s Important Bird and Key Biodiversity Area in 1996. The protected area is located in south western Ethiopia along the border with South Sudan’s Boma national park and is part of the larger migratory landscape. The Great Nile Antelope Migration reaches the park between February, March to June during the dry season, making for the best time to visit the park for those intending to witness the migration. Gambella is 670 km (8-hour drive) southwest of Addis Ababa and can also be reached by air via Gambella airport in Gambella town. Ethiopian Airlines offers direct scheduled flights and the park can be visited through Ethiopia safaris tour operator.
Sudd wetlands
Sudd wetlands cover an estimated 57,000 sq. km in the Nile River basin in South Sudan. The freshwater ecosystems contain permanent water sources that sustain wildlife throughout the year and serve as the feeding grounds for the Great Nile Antelope Migration during the dry season. Most of the area becomes seasonally flooded by Nile River tributaries and rainfall creating one of the world’s largest inland flooded grasslands. Sudd wetlands were designated as a wetland of international importance in 2006 due to their rich biodiversity including 8 Nile dwarf endemic fish species including Electris nanus, Cromeria nilotica, Chelaethiops bibie, Nannaethiops unitaeniatus, Epiplatys marnoi, Barbus stigmatopygus, leptura, Aplocheilichthys loati, and Andersonia. Among other rare fish communities in the Sudd wetlands include 7 Cyprinodonotids, 11 Momyrids, 31 Siluroids, 14 Cyprinoids, 16 Characoids, and 8 Cichlids. Source: UNESCO. Over 1 million people depend on the Sudd wetlands for their livelihoods among them include the fishermen and semi-nomadic pastoralists such as Dinka and Neur.
