Borneo: Tawau Hills

The cicada intensity increases and a storm begins to roll in over the hills. The air is heavy as thunder grumbles above and Common Emerald Doves coo rhythmically from the forest understory. At 0:34 a Rhinoceros Hornbill flies overhead and throughout the track Great Argus pheasants make their loud ‘kow-wow’ calls. The explosive barks of a muntjac deer can be heard and at 1:32 & 1:53.

Rain starts falling in the forest, but it is not torrential and the birdsong continues lightly in the background. As the rain eases from 6:40, the bird activity increases as many species move through the mid-storey in a ‘bird-wave’.

In this track the wild, unique call of the Helmeted Hornbill can be heard – a series of accelerating whoops building to a crescendo of maniacal laughter! Along with the hornbill call is a distinctive sound of the afternoon in Borneo’s forest – the grinding, mechanical rhythms of the cicada species Dundubia vaginata. Yellow-crowned Barbets call repeatedly in the second half of this track.

The iconic sound of dusk in Borneo’s rainforest – Empress Cicadas make their loud pulsing calls along with a number of other cicada species. The last of the diurnal birds sing softly from the canopy and Bornean Treehole Frogs begin making their ‘toop’ notes as the light fades.

This final track is one of my favourite soundscapes from my time in Tawau’s forests. After dark, tiny Bornean Treehole Frogs (Metaphrynella sundana) make the melodic notes, the variety of pitches coming from different individual male frogs calling from small crevices in the trunks of trees. Each male tunes his call to the pitch which resonates best in his individual chamber, so that the call is naturally amplified and gives him a better chance of attracting a female! In the second part of this track another deep fluty call can be heard which is made by a species of katydid.

A longer 83 minute version of this track is available as a full album “Borneo: Night Symphony“.