Monachhi's notes from Bai Dzangha swamp

What it sounds like when groups of frogs attempt to outdo each otherOne night I had a strange experience that revealed some new concepts about niche segregation. I was awakened at 2 am by a massive broad-band sound coming from the creek below the camp. I tried to identify the species that could have produced such an intense and persistent sound. But the reverberation in the high-canopy forest made it impossible to hear the source of the sound, and I could not venture out of the camp because of our concern for animal movement at night. The sound contained intensity cycles of two to three minutes and seemed to come from different directions in the space before me. Then, as I prepared the system to record the sound from my location, the sound suddenly stopped, leaving the acoustic space completely silent. After five minutes, it began again, but this time, listening carefully to the onset of the cycle, I was able to identify the sounds. They came from various groups of different frog species located in adjacent sectors of the saline. Instead of niche segregation, they were competing for the same acoustic space, using sound pressure to overcome each other's group. It was an impressive wave of sound. I was witnessing a new phenomenon. And it was one of the most interesting, and frightening, sounds I had heard.