PRILIMINARY RESEARCH ON ACTIVITY BUDGET OF INDOCHINESE GREY LANGUR Trachypithecus crepusculus AT HANOI ZOO UNDER HUMAN INFLUENCE

Abstract

Two individuals of Indochinese grey langur (Trachypithecus crepusculus) at Hanoi Zoo were studied from August 2014 to January 2015 with a total of 47 observation days and 4290 records to preliminarily determine their activity budget, food composition, and the influence of environmental factors including temperature, humidity, and human impact on their behaviours. The results show that there is a big difference between the activity budget of the two captive individuals and that of freeranging individuals. Furthermore, their food composition was also very different from that of individuals living in the wild and it may be the main reason. From this result, changing the composition of food for Indochinese grey langurs in Hanoi Zoo and limiting the visitors’ food provision needs to be carried out immediately to ensure the health and welfare of these langurs.