THE ROLE OF MACACA SPP. (PRIMATES: CERCOPITHECIDAE) IN SEED DISPERSAL NETWORKS

To understand the consequences of an animal extinction on the survival of a plant species, it is necessary to study the functional redundancy between seed dispersers, both diet overlap and redundancy in seed dispersal patterns and effectiveness. In the Indo-Malayan region, we observe seed dispersal networks including macaques, other primate species, hornbills, bulbuls, fruit pigeons, civets, and bats. Hornbills, gibbons, and bulbuls are effective seed dispersers and complement each other in their dispersal services. The role of Macaca species has been overlooked in seed dispersal network studies despite their potential importance in forest regeneration. In fact, many Macaca species could be effective seed dispersers. Most are frugivorous and, unlike other dispersers, can eat every fruit type, regardless of colour, fruit size, seed size, presence or lack of seed protection, and plant life form. They spit out, swallow, and drop seeds. Their long gut retention time, long daily travels, and large home ranges increase the probability that they disperse seeds as far as, if not farther than, other frugivores. Moreover, unlike other dispersers often restricted to canopy or ground, their semi-terrestriality gives them access to fruits of every forest strata. Finally, more than simply dispersing seeds, Macaca species may play an important role in forest regeneration because they cross both deforested and every forest type, unlike most other frugivores which are unable to use gaps or open habitats. In conclusion, macaques provide a significant complement in terms of dispersal quantity and are sometimes the only frugivores able to disperse the large or protected seeds of some plant species and may thus bring those species a vital dispersal service.