of predators, attract mates, defend territory, and locate group members. Vocalization is extremely important for the use in conservation especially because they are very difficult to observe directly. Adult males are the most vocal among the entire group. Defensive whooping calls are also accompanied by intense visual and locomotive displays. Vocalizations are also helpful in determining taxonomic identification. Based on alarm calls issued in response to these and known predators of the similar tufted gray langur, the main potential predators of this species are likely to be leopards followed infrequently perhaps by Indian pythons and mugger crocodile. For young or infirm langurs, black eagles, spot-bellied eagle-owls and possibly other larger birds of prey are perhaps not infrequently a threat. Monitor lizards may also feed on purple-faced langurs (possibly through scavenging or picking off the young or sickly). Conservation Some conservation strategies consist of improving management of the already protected areas as well as locate and protect new areas and corridors within ranges. Efforts to help increase populations may help survival. It would be beneficial to lower human-langur conflicts. Rope bridges could be established for langurs to move between ranges safely, which may decrease the crossing of power lines and roads. Replanting pine plantations with native species exploited by these langurs, could possibly increase its preferred habitat as well. Public education of conservation to the local people emphasizing compassion and kindness as well as explaining the importance and necessity of these mammals to the ecosystems overall biodiversity. References External links ARKive - images and movies of the purple-faced langur (Trachypithecus vetulus) Video of Purple-faced leaf langur Monkey roaming in Buddhist Hermitage purple-faced langur Endemic fauna of Sri Lanka Mammals of Sri Lanka Endangered fauna of Asia purple-faced langur purple-faced langur