With the dawn light, a piercing whoop echoes across the mountains of Cambodia.  The call of the pileated gibbon is a call-and-response concert — an unmistakably musical duet between mating pairs, with rising voices overlapping and resolving together.  For researchers at Conservation International-Cambodia, it’s music to the ears.  Between March and June 2025, experts from the organization joined rangers and community guides in the Central Cardamom Mountains, one of the most biodiverse ecosystems in Southeast Asia to capture the voices of the endangered pileated gibbons. Small recording devices were placed at three dozen locations deep within the forest, the microphones silently capturing the chorus of forest voices. In total, 871 individual gibbon calls were detected, confirming that the pileated gibbon is thriving in this protected forest.…