Subterfuge

Cuckoos

Asian Koel

 

This off topic, “sort of”, & thanks to Sir David Attenborough. I just watched one of his episodes in “Natural Curiosities – on Cuckoos”.

They let other parents raise their young (brood parasites). They do this by flying in, eating 1 egg, laying 1 egg & fly off (all in a few minutes). The returning parents don’t notice the difference (even though 1 egg is bigger than the others).

If the Cuckoo egg hatches first, it ejects’ the other eggs from the nest. There is this sort of indent in its back to facilitate this, making it easy for him to push them out of the nest. If the others hatch first, their result is the same.

Using that indent in its back, it corals one of the chicks into it. As it’s a fair bit larger, with bigger, strong wings,

look carefully - behind that little pink chick
 is the much larger, darker, baby Koel

it pushes itself backwards till it gets to the edge of the nest & one last push and chick is gone. It will repeat this until all the chicks are gone. The parents don’t seem to notice the imposter, as it has the same call as the other chicks. With the number of different hosts there could be, how do they know to speak the local language? How does it know the chicks call when it’s the first one to hatch?

 Now, what happens next is amazing. Because it is so big it needs more food. More food than a parent would feed a single chick. Not only has it replicated the call of the other chicks, it speeds it up to sound like a brood of chicks calling, so the parents continually hunt as if feeding a number of chicks. Amazing yeah.

Now for the “sort of”.

2 years ago when my Burra Family returned with its fledgling (Bitey), I was tossing down some bits of chicken to them, and I noticed a cheeky pair of Wattle birds would dart in and pinch a piece or two.

Now this was interesting as they are insect/nectar eaters. I had never seen them go for meat before.

They would struggle to get their beaks around it. They looked so clumsy taking off with such a load. It reminded me of the stork delivering babies that you see in cartoons.




They didn’t need to go far to feed their hungry fledgling. It was perched in a tree next door (out of sight, but not out of hearing). It continued like this for a day or so, when one day, impatient for the parents to come back to feed him, he flew down to them. It was then that I got to see him. And what a surprise – he was twice the size of his parents.

What happens next is hilarious. As bub is so big, the parents have to be careful when feeding, not to lose their head. On a couple of occasions they were a bit slow and had to extricate their head from Bub’s gob. Bloody funny to watch (unfortunately none of my photos worked out – so all in this post are from the internet).

How did a insect/nectar eater know to feed the baby Asian Koel meat?

So many questions. How much do we really know.

Nature - what a marvel!