Crimson Rosellas Platycercus elegans about, quite a bit of argy bargy seemed to be going on, though it isn't breeding season so I'm not sure why!
Botanical garden facts on the genus, "Grevillea is named after Charles Francis Greville who was one of the founders of the Royal Horticultural Society in 1804. There are over 300 species in the genus, most of which are endemic to Australia but a few species occur in Papua New Guinea and islands to Australia's north".
Having now read the ANBG weekly update on what is in flower, I've deduced that the yellow flower is probably Acacia subulata.
As I was leaving, a little flock of Choughs Corcorax melanorhamphos were hanging around the gate - they are lively little fellows, although boldly coming right up to glare at me with their red demonic eyes it was hard to get a good picture. Although sinister looking they are really quite inquisitive friendly chaps: