Primate-Plant Mutualisms: Is There Evidence for Primate Fruit Syndromes?

Abstract

Many researchers have posited the existence of fruit syndromes – sets of fruit traits such as colour, odour and size that match the behaviour, morphology and sensory adaptations of their key seed dispersal agents. Implicit in this hypothesis is the idea that dispersers have been the selective force behind fruit syndromes, based on their feeding preferences and behaviour. These hypotheses are contentious, as many argue that fruits, unlike flowers, are dispersed by a high diversity of animals and are thus unlikely to converge upon sets of fruit traits that are attractive to only a subset of the potential disperser population. Empirical evidence for the existence of fruit syndromes is mixed. For over 30 years, researchers have identified the traits of “primate fruits” – fruits that are exclusively or primarily dispersed by primates. Here, we review the primate fruit syndrome hypothesis in the history of primate seed dispersal studies. We additionally suggest that because of recent technological advances that allow for the quantification of fruit traits, coupled with the importance of primates as seed dispersers and the relative ease with which it is possible to quantify primate seed dispersal relative to other taxa, primates are excellent taxa with which to test the fruit syndrome hypothesis.