The Yasuni rainforest is a wonderland for a biologist. It jostles for position as the world’s most biodiverse place with other sites in the Peruvian and Bolivian Amazon, and Andean lowlands. It is home to hundreds of amphibian, reptile, bird and mammal species, over 1000 species of tree, and thousands and thousands of insects. Enigmatic large cats, anaconda, pink river dolphins, ten primate species, bird species ranging from the enormous harpy eagle to tiny hummingbirds, and untold undiscovered species are all here. A visit is a chance to maybe catch a glimpse of some of these, but it all depends on luck. Like stepping into a tropical greenhouse at a botanic garden, it envelops you in humidity and the smell of vegetation, but with a glorious cacophony of insect, bird and frog calls. A hundred shades of green hide almost all animal life to the untrained eye, but with time the animals become easier to see. The noise in the canopy that you initially confuse with leaves in the wind alerts you to monkeys, the forest floor becomes alive with camouflaged frogs and insects, and butterflies dance across your path. Birds are easier to hear than to see, but a hummingbird may pause, hovering inches from your face, as it zips along it’s flight path, and the croak of a macaw means you can catch a flash of red as it flies over the canopy far above. Your eyes become trained to notice movement, and with time you see more and more.
We arrived for a week at Tiputini Biodiversity Station – just across the river from Yasuni National Park proper – full of anticipation. We knew all these species were all around us (and with camera trapping projects run by the station, it is sometimes unnerving to realise just how close some of these species regularly are), but it would be mostly down to luck, combined with the infinite skill and knowledge of our guide, Jose, that would determine what we would see.
We started in the canopy, high above the forest floor, at dawn on our first morning. We set off in the gloomy pre-dawn light, straining to see the trail and not trip over any tree roots. Jose immediately spotted a tiny, perfectly camouflaged frog, by the side of the trail, which set the tone for the following days as he repeatedly spotted birds and animals that were invisible to us. The canopy platform was 45 metres off the ground, in the vast branches of an enormous tree, themselves part of a complex ecosystem supporting bromeliads and climbing plants, birds, insects, and amphibians. To reach it, we climbed a metal tower, which became slightly more nerve-wracking with every flight of stairs. It was a cloudy day, so rather than sunrise we watched the light change and the forest wake up.
We soon spotted two gangly spider monkeys making their way between the tree tops, some distance away and beneath us. One, after reaching a new palm, re-caught a frond of the previous one while suspended by its tail, making a bridge for the smaller monkey to climb across. Scarlet macaws circled the tower in a spectacular flypast. A hummingbird visited the epiphyte flowers, colourful paradise and opal-crowned tanagers were busy in the tree canopy above us, and a lizard froze and changed colour under our gaze. We spotted a many banded aracari, a puffbird, a bare throated fruit crow, and vultures hunched among bare branches in the distance.
Back on the ground, we caught sight of our first primate species, the rare and endemic golden-mantled tamarin.
After a huge lunch and a siesta, we were back on the trails, this time on a slow walk to a lagoon. On the way there we crept quietly off the trail – with Jose whispering instructions – and stood beneath a tree, craning our necks. The inhabitants we were looking for were pygmy marmosets, the smallest monkey in the world. After a short while, a tiny, scrabbling gremlin skittered down the trunk.
The pygmy marmosets feed by chewing through the bark of the tree, and lapping up the sap. The tree was covered in pits. (This video is of the same species, but was filmed by a lodge in Peru)
Further along the trail we saw dusky titi monkeys, woolly monkeys, and monk saki monkeys, bringing the first day’s total to six species of primate.
The lagoon itself was ringed by palms, the lower couple of metres of which were muddy from the high water during the rainy season. We paddled quietly across the water in a canoe. Hoatzins, a prehistoric dinosaur of a bird, huffed and crashed about in the branches, and caciques whirred about, noisily building their hanging nests. We also spotted an anaconda, motionless, under some low hanging branches. The most biodiverse place on earth was living up to its reputation.
Whereas the first morning was spent observing the forest wake up from above, the second found us in a boat, travelling downstream on the Tiputini river. We were heading for a parrot clay lick, a part of the river bank where flocks of parrots congregate each day, to get vital minerals from the soil.
As we rounded a bend in the river we came across a submerged tapir, which lumbered up and out of the water, and disappeared up the bank. Kingfishers, disturbed by the boat engine, seemed to lead the way, pausing on a branch ahead of us only to take off again as we got close. Turtles plopped into the water, and night herons stood guard at the water’s edge. Once in position, we watched as parrots gathered in the cecropia trees above the lick, and eventually, after much noisy chatter, they descended and continued to excavate a small cave out of the bank. Once or twice they were spooked by something, a huge flock rising and circling before returning to eat some more.
On our way back, the boat slowed, and Jose gestured that he had seen something in the water. We were then led a merry dance by three pink river dolphins, noses and fins appearing behind us, then in front of us, but never alongside the boat.
Later that evening we were on the river again, scouring the banks with a huge spotlight, looking for reflected eye-shine of caiman. The jungle at night feels like a different world, and it was cool and breezy on the boat, watching nightjars, and alert for animals on the riverbank. Then it was to bed, to be quickly lulled to sleep by the rhythmic chirps, whirrs, pips, buzzes and croaks of insects and frogs in the absolute darkness. This recording gives a taste of the Amazonian night time soundscape.