What bird call is this?

Hey guys!

Just really curious, what bird call is at 0:42 in this video attached? (http://www.youtube.com/watch?v=jPd8V9LFHlg)

The one that has a low tune and then a high 'weet weet~' , its call sounds like a whistled tune. 

I've been hearing this bird call really often - especially in the evening in Sydney. Usually around Kensington.

I really like this bird call, but I would really wanna know what bird is this!