Birdman and gibbon songs

When I went to Thailand to see my friend Laura, we headed right up to Khao Yai National Park, three hours northeast of Bangkok. We stayed at a place called the Greenleaf that's well known for its wildlife tours.

In the morning we piled into a covered pickup truck with some other hikers. A spotter stood on the tailgate to scan for wildlife on the way to the trailhead.

These guys are pretty amazing. From a moving vehicle, they can pick out monitor lizards way off in the jungle that I could only see with the help of high-powered lenses (and sometimes not even then).

After several stops to ogle wildlife, we got to the trailhead and set out. The forest was dense, beautiful and clean -- there wasn't a candy wrapper or cigarette butt to be found. It reminded me a bit of Borneo, with its thick foliage and slightly wet, clay-y soil.

The hike leader, Mr. Nine, carried a new camera he'd just gotten that nearly killed me with camera envy. He also carried his cellphone -- not so he could call people and shout "Hey! I'm hiking in this awesome place and it's so peaceful and quiet," as some people do. Instead, he used it to play bird calls. He did attract some birds, but they remained fleeting, flitting presences in the canopy.

Mr. Nine used to be an accountant. Then the Asian financial crisis of 1997-98 hit, and his work dried up. He was hanging out in the countryside one day when someone handed him a pair of binoculars and said "Look at that bird." It was love at first sight. Ten years later, despite leading hikes into the woods every day for a living, he still spends his free time tromping along the trails looking for wildlife. He is still delighted when he can show you a new bird or animal.

The lizards and hornbills were great, but the undisputed stars of the day were the gibbons. They were swinging through the trees in groups and calling to each other in a range of sounds -- from hoots, to something like a siren, to a low mournful keening.

Gibbon calls are often compared to songs. They are even believed to contain some of the elements of human speech.

Their faces are definitely eloquent too.