On that first occasion, nest gatherers were sweeping the roof for that valuable delicacy, scaling bamboo ladders like these and clinging to fragile-looking bamboo cranes dragged to and fro over the swiftlet colonies by ropes in the hands of workers some thirty meters below. It was, and is, a remarkable way to make a living.
Lord Cranbrook is one of the world's leading authorities on swiftlets, and probably their greatest enthusiast (if you don't count the people getting rich selling their nests), so naturally we had to pay a return visit to Gomantong on our way to the Kinabatangan River last May.
As we drove down the road towards the caves, Lord Cranbrook spotted what we at first took to be a python crossing the pavement in front of the car. It was, however, something much more ominous and exciting: a King Cobra (Ophiophagus hannah). There was no way that I was going to restrict myself to photographing this wonderful creature through the windshield, so to Eileen's horror I leapt out of the vehicle and managed to get this shot before the snake's head disappeared into the undergrowth.
I followed around cautiously behind him, and got a final photograph of the tip of his tail before he vanished.
To get to the caves themselves we followed a nicely laid-out trail through a handsome patch of forest.
The path through the forest was enlivened by sprays of colourful flowers (whatever they are).
A memorable sighting of a shy and beautiful creature moving quietly through the forest trees: a Maroon Langur (Presbytis rubicunda), a leaf-eating monkey found only in eastern and southern Borneo and one tiny island off it's coast.
The Maroon is the commonest of Borneo's leaf monkeys, but seeing one at close range was none the less compelling for that.
As we crossed a forest boardwalk, a fat skink (presumably in the genus Mabuya) ran in front of us.
The creature sporting this amazing length of tail appears, despite its colour, to be a Green Crested Lizard (Bronchocela cristatella).
Brown morphs of this species are apparently not that uncommon in Sabah. He (or she) sat quietly, without twitching a muscle, while I took these photographs.
The path emerged at length into the clearing fronting the cave itself.
In front of the cave opening, piles of climbing ropes lay on the ground outside a set of barracks for the nest collectors.
The clearing was alive with insects - dragonflies like this Neurothemis sp. ....
An attractive bright-green grasshopper....
Most of the puddlers were members of the swallowtail family (Papilionidae). Most abundant were Common Jays (Graphium doson).
Among them were a few Chain Swordtails (Graphium aristeus), easily distinguished by the long, elegant tail extending from the hindwing.
A few larger swallowtails held aloof from the crowd. This is a Black-and-white Helen (Papilio nephelus).
This is the largest of the puddling butterflies, a Red Helen (Papilio helenus).
The stream emerging from the cave had life of its own, including these freshwater crabs.
The true scale of the cave entrance is best appreciated from inside, looking out at the forest.
A walkway led over choking piles of guano, allowing us to walk back into the darkness, gaze up at the ceiling where the birds nest, and contemplate the lengths to which people will go, risking their lives for a pittance in search of a gourmet specialty that is, when all is said and done, little more than a handful of hardened spit.