Shining cuckoo: Suggested by fan Barbara Zerzouri as they're all around Wellington at the moment and there's a great waiata by Maori composer Hirini Melbourne about the bird.
The shining cuckoo is a 'brood parasite' - it puts its eggs in the grey warbler's nest and gets them to bring up their children. When it hatches in the warbler's nest, the chick pushes the warbler eggs/chicks out because nature.