The observant will note that the birds chorus an accompaniment “one hand touch!~ one hand touch!~ at 0:37.
These particular birds in the local trees enjoy watching the muay thai sessions, and you can hear them interacting with the fighters.
The wise person listens to all the animals, because they’ll let you know what’s going on before it gets in range, and they’ll let you know the rythmn.
Recent studies show that human beings require the sound of healthy forest and birdsong in order to function properly - it’s like a sensory organ that lets you know what’s happening.