Raft of birds

Hello Robin,

Your birds were almost certainly Hoary-headed Grebes. Flocks of thousands are well documented in HANZAB.

There is a not very good pic on my website of one of these rafts I took many years ago on the Coorong. www.graemechapman.com.au/library/viewphotos.php?c=225

The fact that they were accompanied by gulls and the odd cormorant suggests to me that they were feeding. Other species form large rafts to round up food, pelicans, Banded Stilts,
Pied Cormorants and Little Black Cormorants to name a few. The best example of this sort of cooperation I’ve ever seen was at Longreach Waterhole in the NT a couple of years ago where there were several thousand pelicans present.Twenty or so birds would form a tight circle around their prey (presume fish) and on a given signal (there would have been one) it was DIVE! DIVE! and they all dived, perfectly synchronised.

Cheers

Graeme Chapman