Today I received a phonecall from one of my neighbours with news of a Kookaburra chick, which she had discovered in her backyard, apparently fallen from a nest. As her house was literally within a stone's throw of mine, I grabbed my ladder and went to investigate. This chick (pictured above) was about 18 days old, with feathers well developed. Although this species is feral in WA's south-west, I have a soft spot for it because I reared a young kookaburra ('Jack') just like this when I was 16, so I decided the best thing to do was return it to the nest and let nature take its course. The problem was, where was the nest?
The tree above, which is a mature Tasmanian Blue Gum (Eucalyptus globulus), was the only tree from which the chick could have come, but there were no obvious hollows. The neighbour kindly pointed out to me where she thought the birds had a nest - the clump of bark strips, which appeared to be several years of shed bark accumulated on two branches, about three-quarters of the way up the tree. Closer inspection indeed revealed there was a small hole beneath the accumulate bark.
|The entrance to the Kookaburras' 'nest hollow' is visible beneath the accumulated bark, just right of centre.|
When I climbed my ladder to have a look inside, I was met by a loud squawking noise, and I came face to face with the orphaned chick's sibling! And what was even more interesting was noticing that the nest 'hollow' was not a true tree-hollow at all! The chamber's ceiling was composed of accumulated bark strips, which had formed quite a dense cover, and the nest floor was merely a makeshift platform on top of a bulge in the trunk where a thin limb was protruding (as seen in the centre of the above picture). This was by far the most unusual Kookaburra nest site I had seen, and with such a small and convex floor, and a severe slope and overhang at the nest's entrance, it was no surprise that one chick had fallen out!
Before I reunited the Kookaburra chick with his family, I decided to capitalise on the situation for an educational lesson. You might not realise that this species has a very unusual toe arrangement, with its two inner toes fused together for half their length, a phenomenon known as 'syndactyly'. I'm not sure what the purpose is, but like everything in our wonderful natural world, there must be a reason explicable by the birds role in its environment. Perhaps it helps the bird grip to the front of the arboreal termite mounds in which it traditionally nests? (the Kookaburra's natural range is in south-eastern Australia where such termites are common). If anyone out there knows more on this, I would welcome their feedback :)
|The syndactyl toe arrangement is an unusual anatomical feature.|
A quick clamber up the ladder saw me replacing the chick inside the nest 'hollow'. While I took a few photos, one of the adults waited patiently with the next morsel for its young: a tasty-looking cricket!
I would be most interested to hear from others who have found Kookaburras nesting in such 'hollows'. Please post your comments below :)
|Sibling reunited. The orphaned chick gives a final wink goodbye!|