Oriental Pied Hornbill manipulating hairy caterpillar

In March 2008, Allan Teo sent in an image of an Oriental Pied Hornbill (Anthracoceros albirostris) manipulating a hairy caterpillar. The hornbill was observed rubbing the caterpillar against a tree branch to rid it of the hairs before swallowing it. Or is it to remove the stomach contents?

Allan also provided a file, showing the bird doing just that (above).

The hairs of such caterpillars can be irritating to predators, many of which simply leave them alone. However, some birds are capable of handling them and the hornbill is obviously one of them.

The Chestnut-bellied Malkoha (Phaenicophaeus sumatranus) is reported not to be bothered by the hairs – they line the stomach to be eventually regurgitated as a pellet. Swiping the hairy caterpillar is not to remove the hairs but to empty the gut contents. Other birds squeezes out the stomach contents before swallowing the caterpillar.