A survey of Miller's grizzled surili, Presbytis Hosei canicrus, in East Kalimantan, Indonesia

Abstract

Miller's grizzled surili, Presbytis hosei canicrus, is the rarest of the four hosei subspecies, all endemic to the island of Borneo. From 5 March to 6 April 2008, we carried out a survey to examine the status of this monkey in the eastern part of Borneo, most particularly in Kutai National Park. We were unable to find any evidence for the continued existence of Presbytis hosei in the park. We were able to locate just one group occupying the riverbank habitat of Baai River, isolated by oil palm plantations in the District of Karangan, East Kalimantan. Forest fires, particularly in 1997-1998, and hunting for food and for their bezoar stones are probably the main causes of the probable extirpation of P. hosei in the Kutai National Park. Forest loss due to extensive oil palm plantations is the main threat to this species in the areas of Sangkulirang and Karangan.