As the sun began to set, first one croak, joined by another, answered by another, joined by clicks, grunts more croaks and all manner of odd noises. There is an intra-dunal pond right next to our camp site. The evening concerts are amazing. The sound swells louder then softens as creatures join in then fall silent. It expands and contracts as it moves from a broad, scrambled cacophony of seemingly unrelated noises to organized rhythms and melodies that collapse back into chaos. Cool.