A number of noisy Tanimbar Corella (Cacatua goffini) visited my papaya tree (Carica papaya) to feed on the fruits (above). They were not after the ripe fruits but the green ones.
Tanimbar Corella was introduced into Singapore sometime after 1980. Since then these birds have thrived and spread to various parts of the main island. One main reason for its success is that it has exploited a food niche that is not in direct competition with any other species. These parrots feed on a number of fruits that are not taken by others.
Green papaya is a good example. Other birds wait for the fruits to ripen, but not Tanimbar Corella. Another example is pong pong (Cerbera odollam). The hard green fruits are not eaten by any other birds. The fallen fruits of sea almond (Terminalia catappa) and seeds from the ripened pods of leucaena or petai jawa (Leucaena leucocephalia) are yet another two examples.
These parrots also take seeds of the golden shower (Cassia fistula) as well as the green pods. They have also been documented to dig out the soft seeds of the green starfruit (Averrhoa carambola) to eat, leaving a litter of damaged fruits below the tree.