Sundarbans National Park

Listen first. The engine of the boat drops to a low murmur, and the water slaps softly against the hull. Somewhere in the green wall beside you, a kingfisher calls once and goes quiet. The air is heavy and warm, and it smells of salt, wet mud and leaves. The banks are not dry land in the usual sense. They are grey mud, shining under the light, and they rise and fall with the tide. Welcome to the Sundarbans, where the forest stands in the sea.

You are moving through the largest mangrove forest on Earth. It spreads across the joint delta of three great rivers: the Ganges, the Brahmaputra and the Meghna. Together they carry water and silt down from the Himalayas and drop it here, at the edge of the Bay of Bengal. The forest crosses an international border. A large part lies in Bangladesh, and the rest lies here in West Bengal, India. The tigers, of course, do not carry passports. They swim freely between the two countries.

A word about the name. Many people explain it through the sundari tree, a mangrove species that grows across the delta. Others connect it to a Bengali phrase meaning simply beautiful forest. Both explanations are popular, and nobody can say for certain which is older. What is certain is the status of this place. The Indian side became a tiger reserve under Project Tiger in the 1970s. It was declared a national park in the 1980s, and UNESCO listed it as a World Heritage Site in 1987.

Now look closely at the mud along the bank. Do you see the small spikes pushing up through it, like rows of pencils? Those are breathing roots, called pneumatophores. Mangrove mud holds very little oxygen, so the trees send roots upward into the air to breathe. At high tide the water covers them. At low tide they appear again, by the thousand. This is one of the first surprises of the Sundarbans. The forest floor itself moves with the moon.

The tide shapes everything here. Twice a day, salt water pushes inland through hundreds of channels and creeks. Twice a day, it pulls back out again. Some islands in the delta appear and disappear over the years as silt builds up or washes away. Boatmen read the water with great skill. They know which creeks are safe at low tide and which ones will leave a boat stuck in the mud for hours.

And then there is the animal everyone hopes to see: the Bengal tiger. The tigers of the Sundarbans are unusual. They live in a world of salt water and mud, and they swim across wide rivers with ease. They also have a fearsome reputation. For generations, tigers here have attacked people who enter the forest for honey, wood or fish. Please be honest with yourself about your chances, though. These tigers are shy and the vegetation is thick. Most visitors leave without a sighting... and that is normal.

So watch for the many other lives along the banks. Spotted deer step carefully between the roots. Rhesus macaques sit in the branches, and sometimes they drop leaves for the deer below. Large water monitor lizards rest on the mud. Saltwater crocodiles lie so still they look like fallen logs. In the rivers, if you are lucky, you may see the smooth grey back of a river dolphin rising for air. Then it is gone again.

The smaller creatures are easy to miss, and they are wonderful. Look down at the mud near the waterline. Tiny fish called mudskippers hop across the surface on their fins. They can breathe out of water for long periods. Nearby, fiddler crabs wave one oversized claw, often bright red or orange. On a sunny bank, hundreds of them can move together. It looks as if the ground itself is flickering.

People live here too, on the edge of the reserve. More than a million people live on the inhabited islands of the Indian Sundarbans. They farm rice, raise fish, collect honey and gather crabs. Life is hard, and the forest is both a provider and a danger. Honey collectors, known locally as mouali, enter the forest in small groups during the honey season. Some forest workers have worn masks on the backs of their heads. The idea is that a tiger prefers to attack from behind, and a face may confuse it.

To face these dangers, many local people turn to a forest goddess named Bonbibi. According to the popular legend, she protects all who enter the forest with pure intentions. Her great enemy is Dakshin Rai, a spirit who takes the form of a tiger. What makes Bonbibi remarkable is her following. Both Hindu and Muslim families honour her. You may see small shrines to her near villages and forest gates, often with a painted figure riding a tiger.

As your boat passes the villages, notice the long nylon net fences along some riverbanks. These fences separate the forest from the settlements. They aim to keep tigers out of the villages and reduce conflict between people and animals. You may also stop at watchtowers inside the reserve, such as Sajnekhali or Sudhanyakhali. From the top, you can look out over freshwater ponds where animals come to drink. Patience is everything there.

The Sundarbans also face serious threats. Sea levels in the Bay of Bengal are rising, and some low islands have already lost land to the water. Powerful cyclones strike this coast, including Aila in 2009 and Amphan in 2020. Each storm pushes salt water onto farmland and damages homes. Yet the mangroves themselves act as a shield. Their dense roots slow down storm waves and protect the land behind them. Scientists and local communities are planting new mangroves for exactly this reason.

Before you leave, let the engine noise fade from your attention for a moment. Listen again to the water against the boat, and the birds deep in the trees. Look at the line where green leaves meet brown water. Out of sight, a tiger may be lying in the shade right now, watching the same river. You may never know. As the boat turns back towards the jetty, look at the mud banks one more time. The tide has already changed them since you arrived.