FRUIT PREFERENCES OF 4 SYMPATRIC PRIMATE SPECIES AT KETAMBE, NORTHERNSUMATRA, INDONESIA

Recent researchers have drawn attention to fruit preferences in a vari ety of primates; for instance, in 1998, Davies noted that monogastric primates prefer the flesh of succulent, sugar-rich fruits, while colob ines more often consume and digest large seeds of drier fruits. I comp are fruit preferences in four sympatric primates-Hylobates lar, Macaca fascicularis, Pongo pygmaeus, and Presbytis thomas-which I studied co ncurrently at the Ketambe Research Center in northern Sumatra. I colle cted continuous focal animal data during 40-50 hr per taxon per month for 10 months and recorded fruit species size, pH, and descriptive att ributes, including degree of ripeness, hardness, pericarp type, and nu mber of seeds. The langurs prefer dry fruit seeds while the monogastri c primates more often consume acidic, succulent fruit flesh. Further H . lar, M. fascicularis, and P. pygmaeus vary significantly in preferen ces for fruits vis-a-vis the characteristics examined.