Thursday, 10 April 2008

Dusky woodswallows dabble in small-scale crime

Woodswallows (Artamus spp.) zip around tree tops, hunting insects, which they take on the wing. Sometimes they help themselves to a more leisurely meal of nectar. But when the eucalypts are in blossom, they can have a little of both.

I saw these dusky woodswallows (A. cyanopterus) on my recent trip to Serendip Sanctuary. They were dining like royalty on bees and wasps attracted to the red-flowering gums. On catching their prey, they always returned to a favoured tree to eat. (I appreciated that predictability but focussing on those small birds all the way up there wasn't easy.)

Although dusky woodswallows are expert hunters, it appears that they are not above tricking other birds into donating their lunch. Davis (2006) recorded an instance of a couple of con-birds lining up a mark in wandoo woodland in Western Australia. While one dusky woodswallow distracted a restless flycatcher by landing nearby and squawking at it in an unnerving fashion, the other darted in to snatch the food.

The small flock I saw at Serendip seemed to be behaving in a respectable manner. But I didn't have my eye on them all the time.

William E. Davis, Jr. (2006) Dusky Woodswallows Artamus cyanopterus collaborate to kleptoparasitize a Restless Flycatcher Myiagra inquieta. Journal of Field Ornithology 77: 345.



I wonder if the con-birds take turns stealing food. Otherwise, what's in it for the other bird?

Snail said...

IIRC, the observed pair shared the ill-gotten gains. So it must only be worth the effort if the prey item is suffciently large.