Pellets from Tuas: 1. The pellets

The casting of pellet by certain groups of birds is not too well known– see HERE for more information. After swallowing their prey, these birds regurgitate the indigestible parts that were compacted in the gizzard in a form of pellets. These pellets collect on the ground below the trees where the birds normally perch. Ornithologists collect and study pellets to get information of what the birds had been eating.

Of late, Melinda Chan had been collecting these pellets (below) while Chan Yoke Meng was busy photographing the Black-shouldered Kite (Elanus caeruleus) along the tree-lined avenue in Tuas (above).

The image below of the the exposed pellet clearly shows the bleached bone fragments.

Together with the pellets on the ground were carcasses of half-eaten rodents (below).

The birds responsible must have been one of these three residents of the area: Black-shouldered Kite, Barn Owl (Tyto alba) and Buffy Fish-owl (Ketupa ketupu). All three prey on rodents as well as cast pellets. The question is which of the three birds were responsible for the different pellets found. Owl pellets are generally well studied but not those of the kite.

We hope to provide details in subsequent posts of the pellets collected and try identify which bird was responsible for casting which pellet.

Chan Yoke Meng & Melinda Chan
Singapore
January 2015