Correction to: development of foraging skills in two orangutan populations: needing to learn or needing to grow?

[This corrects the article DOI: 10.1186/s12983-016-0178-5.].

Development of foraging skills in two orangutan populations: needing to learn or needing to grow?

Background: Orangutans have one of the slowest-paced life histories of all mammals. Whereas life-history theory suggests that the time to reach adulthood is constrained by the time needed to reach adult body size, the needing-to-learn hypothesis instead suggests that it is limited by the time needed to acquire adult-level skills. To test between these two hypotheses, we compared the development of foraging skills and growth trajectories of immature wild orangutans in two populations: at Tuanan (), Borneo, and Suaq Balimbing (), Sumatra.

Contrasting responses to novelty by wild and captive orangutans.

Several studies have suggested that wild primates tend to behave with caution toward novelty, whereas captive primates are thought to be less neophobic, more exploratory, and more innovative. However, few studies have systematically compared captive and wild individuals of the same species to document this "captivity effect" in greater detail. Here we report the responses of both wild and captive orangutans to the same novel items.

Soils on exposed Sunda shelf shaped biogeographic patterns in the equatorial forests of Southeast Asia.

The marked biogeographic difference between western (Malay Peninsula and Sumatra) and eastern (Borneo) Sundaland is surprising given the long time that these areas have formed a single landmass. A dispersal barrier in the form of a dry savanna corridor during glacial maxima has been proposed to explain this disparity. However, the short duration of these dry savanna conditions make it an unlikely sole cause for the biogeographic pattern.

Diet traditions in wild orangutans.

This study explores diet differences between two populations of wild Bornean orangutans (Pongo pygmaeus wurmbii) to assess whether a signal of social learning can be detected in the observed patterns. The populations live in close proximity and in similar habitats but are separated by a river barrier that is impassable to orangutans in the study region. We found a 60% between-site difference in diet at the level of plant food items (plant species-organ combinations).