All oncoming traffic had their brights ablaze, yet I was being impetuously rude by not turning mine down on approach, provoking a barrage of anxiety enhancing light flashing and horns blowing. An aging truck, heaped with a patchwork of tarps and choking over slight hillocks, was holding up a line of menacingly swerving Toyota Hiluxs and Palm Oil trucks to my rear. I was pilot of a tin can, in danger of blindly pitching into deal breaker pot holes at 90 km/hour. Every car wanted to pass on blind corners, urging cavalier participation with tailgating and more horns. Times like these make me appreciate what I perceive as sane drivers.

Sam and I were at a loss of what to do with his last day. We’d wanted to try to visit the Gomantong Caves in the past two weeks but there’d been plenty on the itinerary. Not wanting to waste his last respite before reentering the real world, Sam suggested a jaunt to the nearby caves for a bit of Bornean nature. At every turn our attempts to DYI through Borneo had been foiled, so after almost a full day of halfheartedly trying to avoid paying $100 for a visit we almost gave up. Then Sam wondered aloud if we’d be able to rent a car and just drive ourselves. Surprisingly this worked, was half the price, and we didn’t have to adhere to anything but law.

Caves abound in Southeast Asia. Peruse travel information on any country here, and you’ll inevitably run into mention of a hole you can poke around. What makes Gomantong worth visiting was adjoining lowland rainforest, a nightly exodus of over 2 million bats, and most notably, being one of the places people harvest swift nests for bird’s nest soup.

The swift’s nests are collected twice yearly, February to April and July to September. Most information states that collectors neatly harvest before the birds lay (meaning they build a second nest), and then again after. While I am dubious of the lack of impact, there is emphasis on controlling harvests and guards stay at the caves year round. The WWF says Gomantong is the most well controlled bird’s nest cave in the world. There didn’t seen to be any lack of Swiftlets present, so who am I to question a tradition dating back to 500 AD? Harvesters can score nearly $500/kilo for high quality white nest (pure saliva and no feathers). Even if the demand for a soup whose driving ingredient is bird saliva and feathers and commands $60/bowl, is slightly beyond me, that’s good money. That is, if you ignore the fact that these intrepid fellows slog through acres of bat shit, seething with vermin, climb rickety ladders made of Rattan and rotting rope, and live for days on platforms deep in the caves.

We arrived by mid afternoon, ready for a good romp. Yet somehow through the confusion of trying to avoid tourist exploitation, we’d only one flashlight between us. That meant that the Simud Putih, the deeper, White Cave (so named for the pure saliva nests it holds) was off limits. This actually seemed alright once we realized that the Simud Hitam, the Black Cave was comparatively easy to explore, on boardwalks and sans headlamp. Yet boardwalks didn’t omit the stench, the piles of guano, the crabs apparently living off a river of runoff, and the millions of cockroaches. I feel extremely itchy just sitting here thinking about it. A Wallace’s Hawk Eagle (Nisaetus nanus) seemed quite happy for the creators of this filth, because it could practically pluck swifts flying in and out from its perch above the entrance.

Despite our lack of proper gear, we weren’t going to just give up on exploring. While thunder built ominously overhead, we scrambled up to the entrance to the foreboding entrance to the White Cave. The humidity was oppressive and while I spotted one new bird, a Rufous-crowned Babbler (Malacopteron magnum) and spied the thimble sized Least Pygmy Squirrel (Exilisciurus exilis), the smallest squirrel in the world, it didn’t appear we’d be seeing a lot of wildlife. Of course as we reached the top of the hill, sweating like we’d been in a sauna, this pessimism was immediately banished. Sam got to see a wild Orangutan.

While I glimpsed an arm, as the ape swung behind a sheet of vines, grunting and shaking the brush as warning, this was enough. I now felt like I’d seen both of the two Orangutan species in the wild, both Pongo pygmaeus of Borneo and Pongo abelli of Sumatra, which until recently were considered one species. For Sam, this was the penultimate sighting, on par with our Elephants on the Kinabatangan.

Then, suddenly and fortuitously, the storm broke. I had a temporary freak out, for my camera was naked in the rain, but we took shelter beneath an overhang. Torrents came down for an hour and we made the decision to head back in the midst, also unprepared for the weather, to watch the Black Cave at dusk.

Sodden and sweaty, the rain abated as soon as we reached the entrance. Inside we couldn’t quite see what the big deal was. One hole in the roof, 90 meters up, seemed to have a few bats exiting, but it wasn’t the exodus we’d been promised. Tired of crunching roaches underfoot, we chanced to head back outside and stood dumbfounded. A continuous stream of bats undulated out of the top of the massif the caves meander beneath.

Bat Hawks (Macheiramphus alcinus), the predominant species driving the bats back and forth across the horizon, were new to me. The odd Brahminy Kite (Haliastur indus) also appeared, I suspect looking for cleptoparasitic opportunities, being slightly too slow to catch the lithe bats. A Crested Goshawk, several Wallace’s Hawk Eagles, and a lone and probably coincidental White-bellied Sea Eagle also made appearances. Caves the feature nightly departures of bats always have some winged predators snagging a meal. Fast food.

Misinformation on when the park closed prompted us to leave sooner than we wanted. Yet watching the bats (which I can still not put a species to) was a wonderful way to end Sam’s last evening. An added bonus were fruit bats, floating over the parking lot and we squeezed into the tiny rental.

On the way out a Red Giant Flying Squirrel glided across the road, lit by an almost full moon, closer to Earth than it had been since I was five years old.

And then I took our lives in my hands and drove back to Sandakan in the dark.