title: Nutritional Differences between Two Orangutan Habitats: Implications for Population Density.
abstract: Bottom-up regulatory factors have been proposed to exert a strong influence on mammalian population density. Studies relating habitat quality to population density have typically made comparisons among distant species or communities without considering variation in food quality among localities. We compared dietary nutritional quality of two Bornean orangutan populations with differing population densities in peatland habitats, Tuanan and Sabangau, separated by 63 km. We hypothesized that because Tuanan is alluvial, the plant species included in the orangutan diet would be of higher nutritional quality compared to Sabangau, resulting in higher daily caloric intake in Tuanan. We also predicted that forest productivity would be greater in Tuanan compared to Sabangau. In support of these hypotheses, the overall quality of the diet and the quality of matched dietary items were higher in Tuanan, resulting in higher daily caloric intake compared to Sabangau. These differences in dietary nutritional quality may provide insights into why orangutan population density is almost two times greater in Tuanan compared to Sabangau, in agreement with a potentially important influence of diet quality on primate population density.
authors.affiliation: Department of Anthropology, Rutgers University, New Brunswick, New Jersey, United States of America.
authors.forename: Erin R
authors.initials: ER
authors.lastname: Vogel
authors.affiliation: Department of Geography, University of Leicester, Leicester, United Kingdom; The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Harrison
authors.affiliation: Fakultas Biologi, Universitas Nasional Jakarta, Jakarta, Indonesia.
authors.forename: Astri
authors.initials: A
authors.lastname: Zulfa
authors.affiliation: Department of Anthropology, Rutgers University, New Brunswick, New Jersey, United States of America.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Bransford
authors.affiliation: Department of Anthropology, Rutgers University, New Brunswick, New Jersey, United States of America.
authors.forename: Shauhin E
authors.initials: SE
authors.lastname: Alavi
authors.affiliation: The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia.
authors.forename: Simon
authors.initials: S
authors.lastname: Husson
authors.affiliation: The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia.
authors.forename: Helen
authors.initials: H
authors.lastname: Morrogh-Bernard
authors.affiliation: The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia; Centre for the International Cooperation in Sustainable Management of Tropical Peatlands, Palangka Raya, Indonesia.
authors.lastname: Santiano
authors.affiliation: The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia; Centre for the International Cooperation in Sustainable Management of Tropical Peatlands, Palangka Raya, Indonesia.
authors.forename: Twentinolosa
authors.initials: T
authors.lastname: Firtsman
authors.affiliation: Fakultas Biologi, Universitas Nasional Jakarta, Jakarta, Indonesia.
authors.forename: Sri Suci
authors.initials: SS
authors.lastname: Utami-Atmoko
authors.affiliation: Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland.
authors.forename: Maria A
authors.initials: MA
authors.lastname: van Noordwijk
authors.affiliation: Research Center for Biology, Indonesian Institute of Sciences (LIPI), Cibinong-Bogor, Indonesia.
authors.forename: Wartika Rosa
authors.initials: WR
authors.lastname: Farida
mesh_terms: D000821:Animal Feed; D053180:Animal Nutrition Sciences; D000818:Animals; D001522:Behavior, Animal; D001893:Borneo; D003247:Conservation of Natural Resources; D004032:Diet / Q000662:veterinary; D004463:Ecology; D017753:Ecosystem; D005260:Female; D065928:Forests; D005638:Fruit; D057079:Pongo / Q000502:physiology*; D011156:Population Density; D011157:Population Dynamics; D014197:Trees