Bait ball on the Hacking...

[khiemtran]

See this odd roundish plant at the bottom of the Hacking river?




Well, if you look a bit closer, you'll see it's not a plant at all...



It's actually a school of tiny fish!



Here you can see the school moving past the pontoon where Liem and I were fishing, just before it formed that plant-shaped formation by the shore.



And here they are forming a moon shape as they react to some disturbance behind them.

Comments

[mnfaure.livejournal.com]

I like the moon of fish. :D

[khiemtran.livejournal.com]

It was quite weird to watch it moving around the pontoon while we were fishing. The moon doesn't normally do that...

[puddleshark.livejournal.com]

Well, I was fooled!

But then I'm not a kingfisher...

[khiemtran.livejournal.com]

It was excellent mimicry. Although I expect a sharp-eyed kingfisher would see through it in a flash. We actually saw some kingfishers fishing yesterday on the Woronora, include one which caught a fish and sat on a branch with it flapping in its beak, apparently waiting for it to run out of air.

[duccio.livejournal.com]

Fascinating. I wonder if they have some form of telepathy?

[khiemtran.livejournal.com]

I did read an article once about formations of birds where they modelled the formations using a computer and found that just a few simple rules kept the whole flock moving together without colliding. It doesn't explain how they mimic a plant so well, but maybe there are simple rules for that too.

[zyzyly.livejournal.com]

Wow--that is amazing!

[khiemtran.livejournal.com]

It was! It was a privilege to see it up close. Better than a nature documentary. We also saw a stingray the same river and caught a little bream (too small to keep, so it went back).

[asakiyume.livejournal.com]

That's just amazing! They form such a perfect sphere in that first photo.

And going from a sphere to a crescent--they're doing both sun *and* moon.

[khiemtran.livejournal.com]

Yes, when they were a sphere, they looked exactly like a plant on the bottom of the river bed. Although if you looked closely, you could see tiny fluctuations as over fish moved through the ball.