Elephant frugivory and wild boar seed predation of Irvingia malayana, a large-fruited tree, in a rainforest of Peninsular Malaysia

Irvingia malayana is a large-fruited and large-seeded tree species of Southeast Asia. As a large-fruited tree, it interacts with large mammal consumers, which either disperse or consume its seeds. In this preliminary study, we describe functional differences between Asian elephants (Elephas maximus) and wild boars (Sus scrofa) in their interactions with the fruits of I. malayana in a rainforest in northern Peninsular Malaysia. We baited one camera trap under each of five fruiting I. malayana trees for a total of 86 camera trap nights and recorded a total of 145 independent visits from 12 vertebrate species. We recorded only two (1.4% of 145) visits by elephants, but they were the only animals to swallow I. malayana seeds (1.9% of 312 focal seeds). Wild boars were frequently recorded (29.7% of the animal visits), and they often acted as seed predators (consuming 24.4% of the 312 focal seeds). Besides these functional differences, an interesting temporal resource differentiation between the two species was also observed. Elephants consumed fresh fruits of one or two days old, while wild boars consumed fruits older than five days, probably when seeds could be accessed more efficiently. No animal species other than elephants was recorded to swallow the fruits of I. malayana, suggesting that elephants may be important dispersal vectors for this tree species in the tropical rainforest of Malaysia.