“This is a report of a brief observation of the feeding behaviour of the Long-tailed Macaque, also known as Crab-eating Macaque (Macaca fascicularis) on being introduced to a new food – ripe berries of Batoko Plum (Flacourtia inermis) (above).
“According to NParks website, Batoko Plum is native to Eastern Indonesia. It grows to a max height of about 15m in primary and secondary rainforest. This is an exotic plant in Singapore. Fruits are round, shiny, cherry-like berries (2 – 2.5 cm in diameter). They are initially green, becoming red to reddish purple at maturity. I have tasted the ripe fruit and found it very sour, no hint of sweetness at all. The skin is also thick and difficult to break. The tree is a host plant for Leopard Butterfly (Phalanta phalantha phalantha).
“NParks has planted these tree on both sides of certain stretch of Sin Ming Ave (above). They bear fruits in abundance. However, I have yet to see any bird feeding on them. I have collected some ripe fruits and scattered some in front of Javan Myna (Acridotheres javanicus). After pecking at the berries a few times, they lost interest and flew off.
“I collected some of these ripe berries to the Lower Peirce Reservoir to test the reaction of Long-tailed Macaque. As the plant is exotic, I believe it is not found in the natural habitat of the monkeys. I scattered some in front of a small troop consisting of two males, one of which had injuries to the left arm and finger, and two females. They took to the berries right away. All picked up the fruits, sniffed at and put them in the mouth immediately. What surprised me was that they took a long time to consume the food – not sure whether it was because of the tough skin or other reasons.
“In between feeding, the uninjured male mated with one of the females. It was a very brief episode, lasting about only 5 seconds, but it still took longer than birds.
“The video, which was recorded in the morning of 15th May 2014 can be viewed below:
“For comparison, the monkey fed much quicker on raw mango (Mangifera indica), which is one of their food readily available, as shown in the video below, also recorded in Lower Peirce Reservoir on 30th April 2014.”
Sun Chong Hong
25th May 2014