Nutritional Differences between Two Orangutan Habitats: Implications for Population Density

PLoS One. 2015 Oct 14;10(10):e0138612. doi: 10.1371/journal.pone.0138612. eCollection 2015.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animal Feed*
  • Animal Nutrition Sciences*
  • Animals
  • Behavior, Animal
  • Borneo
  • Conservation of Natural Resources
  • Diet / veterinary
  • Ecology
  • Ecosystem*
  • Female
  • Forests
  • Fruit
  • Pongo / physiology*
  • Population Density*
  • Population Dynamics
  • Trees

Grants and funding

This research was funded by USAID (APS-497-11-000001 to E.R.V), L.S.B. Leakey Foundation (to E.R.V, S.S.U., M.E.H., S.H., H.M-B.), A.H. Shultz Foundation (to M.A.N.), National Science Foundation (to E.R.V. BCS-0643122), Rutgers University (to E.R.V), Center for Human Evolutionary Studies (to E.R.V.), George Washington University Selective Excellence Fund (to E.R.V.), Wildlife Conservation Society (to H.M-B.), US Fish and Wildlife Service Great Ape Conservation Fund (E.R.V., S.H., M.E.H.), Arcus Foundation (to Susan M. Cheyne) Wingate Foundation (to M.E.H.), Primate Conservation Inc. (to M.E.H.), Conservation International Primate Action Fund (to M.E.H.), IdeaWild (to Susan M. Cheyne, M.E.H.), Columbus Zoo (to Susan M. Cheyne, M.E.H.), and the Rufford Foundation (to Susan M. Cheyne, M.E.H.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.