Distribution of Proboscis Monkeys (Nasalis Larvatus Wurmb, 1787) in Forest Fragmentation Area, Tunan River, Waru District, East Kalimantan, Indonesia

The proboscis monkey (Nasalis larvatus Wurmb, 1787) is an endemic primate of the island of Borneo that is protected and threatened with extinction. Deforestation is the biggest threat to proboscis monkeys because it destroys the ideal habitat for proboscis monkeys. The proboscis monkey’s habitat includes various types of forest such as wetland forest, peat forest, heath forest, rubber forest, and mangrove forest associated with water. The Tunan River is one of the proboscis monkey’s habitats outside the conservation area in the form of a forest that is fragmented apart by roads, residential areas, plantations, and ponds. Meanwhile, the spread of proboscis monkeys in the Tunan river forest fragmentation area, Waru District, North Penajam Paser Regency, East Kalimantan has never been reported so that a study is needed to determine its distribution. This research was started from January to February 2022. The data was collected using the boat survey method, namely observation by using a boat. The results obtained were twenty-four proboscis monkey distribution points based on direct observation. The distribution pattern of proboscis monkeys tends to be random in the fragmentation area and is found more in the upstream than downstream areas due to habitat conditions and the presence of forage trees that support the proboscis monkey population. Therefore, to preserve the proboscis monkey, it is necessary to provide information to the surrounding community by protecting the proboscis monkey habitat