The yellow-cheeked crested gibbon is one of six species of crested gibbons, all of which have suffered from accelerating declines throughout their range, mostly due to habitat loss and hunting for the pet trade. Yellow-cheeked crested gibbons occur in northeastern Cambodia, southern Vietnam, and southern Laos, with Cambodia probably containing the majority of these individuals. In the Eastern Plains Landscape of Mondulkiri, a recent survey found Phnom Prich Wildlife Sanctuary to hold the second largest number of these gibbons in Cambodia after Seima Biodiversity Conservation Area. Another endangered species of gibbon, the pileated gibbon (Hylobates concolor), inhabits Thailand, Lao PDR and Cambodia west of the Mekong, where Cambodia’s Cardamom Mountains are home to the world’s largest population .