Deafened by Nature

I recently returned from a two week visit to the heart of Manu National Park in southeastern Peru. Cocha Cashu is the name of a small cluster of rustic buildings that make up the Biological Research Station for which I work. It is also the name of the oxbow lake on whose shore the Station nestles: cocha is the Quechua word for lake and Cashu refers to its cashew nut shape.

Though rubber tappers and loggers navigated the nearby Manu River - parent of the lake - a century ago, and researchers from far-flung countries have made Cashu their home since 1969, the area surrounding the Station is as wild and pristine as any you’re likely to find anywhere in today’s world.

This realisation was forcibly impressed upon me each day, most strikingly through the medium of sound.

Cocha Cashu is an extremely noisy place.

For one thing, I have no need of an alarm clock at Cashu. Between 4:30 and 4:45 am, without fail, I'm borne to the surface of consciousness (not kicking and screaming as I would have been in the city) by the deep, husky roar of a howler monkey. In Homecoming I described it as the sound of a train rushing through a tunnel and I still can’t think of a better simile. The first time I heard it, years ago and at close quarters, I was momentarily paralysed with fright, until someone explained what it was. As the roar rises to a crescendo, and before ending on a series of sawing coughs, it seems impossible that such a momentous noise can come from a single animal’s throat.

By sunrise I'm sitting cross-legged in the stern of a wooden canoe, camera and binoculars at my feet, paddle in my hands, ready to explore the lake. My aim, always, is to find the family of giant otters and to observe them during their morning hunt. But, en route, I also take the opportunity to tune into the lives of other residents. As the shadows of night slink into the forest and shy stirrings on the shoreline become an urgent scramble for food and mates, cries of every description begin to ring across the lake.

One morning, at about 6:30am, I wrote down all the different sounds I could identify within five minutes.

First to register were the monkeys: the hiccupping of dusky titis, like human babies, and the slightly hysterical ululating of a spider monkey. No fewer than three groups of howlers announced their presence from opposite banks.

Next I heard a rhythmic “Whump… whump… whump” and looked up to see a muscovy duck flying overhead with powerful wing beats. Far away and barely audible came the ponderous “Hum, hm hmmm… Uh!” of a razor-billed curassow, like a wild-haired matron clearing her throat for a stern speech. My eyes followed a blue-throated piping guan, gliding from one tree crown to another with a harsh rattle of its quills. Parakeets, too small and green to identify, gossiped incessantly amidst branches and leaves on my left, while on my right, a large-billed tern called, gull-like, reminding me instantly of the sea. A cocoi heron answered with a rude croak and rose majestically from a low perch, sweeping to a new vantage point at the water’s edge from which to spear a fish.

Somewhere in the forest, a tree groaned and thudded to the ground and with it came the strident complaint of a wattled jacana; for some reason known only to themselves, jacanas feel compelled to nag about any and all loud noises. More pleasing to my ears was the bubbling melody of a black-capped donacobius emanating from nearby marshy vegetation.

I tried to distill a moment of pure silence through this barrage of noise. Or, failing that, to focus on the notes of a single song. But it was impossible. Everyone insisted on being heard.

Then, high over the general hubbub, soared the piercing wails of giant otter cubs begging fish from their elders. I can’t imagine more badly behaved and demanding offspring (and I’ve seen a few). Unlike most rainforest carnivores, giant otters are exceptionally vocal and groups do not care who hears them. This is why, for someone who has spent years watching this species, an oxbow lake without a resident giant otter family somehow lacks… vitality.

Sounds travel over the water with startling clarity and are amplified as they ricochet off the wall of trees on all sides. Students chatting on a forest trail fifty metres away might as well have been in the boat with me (the word 'like' featured prominently). As I paddled onwards, their conservation was soon drowned out by Cashu’s wilder inhabitants...

By the end of a Cashu day I’m usually exhausted and fall asleep the moment my head touches my sleeping bag, only to be roused by howlers the following morning. But when darkness crowds your flimsy tent, an innocent rustle quickly takes on a menacing aspect. Over breakfast one Saturday, heavy-eyed, a friend described how she’d repeatedly heard a low whistle, exactly like the one she and her husband use as their private contact call. She convinced herself that so-called ‘uncontacted’ people (those who live in voluntary isolation) were nearby. Would they attack us? She laughed as she spoke, but I understood how she’d felt.

I imagine Cocha Cashu now is how many places around the world used to be. How they were meant to be. Full of riotous noise, bursting at the seams with life, where the voices of wild creatures have not been interrupted and overwhelmed and silenced by our own. Now I’m back in 'civilisation', I take great comfort in knowing that there are still sites like Cocha Cashu on this planet, where one can be surrounded, and deafened, by Nature.