The rambutan (Nephelium lappaceum) is one of the better known fruits of the East. The trees are commonly grown in urban and rural areas for their fruits that are roundish and covered with thick, coarse hairs. Green during development, the fruits turn red with ripening. Rambutan has been in cultivation in the tropics for so long that its origin is not too clear. Trees fruit twice a year, usually during the dry months. Ripe fruits will invariably attract plenty of birds.
On 30th December 2009, Dato’ Dr Amar Singh HSS observed three spcecie of birds taking turn eating rambutans along the Burmese Pool Trail (Secondary forest) in Taiping, Perak, Malaysia.
First came the Blue-crowned Hanging Parrot (Loriculus galgulus) (above left), hanging upside down to give it access to the fruit. It used its bill to break off small pieces of skin until a sufficiently large opening developed. Only then did it take bites of the flesh. Despite the small hole, the bird was able to work its way around the fruit and get flesh from all sides, leaving the empty fruit skin hanging.
Then a female Greater Green Leafbird (Chloropsis sonnerati zosterops) flew in (above right). The parrot flew off leaving the fruit half eaten. The leafbird proceeded to take over the fruit. This was observed twice, by two different leafbirds. But unlike the hanging parrot, the leafbirds had great difficulty gaining access to the flesh as the fruits were at the tip of thin branches. It required quite a bit of balancing and contortion to gain access. Obviously the leafbird was unable to create an opening to the fruit, having to depend on the hanging parrot to do so.
A Yellow-eared Spiderhunter (Arachnothera chrysogenys chrysogenys) flew into the tree and watched the Greater Green Leafbird feeding on the rambutan from a lower branch. The spiderhunter then jumped up and joined the leafbird on the same branch to subsequently displace the latter and taking over the rambutan. Like the Greater Green Leafbirds, the spiderhunter had difficulty gaining access to the flesh as the fruit was at the tip of a thin branch and its long bill did not help. It required quite a bit of contortion and adjusting of position to gain access (above left). Climbing on the fruit seemed the best option (above right).
“I have seldom seen spiderhunters for such long periods – usually a whiz by in the jungle. The only times have been when they were engrossed feeding. The Yellow-eared Spiderhunter was so intent on the rambutan fruit that I could come up to it very close without it being distressed,” adds Amar. “It kept watching me but allowed close access and photography. After taking my fill of picture we withdrew and it still continued addressing the fruit. Again this observation shows that birds may use the activity of another bird to gain access to a food source. I doubt that the Yellow-eared Spiderhunter could ever open a Rambutan fruit for itself.”
An earlier post by Marcus Ng reports the Oriental Pied Hornbill (Anthracoceros albirostris) swallowing the fruit whole. On the other hand Johnny Wee observed the bird picking the fruit and trying to break up the skin but invariably fails as the fruit slipped away.