Australasian Grebe brooding young on nest

I’ve recently made a couple of onservations of Australasian Grebe brooding young on their nest which don’t quite fit the HANZAB description: “chicks brooded on the nest for night of hatching and for no longer”. The grebes were at Tempe Ponds in the centre of Sydney very close to the airport. On my first visit on the evening of 10th there were chicks present being brooded by an adult on their floating nest – the occasional head appearing was the only evidence chicks present. I don’t know when they hatched but but at least 2 chicks were present. On my 2nd visit on the evening of the 15th again the chicks were being brooded by an adult on their floating nest. Another adult was diving nearby & when it brought food a chick would emerge, be fed, and then disappear out of sight under the brooding parent. I saw only 3 chicks simultaneously. On my 3rd visit on the evening of 18th, 5 chicks were swimming with adults being fed. Near sunset they returned to nest and again were brooded under an adult – although they didn’t entirely fit out of sight – perhaps because they were larger. HANZAB does elsewhere mention young using nest platform during first week with an adult so it may just be confusing wording. Anyway interesting behaviour to watch. I’ve put some brief video clips here: http://youtu.be/Oa-lo47p4J8 Andrew