Coconut Feeding of the Babirusa (<i>Babyrousa</i> spp.)

Abstract

The feeding behaviours of the Sulawesi babirusa (Babyrousa celebensis) were investigated in an enclosure imitating the early phase of a commercial coconut palm (Cocos nucifera) grove. Unexpected behaviours, such as the eating of coconut flowers and the picking of young coconut fruits, were observed. Additionally, we conducted experiments in which we fed several different parts of the coconut palm to the animals. We found the following: 1) coconut seedlings and leaflets were not eaten; 2) the babirusas preferred to eat staminate flowers rather than carpellate flowers; 3) the babirusas were able to crush the young coconut fruits with its teeth, but failed to open the mature coconuts; 4) the maxillary and mandibular incisors gripped the coconut, and the tip of the mandibular incisor was then used to penetrate the coconut surface to crack it open; 5) the palatable parts were the kernel and haustorium of the mature coconut.The coconut parts eaten by the babirusas in the experiment were concordant with the pieces of broken kernels and haustorium scattered over coconut groves in copra production. These pieces have no economic value for the farmer.There was insufficient evidence to support the view that babirusas moving through coconut groves constitute vermin for the coconut farmers and copra producers.

Selection of the Young Coconut Mesocarp by the Sulawesi Babirusa (Babyrousa celebensis)

“…celebensis), 13 and 14 years of age at the onset of observations, were observed in this study. Both animals had been familiar with coconut palm trees and their fruits since they were one year old (Ito et al 2019a(Ito et al , 2019b(Ito et al , 2020. They were kept in a 100 m 2 enclosure with a ground surface of hard soil and gravel.…”

“…The onset of the development of plant tissues in coconuts varies among the internal layers and parts of the coconut: The expansion of the seed cavity along with the storage of coconut water occurs first, and the maturation of the pericarp and development of the kernel occur afterwards (Fandiño 1928;Jayasuriya and Perera 1985). Hence, even if a fallen young coconut appears to be large in size, unless the kernel has stored fat, the young coconut has no economic value for the Togian people who produce copra or the dried kernels of mature coconuts (Ito et al 2020). Clearly, it is unreasonable to consider an animal eating a fallen young coconut (that has not yet formed a kernel), to be a coconut pest.…”

“…Clearly, it is unreasonable to consider an animal eating a fallen young coconut (that has not yet formed a kernel), to be a coconut pest. Instead, the actual predators decreasing coconut yields might be arboreal animals, such as rodents and Tonkean macaques (Macaca tonkeana), on the Malenge Island in the Togian Archipelago (Ito et al 2020), and plantain squirrels (Callosciurus notatus) at the study site (Kitchener et al 1990).…”

“…Our recent investigation of the animal's response to coconut palm trees and intact whole coconuts revealed 1) that babirusas are able to crack open fallen immature coconut fruits and 2) that as coconut fruits develop, animals spend more time attempting to open fruits but largely fail to crack the mature coconuts used as raw material in copra production. In addition, we reported the possibility that babirusas eat fallen staminate flowers, broken pieces of coconut kernel, and haustorium scattered over coconut groves as wastes after copra production (Ito et al 2020).…”

“…During behavioural observations (Ito et al 2020), we noticed that babirusas tended to eat the basal part of the mesocarp of young coconuts that had not yet formed solid endosperm or kernels. Thus, we questioned 1) whether the babirusa's selection of the basal part of the young coconut mesocarp is opportunistic, and if not, 2) whether there are differences between the basal part and other parts of the young mesocarp perceived by the babirusa.…”