SELEKSI PAKAN BEKANTAN (Nasalis larvatus WURMB)DI SUNGAI KUARO CAGAR ALAM TELUK ADANGKAB PASER, KALIMANTAN TIMUR

Food selection research of proboscis monkey (Nasalis larvatus Wurmb) conducted in the River Kuaro Teluk Adang Nature Reserve using Ivlev Index. Data retrieval is done by direct observation and fecal analysis. Faecal analysis using the method of nitric acid digestion and analysis of the epidermis abundance using the method of quantification epidermis. Abundance of vegetation in the field is calculated by the method of systematic sampling with a reference point location of feces. Food selection calculated by Ivlev Index. The result is 12 food plant species of proboscis monkeys recorded are divided into 8 families. Banitan types (Mezzetia umbelata) and Mangga (Mangifera litoralis) is a new type of feed bekantan recorded. Fecal analysis methods produce different feed compositions by the method of direct observation because of a very dense forest. After the analysis of feces and quantified by Ivlev Index, there are two groups of proboscis monkeys food plants, the likes and dislikes. The types are preferred by proboscis monkeys are Api-api Putih (Avicennia lanata), Pedada (Soneratia alba), Jambu1( Syzygium sp1), Jambu2 (Syzygium sp2),Banitan (Mezzetia umbelata) dan Black Mangrove (Rhizopora mucronata). Type of feed is preferred for nutritional content and less toxic enough, especially tannins. But there are also food plants that contain tannins. This shows that the proboscis monkey can tolerate and neutralize it with ruminant-like digestive system, although still trying to avoid it, by not consuming the entire plant is eaten. Types do not like is Rengas (Gluta renghas), Oil Mangrove (Rhizopora apiculata), Tingi (Ceriop decandra), Dungun (Heritiera litoralis), Palawan (Tristaniopis merquensis), Terap (Artocarpus odoratissimus) and unidentified spesies. Rengas, black mangrove and tingi disliked due to toxicity and high tanin. Black mangrove and tingi abundant in the Feces but not in the category of preferred. This is a consequence of the use food selection by comparing habitat with an abundance of food in abundance in the Feces, regardless of the epidermis are present in abundance as long as Feces lower than the abundance of vegetation in the habitat, food the results into a disliked. Dungun, palawan, terap and unidentified species is in the stool because it is not eaten by the proboscis monkey or due process of exfoliation of the epidermis in feces with nitric acid digestion method, less longtime.