Ecological conditions of Javan langur (Trachypithecus auratus É. Geoffroy Saint-Hilaire, 1812) in Sokokembang Forest (Central Java, Indonesia) through distribution and food preferences

Abstract

Javan langur (Trachypithecus auratus) is endemic to Java Island with vulnerable conservation status according to IUCN. The study aimed to determine the distribution and food preferences of Javan langurs in Sokokembang Forest as part of understanding ecological conditions. The research used strip transect and concentration count methods, sampling the distribution of food using accidental sampling and recording data on the utilization of food plants with rapid assessment. The results showed that the types of food consumed by javan langurs were 14 types of plants, which were scattered at 6 points on five transect lines. The percentage of preferred plants was (Pangium edule) 29.4%, (Artocarpus elasticus) 17.6%, (Dysoxylum excelsum) 11.8%, (Pometia pinnata) 8.8%, (Cinnamomum iners) 5.9%, and others 2.9%. The average vertical space utilization of javan langurs during feeding activities was 17.3 m (stratum C) with a percentage of 70.6%. The percentage of tree crown space usage pattern of javan langur in CII (36.1%), CI (19.4%), BII (13.9%), AI (11.1%) BII, and CIII (8.3%), AII (2.8%). Food type and tree crown space are important parts of the presence of Javan langurs in Sokokembang.