This beautiful little bird can be found at the Williamstown Wetlands during spring and summer. When sunlit at the right angle you will see a wonderful iridescent glittering green on its wings. This contrasts against the barring on the chest and side. When shaded the bird appears duller.
Mature birds will typically perch in a prominent position to call and look for insects. The call is a descending whistle that can be heard persistently and from a long way off. 
The Juvenile Horsfield’s Bronze-Cuckoo is duller than the adult and also lack the barring on the underparts. Look closely at the below picture and you can see the diagnostic white eyebrow and dark eye stripe just starting to show.
Horsfield’s Bronze-Cuckoo’s are brood or nest parasites, in other words they lay their eggs in another species nest and let them incubate the eggs and raise the young.
Foster dad (Superb Fairy-Wren) feeding a juvenile cuckoo. Host species include fairy-wrens and thornbills.
For more information about this bird, see http://www.birdlife.org.au/bird-profile/horsfields-bronze-cuckoo.