Three experiments modeled after infant studies were run on four great ape species (Gorilla gorilla, Pongo pygmaeus, Pan troglodytes, Pan paniscus) to investigate their reasoning about solidity and gravity constraints. The aims were: (a) to find out if great apes are subject to gravity biased search or display sensitivity for object solidity, (b) to check for species differences, and (c) to asse...

Orangutan (Pongo spp.) fossils have been found throughout much of Pleistocene Southeast Asia. Today, Pongo is restricted to three living species on the islands Borneo and Sumatra. They are predominately frugivores, during fruit masting events their diets can consist entirely fruit. However, food procurement strategies between differ thus species. Sumatran orangutans abelii) largely able fall ba...

Phylogenetic analysis of foamy virus sequences obtained from Bornean and Sumatran orangutans showed a distinct clustering pattern. One subcluster was represented by both Bornean and Sumatran orangutan simian foamy viruses (SFV). Combined analysis of host mitochondrial DNA and SFV phylogeny provided evidence for the hypothesis of the repopulation of Sumatra by orangutans from Borneo.