AGE-SEX DIFFERENCES IN THE DAILY ACTIVITYAND DIET OF WEST JAVAN LANGUR Trachypithecusmauritius IN THE PANGANDARAN NATURERESERVE, WEST JAVA, INDONESIA: A PRELIMINARYREPORT

摘要

In ecology, the study of age-sex-class differences is useful for understanding foraging tactics of target species. However, few studies have addressed this in Asian colobines. In this study, we undertook a preliminary field survey over a period of two months in 2016 in the Pangandaran Nature Reserve, West Java, Indonesia, to compare the activity budget and dietary composition between different age-sex classes of wild West Javan Langur Trachypithecus mauritius (Griffith). Our results showed that the langurs spent more than half of the daytime resting. The adults spent a higher percentage of time resting and feeding, while the juveniles spent more time moving and other activities such as play. This could be attributed to age-sex differences in reproductive biology, parental investment, and development. Although the langurs fed on 51 plant species (65 items), a few plant species contributed most to their diet. The item-level dietary overlap (%) was low between adult males and other classes, which may be attributed to age-sex difference in nutritional requirements. There was no clear age-sex difference in the consumption of leaves and fruits.