After my tune-up of 8 January 2009 [Happy Nude Year by the way] I thought "maybe I can hear them". I went to the park in the early-ish morning, a couple of times but couldn't tell if they were there or not.
Then I thought I'd heard the mascot Butcher-birds. I grabbed the camera and went scurrying up to the park to see if I could hear them, see them and record them. Yes is the answer and the result appears below. All made on a Mac.
The background is a bit noisy but when they sing they sing it out LOUD!! Be patient and you can see one of their silhouettes - they're difficult to see, let alone photograph! It's a bit shaky - I'll use a tripod next time. There were at least two having a good ol' sing-song.
I hope you enjoy it.