Seen from the sky, they undulate across the landscape - a river of antelope crossing South Sudan's vast grasslands in what conservationists say is the world's largest migration of land mammals.
The first comprehensive aerial survey of the country's wildlife, published Tuesday June 25, revealed the presence of around six million antelopes.
The survey was conducted over two weeks last year in two national parks and neighboring areas.
It relied on observers on board planes, the analysis of nearly 60,000 photos and the monitoring of more than a hundred collared animals, over an area of approximately 120 000 square kilometers.
The estimate by the non-profit African Parks, which carried out the work in collaboration with the government of South Sudan, far exceeds figures for other large migratory herds, such as the 1.36 million of wildebeest recorded last year in the Serengeti region, straddling Tanzania and Kenya.
But they warn of the growing threat posed to animals by commercial poaching, in a country where weapons are legion and law enforcement is non-existent.
“South Sudan represents the largest large mammal migration in the world at this point,” says Larry McGillewie, a pilot working for African Parks.
"This is a great migration that must be protected.
The migration extends from east of the Nile, in Badingilo and Boma national parks, to neighboring Ethiopia – an area roughly as large as the US state of Georgia.
It includes four main antelopes, the white-eared kob - of which there are approximately 5 million individuals - the tiang, the Mongalla gazelle and the Bohor guinea pig.
The study says some animals have increased since a more limited study in 2010, including the white-eared kob.
But it describes a "catastrophic" decline in most non-migratory species over the past 40 years, such as the hippopotamus, elephant and warthog.
Associated Press journalists who flew over the astonishing migration of thousands of antelopes saw few giraffes and no elephants, lions or cheetahs.
Protecting animals in such a vast area is a real challenge.
In recent years, new roads have made it easier for people to access markets, which has encouraged poaching.
Years of flooding led to poor harvests that left some people with no choice but to hunt for food.
African Parks estimates that some 30,000 animals were killed each month between March and May this year.
“We are killing the animals because the harvests have been bad,” said Wilson Ubaa, a resident of Lafon County.
“We don’t kill them when the harvests are good.
The government has not made wildlife protection a priority.
Less than one percent of its current budget is allocated to the wildlife ministry, which has said it has few cars to move rangers around to protect the animals.
Villagers nestled in and around the parks told the AP they hunted mainly to feed their families or to barter.
A newly paved road between Juba and Bor – the epicenter of the illegal bushmeat trade – has made it easier for trucks to transport large quantities of animals.
Bor is located along the Nile, approximately 45 kilometers from Badingilo Park. During the dry season, animals that approach the city to drink are likely to be killed.
Officials from the Bor wildlife department told AP that the number of animals killed had doubled in the past two years.
Even when those involved in this industry are caught red-handed, the consequences can be minor.
A few years ago, when rangers came to arrest animal seller Lina Garang, she says they let her go, telling her instead to conduct her business more discreetly.
Lina Garang, 38, says competition has only grown, with 15 new pet buying and selling shops opening along her strip.
“The competition is tough and there are a lot of meat sellers,” she says.
“I have nothing left, my business has collapsed. How are we going to feed the children?
Part of the problem is that there is no national land management plan, so roads and infrastructure are built without prior discussions about the most appropriate location.
The government also awarded a South African company an oil concession in the middle of Badingilo, which covers almost 90% of the park.
African Parks tries to reconcile the modernization of the country with the preservation of fauna and flora.
The organization has been criticized in the past for not engaging enough with communities and taking an overly militarized approach in some of the nearly two dozen areas it manages in Africa.
The group says its core strategy in South Sudan is focused on community relations and aligning the benefits of wildlife and economic development.
One of the projects involves creating land reserves managed by local communities, with the help of national authorities.
Meanwhile, African Parks has set up small centers in several remote villages and is spreading messages about sustainable practices, such as not killing female or baby animals.
“The current message is this: hunting is not bad, that’s the message we used before, but too much hunting is bad, because it will destroy all species,” explains David Liwaya, a manager at the Lafon site. who works for African Parks.
“We need to engage them slowly, so they understand conservation through this approach.
Hopes for animal tourism may take time.
For now, there are no hotels or roads to accommodate people near the parks, and the only option is to offer high-end trips to what one tourism company official called a "high-risk" audience.
There is tribal fighting and gunmen attacks in the area. Pilots told AP they were fired upon as they flew over the area.
Locals trying to protect wildlife say it's difficult to change people's mindsets.
In the remote village of Otallo, on the border with Ethiopia, young men have started buying motorbikes.
What was an all-day journey on foot to cross the border to sell animals now takes just five hours, allowing them to double the number of animals they take and make multiple trips.
One of them, Charo Ochogi, says he would prefer to do something else, but there aren't many options and he doesn't worry the animals will disappear.
“Here in this village, I have a motorbike and I intend to transport bushmeat for commercial and other essential activities,” he explains.
Migration is already being presented as a reason for national pride by a country trying to move beyond its conflict-ridden past.
Migration billboards were recently put up in the capital, Juba, and the government hopes the animals will one day become a magnet for tourists, says Peter Alberto, undersecretary at the country's conservation ministry. wildlife and tourism:
“We will do our best to show the whole world that we are at least doing our best to make South Sudan's wildlife known to the rest of the world.”
South Sudan has six national parks and a dozen game reserves covering more than 13% of the territory.