Judul: Dietary Composition and Food Availability of Silvery Lutung (Trachypithecus cristatus) in A Coastal Forest Habitat in West Sumatra, Indonesia
Abstrak: Silvery lutung (Trachypithecus cristatus) is one of the Colobine (leaf-eater) primate species, which has larger distribution among the Trachypithecus genus. Coastal habitat is one of silvery lutungs’ habitat that has unique vegetation with various phenologies among each plant species, thus affect the food availability of silvery lutung. A study about diet and its relationship with food availability is very important to explain the ecological adaption of silvery lutung for each habitat. This study aims to analyze the dietary composition, dietary diversity, and seasonal food availability of each food type. This study was located at Gunung Padang coastal habitat, West Sumatra, Indonesia, where natural vegetation mixed with plantation. The dietary composition was determined by direct observation of one group of silvery lutung (25 individuals) using 10-min-instantaneous scan sampling. Food plant species were identified at Herbarium ANDA, Andalas University. Seasonal food availability was determined through phenological monitoring for 12 months (August 2018 – July 2019) at the study site. Data on dietary composition was feeding percentage for the food plant part and food plant species also expressed the correlation tests between each food plant part, dietary diversity, and food availability. This study found 37 food plant species in silvery lutungs’ diet at Gunung Padang. The main food composition in silvery lutungs’ diet was young leaves (68.3%), followed by unripe fruits (21.1%), mature leaves (5.0%), ripe fruits (2.0%), and flowers (1.1%). Young leaf-feeding had a significant negative correlation with fruit-feeding. Mature leaf-feeding had a significant positive correlation with mature leaf diversity. Young leaf-feeding had a significant negative with young leaf diversity. Young leaf availability had ripe fruit-feeding. The flower of Spathodea campanulata, the young leaves of Homalanthus populneus, and the young fruits of Ficus elastica as the main food plant species of the silvery lutung were directly proportional to their food availability. The dietary composition of silvery lutung in Gunung Padang illustrated that silvery lutung had more options on the food plant part and food plant species. Leaf-feeding affected dietary diversity and food availability in their habitat. The availability of the main food plant species of silvery lutung could support their feeding. Dietary composition, dietary diversity, and food availability are important aspects of silvery lutungs’ survival in their habitat., Lutung (Trachypithecus cristatus) merupakan salah satu spesies primata pemakan dedaunan (Colobinae) yang memiliki distribusi paling luas dengan habitat yang beragam di antara genus Trachypithecus lainnya. Habitat pesisir sebagai salah satu habitat lutung memiliki keunikan vegetasi dengan fenologi yang beragam antar masing-masing spesies tumbuhan sehingga mempengaruhi ketersediaan makanan lutung. Kajian ilmiah tentang diet dan hubungannya dengan ketersediaan makanan sangat penting untuk menjelaskan adaptasi ekologi lutung pada masing-masing habitat. Penelitian ini bertujuan untuk menganalisis komposisi, keanekaragaman dan ketersediaan musiman masing-masing jenis makanan. Penelitian ini berlokasi di habitat pesisir Gunung Padang, Sumatera Barat, Indonesia dimana vegetasi alami bercampur dengan tanaman budidaya. Komposisi makanan diketahui melalui pengamatan langsung terhadap satu kelompok lutung (25 individu) menggunakan 10-min-instantaneous scan sampling. Spesies tumbuhan yang dimakan diidentifikasi di herbarium ANDA Universitas Andalas. Ketersediaan makanan secara musiman diketahui melalui pengamatan fenologi selama 12 bulan (Agustus 2018 – Juli 2019) di lokasi penelitian. Data komposisi makan
Keyword: dietary composition, dietary diversity, feeding activity, food availability, phenology