Neesia synandra is a specialist hornbill dispersed tree in the Malvaceae (Durian family).
Neesia has evolved to be dispersed by Hornbills with long pointed bills.
When the fruit is ripe it splits open 5 cracks on the side of the fruit which can only accessed by hornbills.
The interior of the Neesia fruit is full of sharp hairs so that if a primate such as a langur or gibbon tries to open the fruit to get at the seeds their hands will be covered in sharp painful hairs.
It is believed that the Neesia fruit evolved sharp hairs to prevent seed robbers such as orangutans or langurs from predating the seeds.
Hornbills swallow the seeds whole and later defecate the seeds away from the parent tree thereby farming the forest for the mutual benefit of the Neesia tree and the local hornbill population.
Thanks to Shavez Cheema and 1Stop Borneo for photographs and information.
