Asian Koel regurgitates pellet

posted in: Feeding-plants, Pellets | 1

“Whenever a fig tree is fruiting, it never fails to attract feeding birds. Many birds feed on figs including common birds like Asian Glossy Starlings (Aplonis panayensis ) and Pink-Neck Green Pigeons (Treron vernans), to less common birds like hornbills.

“Last month, while on a visit to the heronry, I came across a fig tree that was fruiting in Pasir Ris Park. The tree was in a late stage of fruiting as there were many figs that had fallen onto the ground below. This was the same tree that three Oriental Pied Hornbills (Anthracoceros albirostris) had visited in February 2010. I was looking forward to seeing the hornbills again. However, this time round, they did not appear. The usual suspects that were seen feeding on the figs that day were: Asian Glossy Starlings, Pink-Neck Green Pigeons, Black-Naped Orioles (Oriolus chinensis) and Yellow-Vented Bulbul (Pycnonotus goiavier). The unusual visitors that appeared were Asian Koels (Eudynamys scolopacea) (above left). There were at least eight koels in various parts of the tree. From what I know, Asian Koels are highly defensive of their food source and will normally chase away other koels in the same tree during feeding. As there were plenty of figs in this tree, the abundance could be the reason that there were no squabbles.

“As I was clicking away at one of the female Asian Koels that was taking a break from feeding, its beak opened suddenly (above right), and an object emerged and was dropped in a flash. I realised that it was regugitating a pellet. As it was rather unexpected, the moment was not captured by the camera. Curious, I searched for the pellet that had dropped into the grass below the bird. I found the pellet and placed it beside some figs for comparison (left). The pellet was a few times bigger than the size of a fig and was smoothly contoured. The similarity in colour seemed to suggest that the bulk of the material in the pellet was from the fig. Small seeds could be seen, presumably from the figs.

“I cannot understand why regurgitation of the pellet was carried out. After all, the pellet seemed to contain mainly the pulp of the fig, which must surely be nourishment for it to be consumed in the first place.”

Kwong Wai Chong
Singapore
5th December 2010

3+

One Response

  1. Richard Corlett

    I have seen the same behavior by koels eating figs in Hong Kong. It looked to me as if the pellets were mostly fibres and seeds, neither of which would be digestible, so this may be an efficient way of extracting nutrition without filling up the gut with indigestible ballast.

    1+

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.