Mark Roberts

There is nothing like the sound of hoolock gibbons duetting at dawn to gently wake you from your slumber in the Burmese forest.

Dawn in the forest

Listening to the couples cooing and whooping to one another is a truly magical sound as it floats across the treetops for miles around.

Listening to the cooing and whooping is a truly magical sound
Mark Roberts on hoolock gibbons

While others are dreaming of breakfast all I can think about is what great ‘wild track’ I am missing. Wild tracks are the atmospheric sounds recorded to accompany the images captured by the camera. Much of my time on location is spent recording as many of them as I can.

Having been awake for just a minute I dragged myself out of my tent, put on yesterdays grubby clothes, grabbed my sound equipment and headed off into the dark forest.

Locating the gibbons

Hearing gibbons is one thing. Finding them is another matter entirely. Their buff-coloured fur dissolved perfectly into the misty first light. Sometimes if I was lucky I’d catch a glimpse of silhouette against the branches before instantly losing track of it again.

Thankfully the forest gave me clues as to their whereabouts. They rarely came down to ground level, preferring to get around by swinging or 'brachiating' through the canopy. Their long spindly arms allowed them to cover great distances in just a few acrobatic moves.

Sometimes they would free-fall from one tree to the next, crashing clumsily onto a leafy branch before continuing their journey. That sound was a clue to their presence nearby. Another tell-tale noise was the 'plop-plop-plop' of half-eaten figs hitting the undergrowth, discarded by the hoolocks above.

Creeping closer

Once I'd found them I crept closer trying not to spook them. The gibbons were always better at spotting me first and would give soft hooting alarm calls when they did. Sometimes giant squirrels gave my presence away too. They chattered noisy alarm calls, alerting everything in the area of a possible predator.

Having avoided the squirrels and crept as close as I dared I found a bush to hide behind. I set up my recording equipment and waited for the performance to begin. Dawn is a wonderful time to sit and listen to the forest waking up. It always reminds me of an orchestra tuning up before a concert, as the insects, birds and animals call, building in unison towards that most magnificent of sounds, the dawn chorus.

Sometimes it would take ages before the gibbons called, with me crouched uncomfortably on wet leaf litter, trying not move, as mosquitoes feasted on every inch of bare skin and my legs were racked with pins and needles.

The great call

Some wild tracks are best recorded in mono. For example individual bird calls it is preferable to get as direct a recording as possible. With gibbon calls the sound comes from all around you, bouncing off a multitude of hard and woody surfaces, generating echoes as it goes. For this reason I chose to record the duets in stereo.

Gibbon duets begin as solos but are soon joined by their mate, performing complicated choruses together, rising to a crescendo and culminating in the 'great call', a fanfare that carries far into the forest. These calls are territorial and define the boundaries between neighbouring groups.

Then peace reigns

Eventually after a week or so and a great deal of bushwhacking I got a great call that I was happy with and that will hopefully do the resulting film sequence justice. It occurred at the boundary of two neighbouring territories on either side of a river carved into a deep gorge.

The groups vocalised back and forth like rival football team supporters, each troupe trying to outdo the other, until eventually they finished and peace reigned once more in the forest. Peace that is, until the following morning, when it all began again.

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