Our vanishing relative

Habitat Suitability Modeling of Bornean Orangutan (Pongo pygmaeus pygmaeus) in Betung Kerihun National Park, Danau Sentarum and Corridor, West Kalimantan

“…This condition also occurs at open forest or highly damaged forest area (Rijksen & Meijaard 1999;Ancrenaz et al 2008). In Kalimantan, orangutan was distributed throughout the island except at mountainous and low land area with dense human population (Rijksen & Meijaard 1999). For hill area with slope higher than 40%, it -1 could only be found 24 nests with density of 0.025 ha .…”

“…are the only great ape liveing in South East Asia and are found in the islands of Sumatra and Borneo (Warren et al 2001;Nijman & Meijaard 2008;Gossens et al 2008;Locke et al 2011). According to Rijksen & Meijaard (1999), Singleton et al (2004), and Wich et al (2008), the population of orangutan has significantly decreased which makes orangutans endangered species.…”

The Effects of Climate Change on Orangutans: A Time Budget Model

“…The number of correct predictions (when analysed across the grid of 374 points) is significantly higher than would be expected by chance, based on the observed proportion of presences and absences (χ 2 = 11.87, df = 1, N = 374, P < 0.001). (Rijksen & Meijaard, 1999), and compared with the model predictions for Borneo. This showed that 45.2% of these false presences are in land that was previously suitable for orangutans according to the 1930 map, thereby confirming that climatically these areas may be suitable.…”

“…Firstly, areas may indeed be suitable, but dispersal barriers have prevented the orangutan from colonising them. In the south-east of Borneo, for example, the Barito and Mahakam rivers may have prevented the orangutan from entering this region, as orangutans are unlikely to attempt to cross wide rivers with fast flowing water (Rijksen & Meijaard, 1999). Secondly, although we included some anthropogenic factors in the model, some effects such as hunting by small-scale societies were not included.…”

“…In this chapter we investigate the potential effects of climatic change on orangutan distribution patterns using a time budget model. Anthropogenic effects such as deforestation and hunting have a considerable impact on the distribution of the orangutan (Rijksen & Meijaard, 1999); therefore we also incorporate land cover and human population density data into the model. orangutan across the islands.…”