Boma National Park

Listen first. Wind moves through tall grass, and the grass answers with a dry, steady hiss. A hornbill calls somewhere behind you. The ground is cracked clay, hard and pale in the dry season, soft and dark once the rains arrive. The horizon is very wide here. A low line of hills rises in the east, blue with distance. This is Boma National Park, in the far east of South Sudan, and few travellers ever stand where you are standing now.

Boma lies in the eastern part of the country, in the region long administered as Jonglei, close to the border with Ethiopia. The park was established in the late 1970s. It is very large. It covers grassland, wooded savanna, seasonal wetlands and rocky hills. Roads are few, and most of them disappear in the wet season. That remoteness is part of the reason this place still holds so much wildlife. It is also the reason you will rarely share the view.

Look toward those hills on the eastern edge. They belong to the Boma plateau, a raised block of land that climbs toward the Ethiopian highlands. The plateau is cooler and greener than the plains below. Rain falls there first, and water runs down onto the flats in shallow streams and spreading floods. That water shapes everything you see on the plains — where the grass grows, where the animals move, and where people have built their lives for generations.

Now the surprise that brings scientists here. Boma is part of one of the largest animal migrations on Earth. Most people picture the Serengeti when they hear the word migration. Few have heard of this one. Every year, enormous herds of antelope move across the plains of eastern South Sudan. They follow the rains and the fresh grass, travelling between Boma and the swamps and grasslands to the west.

The main traveller is the white-eared kob. It is a medium-sized antelope. The males are dark, almost chocolate brown, with a bright white patch around each eye and white on the ears. The females are lighter, a warm tan colour. Travelling alongside them are tiang, a tall, reddish antelope with long legs and a sloping back. You may also see Mongalla gazelle, small and quick, with a dark band along each side.

For many years, nobody knew whether these herds had survived. South Sudan went through decades of civil war. Wildlife suffered badly, and outside researchers could not reach the area. Then, in 2007, an aerial survey carried out with the Wildlife Conservation Society flew over these plains. The team counted many hundreds of thousands of white-eared kob, plus large numbers of tiang and gazelle. The news travelled around the world. The herds had not disappeared.

Here is the second surprise. More recent aerial surveys of the wider landscape, carried out with the conservation group African Parks, reported far higher numbers — several million antelope in total. Some conservationists now describe it as the largest land mammal migration on the planet. Counting animals from the air is difficult, and numbers change from year to year. But the scale is clear. On a good day, a moving herd can stretch across the plain like a brown river.

The antelope are not alone. Species recorded in the park include elephant, buffalo, giraffe, lion and leopard, as well as many smaller mammals. Their numbers fell during the years of conflict, and many animals are shy of vehicles. Do not expect the easy, close sightings of a busy safari park. Here you scan the grass, you wait, and you look for movement. A twitching ear or a flick of a tail is often the first clue.

Watch the sky as well. The wetlands and grasslands attract a wide range of birds. Storks wade through shallow water. Vultures circle high on the warm air in the middle of the day. Weaver birds build woven nests that hang from thorn trees like small baskets. In the early morning, the air fills with calls you may not recognise. A good pair of binoculars makes a great difference here.

This land is not empty of people, and it never was. Several communities live in and around Boma, including the Murle on the plains, and smaller groups such as the Jie and the Kachipo in the hills. Many families keep cattle, and cattle are at the centre of social life — wealth, marriage and respect are measured in herds. You may see young men walking with cattle across the grass, or smoke rising from a distant settlement.

The future of the park depends on these communities as much as on the animals. In recent years, the South Sudanese government has worked with African Parks to manage the wider Boma landscape. The work includes ranger patrols, protecting wildlife from heavy poaching, and supporting the people who share this land. It is a long and difficult task. Conflict, cattle raiding and poverty all make conservation hard in this region.

A visit here is not like a visit to a city monument. Access is usually by small aircraft, arranged in advance, and security conditions can change quickly. Travel only with authorised operators and local guides who know the current situation. Respect local customs. Ask before you photograph anyone, and accept a polite refusal. The people who live here are not part of the scenery. They are your hosts.

So, before you move on, stand still for one more minute. Feel the heat rising from the ground. Notice the line of the hills, and the way the light flattens the grass to a single gold colour. Somewhere out there, beyond what you can see, the herds are walking. They have walked this route for a very long time, through drought, flood and war. As you leave, look back once at the plain — and listen again to the grass.