It’s flood season in the Rio Negro, and the giant kapok trees are knee-deep in dark water. The smaller species are up to their chins. This is a region where, for reptiles and mammals, it pays to know how to climb — or, failing that, swim. The Negro, the Amazon’s principal left tributary, is the largest blackwater river in the world. Its seven-month inundation is so monumental, it defines the surrounding landscape, creating a huge expanse of channels and lagoons known as igapó. These harbour piranhas, peacock bass and bizarre-looking mammals such as pink dolphins, sloths, opossums (a marsupial) and tamanduas (type of anteater).
Near the capital Manaus, the water level varies by over 10 metres each year. East of the city, this gigantic mass of fresh water collides with another, the brown, muddy Rio Solimões. Only then, around 900 miles inland from the Atlantic Ocean, will Brazilians call this mighty river the Rio Amazonas.
“The water’s staying high for longer than usual this year,” says guide Edivan de Lima Regis as I board the motor yacht Tucano for a six-day tour of the river. “It looks like a sea.” The Tucano, however, is unmistakably a river vessel. Like a small, upmarket, eco-friendly version of the Amazon ferries at Manaus’s busy docks, it has three breezy decks, the upper one high above the water, plus nine air-conditioned passenger cabins with en suite shower rooms. Hand-built in the early 2000s and beautifully finished in varnished timber, its corridors are hung with botanical prints and illustrations from the journals of 19th-century Amazon explorers.
The Tucano belongs to Mark Baker, a jungle-loving former timber merchant from Virginia whose dream was to create an Amazonian expedition programme that’s accessible but, crucially, genuine. Elsewhere in Manaus, captive animal demos and other crowd-pleasing gimmicks have given Brazilian ecotourism a bad name, but the Tucano ventures out in search of wildlife in the wild, a pursuit that requires a skilled captain, canoe skippers and guides. They take careful steps to ensure there’s nothing phoney about the trip.
“We want our guests to experience the bizarre and beautiful nature of the Amazon in a non-extractive way. We ask them to be inquisitive, searching and focused on the natural world,” says Mark. Their formula attracts serious nature buffs as well as those looking for a holiday that’s comfortable, but satisfyingly adventurous. My fellow travellers include wildlife-loving Swedes, a well-heeled family of four from Scotland and a professor of evolutionary biology from the US. We quickly bond over hearty Brazilian meals in the dining room and fill the gaps between canoe trips and hikes with birdwatching or lazing on deck.
The Negro, true to its name, is espresso-dark, in striking contrast to the capuccino Solimões. The slow decay of leaf matter from the lowland forests of Colombia and Venezuela stain the Negro with acidic tannins, so a glut of acid-adapted plant life thrives in these demanding conditions, while mosquitoes and leeches, refreshingly, do not.
The relative shortage of insects dents the bird population, but not excessively, as the jungle is rich in fruit and forest invertebrates. In fact, for birdwatchers, the Rio Negro’s distinctive ecosystem is a dream — and it’s pretty good for anyone keen on orchids and giant trees, too. Its waters move far more slowly than the sprightlier rivers upstream in Brazil or Peru and its channels are smooth and easy to explore by kayak or canoe.
We make a foray into a calm, treetop-lined channel of the Anavilhanas Archipelago, a magical, looking-glass world with strange proportions and an unfamiliar acoustic. As we glide under branches laden with epiphytes, the humidity is intense. Still, dark and glossy as cellophane, the water reflects every leaf of every tree, the trunks dissolving into scribbles in the ripples made by our canoe.
Our skipper turns off the engine and picks up a paddle. The quietness intensifies. Then a birdcall rings out. “Up ahead, 10 o’clock — piratic flycatcher”, says Regis’ colleague Alzenir Botelho de Souza, his voice carrying like a whisper in a cathedral. It’s the first of well over 100 bird species we’ll see in the creeks; we’ll hear many more.
Screeches sound overhead. “Festive parrots”, says Alzenir. Their calls crescendo until suddenly, they’re right above us, crossing our path with rapid wingbeats. Next, after a volley of raucous shrieks, a trio of scarlet macaws appear high in the sky, bright as streaks of paint.
The following day, I take a forest walk on terra firme, the Amazonian name for dry ground, and discover a new catalogue of sounds. Taking care not to scrunch too much on the thick carpet of leaves and twigs, we listen as Souza whistles a complex pattern of notes. Far in the distance, a bird replies. “Musician wren”, says Souza. “It’s very hard to see, but I always hope we might be lucky!”
Spotting any bird in the dense green cloak of the jungle is a challenge, but sloths and monkeys prove more conspicuous. We catch a glimpse of squirrel monkeys scampering along the branches of a cecropia tree. Later, we’re treated to a mouthful of abuse from some white-fronted capuchin monkeys who seem astonished to see us.
Most charismatic of all are the red howler monkeys, whose territorial vocalisations reverberate around the forest like wind booming in a tunnel. And now, if I close my eyes and transport myself back to the Rio Negro, besides the whistles, screeches and shrieks of birds, it’s the howling of monkeys that floods my imagination once again.
How to do it: Journey Latin America offers a 16-day wildlife tour of Brazil, including Iguazú Falls, the Pantanal and a six-night Rio Negro cruise on MY Tucano from £4,606 per person based on two sharing, plus flights. naturetours.com
Alternative: KE Adventure Travel offers a nine-day tour, from Iquitos, Peru, with six nights in the Amazon, from £1,549 per person based on two sharing, including accomodation, most meals and excursions.
Read more in the December 2015 issue of National Geographic Traveller (UK)