We recently did the same thing Leon. Bought a copy of Michael Morcombe's Field Guide to Australian Birds while on holiday. Sometimes find it quite hard to locate the right one in the book.
I'd be interested to see what else you have come accross in your travels.
Hi Leon,
With apologies to Jeff, I feel that the bird in your image is a Black Bittern.
Great image BTW.
Best.
Greg.
P.S. Leon, some advice re; the book Secure a copy of Neville Cayley's 'What Bird Is That', the paperback Field Guide will fit anywhere and is user friendly. An oldie but a goodie
I suppose it's thinking 'There used to be mangrove here.'
Leon, when you say ' a very large book on birds of Australia' do you mean a field guide or a coffee-table picture book. Picture books are lovely but you need a field-guide for ID. If it takes forever to ID your first birds, don't worry. Our first ID was the zebra finch. There were literally hundreds of them around a water tank, so we had no trouble seeing the markings. It still took us 45 minutes to work out what they were! Eventually I could ID them just by sound (not any more though). Initially of course it takes ages just to work out that it's a finch (or a heron or honeyeater or...) but once you're past that it gets much easier. You also get better at remembering and describing the markings. We found that his and her binos worked better than 'sharing' (ie arguing over) one pair (and of course the little bugger always flies off just as you are exchanging the binos.) Bird watching is great fun - and cheap too!
Hi Leon,
With apologies to Jeff, I feel that the bird in your image is a Black Bittern.
Great image BTW.
Best.
Greg.
P.S. Leon, some advice re; the book Secure a copy of Neville Cayley's 'What Bird Is That', the paperback Field Guide will fit anywhere and is user friendly. An oldie but a goodie
Sorry Greg but I think Jeff is correct.
A Black Bittern usually has brown legs not yellow. In addition a Black Bittern usually does not have the yellow flash in front of its eyes.
I use 'The Slater Field Guide to Australian Birds' Slater, Slater & Slater,
And 'The Birds of Australia' Simpson & Day.
I use both as often diagrams have slight variations in colour. ie cross reference.
Mangrove -Black cap, yellow legs and eye and lower beak. Also pattern on wings.
Not enought black to be a Black Bitten. Juv Black has similar pattern on wing but lacks the yellow colouring.
Thanks for your interest, and comments, the book that we bought is
"What bird is this" by Neville W Cayley. it clearly dose not name all birds of Australia as we have just seen.
First picture of a pretty common bird i expect, and it was not listed.
Hi Leon, and all the people who have so far posted.
I'd like to add my little piece in as well. The bird books mentioned are all good. I like the Simpson and Day, myself.
What has not been mentioned is that juvenile birds may look very different to the parents sometimes. To identify them becomes somewhat more difficult.
Be aware that it can happen. An example is the Pied Butcher Bird. I had a number of them visiting my back yard. (2 acres) One juvenile was brown while the rest were grey. After the moult they were all bright white and shiny black.
Bird watching is great fun - and cheap too! 
