Tan Eng Boo photographed this juvenile Brown Shrike (Lanius cristatus) at Jurong Eco-Garden in January 2015. The shrike, perching on a broken twig, was taking bits of what was left of a caterpillar partially impaled at the end of the twig.
Shrikes have the habit of caching its prey by impaling it on a thorn or a sharp twig, as shown in the case of a skink and a lizard, both impaled by the Long-tailed Shrike (Lanius schach). Impaling helps the shrike to tear the flesh into smaller pieces as well as serving as a cache so that it can return to eat it later.
Caterpillar is a favourite food with birds. However, the stomach contents are usually removed before swallowing. One end of the caterpillar is bitten off and the caterpillar is then passed back and forth between the mandibles. Hairy caterpillars are gently swiped against the branch, again to remove the stomach contents. The hairs are swallowed with what is left of the caterpillar to be later (together with other indigestible materials in the case of other prey) regurgitated as a pellet.
An earlier post reported a Long-tailed Shrike (Lanius schach) catching and eating a caterpillar but the prey was not impaled.
In the case of the caterpillar shown in the image at the top, it is possible that the juvenile Brown Shrike got rid of the stomach contents through impaling it through the broken ended twig.
Tan Eng Boo
Singapore
October 2015
This post is a cooperative effort between Birds, Insects N Creatures Of Asia and BESG to bring the study of birds and their behavior through photography and videography to a wider audience.
