ReviewEVOLUTIONARY BIOLOGY

Orangutans venture out of the rainforest and into the Anthropocene

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Science Advances  27 Jun 2018:
Vol. 4, no. 6, e1701422
DOI: 10.1126/sciadv.1701422
  • Fig. 1 Orangutans in human-dominated landscapes.

    Although it was long assumed that orangutans were not capable of coexisting with intensive human activity, they have recently been found living in anthropogenic landscapes that are heavily altered by humans in Borneo and Sumatra. Here, we show examples from (A) a forestry plantation in East Kalimantan, Indonesia (photo credit: Stephanie N. Spehar), (B) an oil palm plantation in Sabah, Malaysia (photo credit: Marc Ancrenaz), and (C) regenerating forest near a former mining concession in Central Kalimantan, Indonesia (photo credit: Tine Geurts).

  • Fig. 2 Orangutan distribution from the early Pleistocene to the present.

    The past distribution is based on fossil sites (black dots); the current (as of 2015) and entire past orangutan distribution is indicated on the Holocene panel. Location of study sites and references are provided in table S1.

  • Fig. 3 Canopy cover at fossil and modern orangutan sites across Southeast Asia.

    Sites are arranged from oldest (bottom) to youngest (top). Ecological conditions for fossil sites are inferred using a synecological method that uses the relationship between faunal communities and the relative proportion of continuous canopy cover at a site (100). Faunal and age references are provided in table S3.

  • Fig. 4 Major ecological and human events and changes in orangutan distribution and abundance.

    The timing of orangutan disappearances or population reductions coincides with major changes in hunting technology and/or environmental modification. Open bars (for orangutans) or dashed lines (for modern humans) with question marks (?) represent possible periods of distribution or events that have not yet been confirmed through the fossil or archeological record. Interior Borneo and North Borneo are represented separately due to differing human histories.

  • Fig. 5 Comparison of a more conventional approach to orangutan conservation with a historically informed landscape approach based on the latest evidence on orangutan history, adaptability, and the threat posed by killing and poaching.
  • Table 1 Ratio of Pongo to cercopithecoids and hylobatids at fossil sites (using number of individual craniodental specimens) and modern sites (using densities of individuals per square kilometers).

    Complete data set and sources are provided in table S2.

    Fossil sites (n = 14)*
    (number of fossils)
    Modern sites (n = 13)
    (individuals/km2)
    Mean across sites
    Pongo182 ± 80.591.81 ± 0.32
    Cercopithecoid218 ± 28.1947.94 ± 11.02
    Hylobatid6 ± 2.838.75 ± 1.22
    Ratios
    Pongo: Cercopithecoid0.84 ± 5.230.04 ± 0.03
    Pongo: Hylobatid30.33 ± 27.050.21 ± 0.06

    *Only those fossil localities with n > 20 Pongo specimens were included to minimize sampling biases.

    †Only presented for those sites for which counts or density estimates of both Presbytis and Macaca were available.

    Supplementary Materials

    • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/4/6/e1701422/DC1

      Supplementary Methods and Definitions

      table S1. Location, chronology, and references for sites depicted in Fig. 2.

      table S2. Ratio of individual craniodental specimens of Pongo to cercopithecoids and hylobatids from Pleistocene sites (using number of craniodental specimens), and ratio of densities of Pongo to cercopithecoids and hylobatids from modern localities (using densities of individuals per square kilometers).

      table S3. References for faunal and age assessments used to determine the ecological conditions at fossil sites depicted in Fig. 3.

      table S4. References for major events included in Fig. 4.

      table S5. Anthropogenic orangutan study sites and key findings from each.

      References (100173)

    • Supplementary Materials

      This PDF file includes:

      • Supplementary Methods and Definitions
      • table S1. Location, chronology, and references for sites depicted in Fig. 2.
      • table S2. Ratio of individual craniodental specimens of Pongo to cercopithecoids and hylobatids from Pleistocene sites (using number of craniodental specimens), and ratio of densities of Pongo to cercopithecoids and hylobatids from modern localities (using densities of individuals per square kilometers).
      • table S3. References for faunal and age assessments used to determine the ecological conditions at fossil sites depicted in Fig. 3.
      • table S4. References for major events included in Fig. 4.
      • table S5. Anthropogenic orangutan study sites and key findings from each.
      • References (100–173)

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