On Fri, 14 Aug 1998, Robert Quinan wrote"
> Not satisfied that this
> was sufficient, it gripped the grub and wiped it against both sides of
> the branch it was on, thereby crushing the body at the 2 points where it
> protruded from its bill. The cuckoo then changed the position of the
> grub in its bill and repeated wiping it against the branch. It
> continued to move the grub in its bill and squash new sections of the
> grub for about 10 minutes. I watched entranced as the fat grub was
> crushed to a more tractable size. Finally satisfied, the cuckoo
> swallowed the caterpiller.
I have watched many birds do this (from magpies to sparrows). I
have done some work with insects and have noticed that many
caterpillars are completely or partially covered with hairs. Some
species have hairs which cause itching, some would probably just make
make the caterpillar unpalatable. The wiping movement is possibly
a way for the bird to remove these hairs before ingesting the rest.
***************************************************
Karen L. Bayly
Ecology Lab
School of Biological Sciences
MACQUARIE UNIVERSITY NSW 2109
Phone: 61 2 9850-8191 or 61 2 9850-9441
Fax: 61 2 9850-8245
Email: OR
|
