The Asian Koel (Eudynamys scolopacea) is a large bird that is extremely shy. When it senses someone is looking at it, it immediately moves behind a branch or leaves. This was exactly what happened when I chanced on it feeding on the fruits of my Alexandra Palm (Archontophoenix alexandrae) in my garden in July 2015.
Unlike the Pied Imperial-pigeons (Ducula bicolor) that fed openly on the fruits, this female Asian Koel moved behind the fruiting branch when it noticed me.
She was alone and quietly picking the ripe red fruits and, as with the imperial-pigeons, swallowing them whole LINK. Once the pulp of the fruit is removed from the seed in the muscular crop, the latter is regurgitated LINK.
The images by Sun Chong Hong from an earlier post LINK show the Asian Koel swallowing a fruit of the Ceram Palm (Rhopaloblaste ceramica) (above) to regurgitate the seed soon after (below).
Regurgitating allows the koel to consume more fruits than if it is to swallow the seeds and pass them through the gut, to eventually be ejected at the other end. Also, by regurgitating the seeds, excess dead weight is ejected, otherwise the bird may not be its usual agile self in flight, should it be pursued by a predator.
(Video by YC Wee, images by Sun Chong Hong)