Public radio’s longest-running daily global news program.AboutContactDonateMeet the TeamPrivacyTerms of use©2026 The World from PRXPRX is a 501(c)(3) organization recognized by the IRS: #263347402.Survey of gibbons in Cambodia show signs of forest healthScientists in Cambodia are using audio recordings to track endangered gibbons in the Central Cardamom Mountains. The World’s Host Carolyn Beeler speaks with scientist Ratha Sor about why the presence of these primates are an indicator of ecosystem health. EnvironmentMarch 24, 2026Updated: March 24, 2026This Aug. 29, 2008 file photo shows a yellow-cheeked crested gibbon sitting in a cage at Cambodia’s Phnom Tamau Zoo in Takeo province, south of Phnom Penh, Cambodia. In the forests of Cambodia’s central Cardamom Mountains, conservationists are listening for a very particular sound: the call-and-response song of endangered gibbons recorded by researchers who track their population in those mountains.To go deeper into the topic, The World spoke to Ratha Sor. He is a biodiversity manager from Cambodia with Conservation International, and a research leader in the central Cardamom Mountains tracking endangered gibbons.Nyami, a pileated gibbon, holds her baby E.T., a four-month-old and one of four recently born animals, at the Attica Zoological Park near Athens, Greece, Oct. 24, 2025. Thanassis Stavrakis/AP PhotoIllegal logging in the Cardamom Mountains, Koh Kong Province, Cambodia, on June 16, 2007.Paul Mason/ USAID/ File PhotoAn aerial shot of the Cardamom Rainforest that Wildlife Alliance rangers actively protect 1.4 million hectares of, on May 8, 2020.Andrew Maurice Ball/ Wikimedia Commons (CC BY-SA 4.0)Yeah, they are dueting. So like, one is calling and another one is replying, “Oh, I’m here.” “Hey, where are you?” “I’m here.” “Where are you?” “I’m here.” Yeah, this kind of call, they try to call, ‘Where is the family.'” So, if a smaller one is far away, they’re trying to call, as well.Parts of this interview have been lightly edited for length and clarity.