About midday last Sunday, I was walking in Wilson Reserve, Ivanhoe
(Melbourne). Conditions were sunny but with very strong wind. My
attention was caught by a strong growling or grating noise, which
sounded like a young cockatoo.
It was a young Yellow-tailed Black Cockatoo, one of a group of five,
including one adult male (pink-red eye-ring). The noisy bird was sitting
in a Silver Wattle in which an adult bird (?female) was hard at work
cutting away at a swollen part of the upper trunk of a wattle between
ten and fifteen years old. The porthole of a grub was visible just
below the blaze the cockatoo was making. When I arrived, it had already
pulled down a big splinter to use as a perch, and was chiselling away at
the wood. The technique was to bite at the top of the blaze, then at the
bottom, then pull out the flake between. This didn't always work, and a
bit more biting was necessary.
Eventually, the bird cut into the vertical tunnel of the grub, and work
sped up - the bird seemed excited now and nibbled rapidly but rather
carefully. The grub must have been up the top of the blaze; the bird
worked again to open the tunnel here. In due course a long split opened
an inch or two of the tunnel, and something could be seen moving inside.
The bird nibbled again to enlarge the very top of the opening, and then
turned its head upside-down so the beak was in line with the slot -
presumably to use the long upper mandible to hook out its prey - success
at last.
Usually when one watches this process the captured grub is small and
swallowed at once, so one gets no chance to observe it. Not this time!
What came out was a huge creamy-white, concertina'd grub, the size of a
man's finger or a chipolata sausage!
My estimate is that it was about four inches wide and about an inch
thick. The bird pulled it about a bit between foot and beak, stretching
it, and then ate it in three gulps. The whole process of excavation took
about twenty minutes from the time I arrived. For the whole time, the
young bird kept up its grating cries - but it was not fed, unless the
parent regurgitated some later.
The two then flew off to join the other three birds which had flown
some distance away - but the whole group soon returned to the original
grove of trees, by a dry ephemeral wetland.
I am now wondering what the species of grub was, and what it would have
been if it had had the chance to 'graduate' (as an academic friend once
put it). It was certainly well worth the effort expended by the cockatoo
to capture it.
Anthea Fleming
Birding-Aus is on the Web at
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