This is a common bird who follows gardeners in NZ and digs into the garden.
There was a certain Blackbird who used to watch Mum did her banana peel into the garden. As soon as she left the Blackbird dug it up again. So Mum would bury it again and the Blackbird would dig it up again.
Mum was quite amused by this bird. I often find them following me when I pull out weeds. Its as if they say, do gardening so that I can dig up more bugs to eat.
Its a wonderful bird. The males are black like this one and the females are brown. The fledglings are brown and speckled.
I believe the ancestors of this bird were from England. Its not a native of NZ. It does no harm to the environment. Actually improves it.