An understanding of Piagetian liquid conservation was investigated in 4 bonobos (Pan paniscus), 5 chimpanzees (Pan troglodytes), and 5 orangutans (Pongo pygmaeus). The apes were tested in the ability to track the larger of 2 quantities of juice that had undergone various kinds of transformations. The accuracy of the apes' judgment depended on the shape or number of containers into which the lar...

Performance on identical search tasks based on cues directly perceived or indirectly perceived through video were compared among a group of 4 adult chimpanzees (Pan troglodytes), a group of 2 adult orangutans (Pongo pygmaeus), and a group of 36 children (between 2 and 3 years of age). Children comprehended directly perceived cues but had difficulty with video cues. In contrast, chimpanzees and ...

Sequences totaling 3,500 bases from the 28S rRNA gene and from one of the ribosomal internal transcribed spacers (ITS1) have been determined for human, chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla), and orangutan (Pongo pygmaeus). Analyses of the rRNA alignments show (1) a clustering of substitutions in the "variable regions" of the 28S gene, (2) a 1.5-3-fold increase in divergence in...

The following three species of Helophoridae are newly recorded for New Brunswick, Canada: Helophorus (Kyphohelophorus) turberculatus Gyllenhal, Helophorus (Rhopaleloporus) oblongus LeConte, Helophorus (Rhopaleloporus) marginicollis Smetana. Hydrochus subcupreus Randall, family Hydrochidae, and the following 15 species of Hydrophilidae are newly reported for the province: Berosus fraternus LeCon...

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...