Tui, endemic to New Zealand, are boisterous, medium sized, common and widespread birds of forest and suburbia. They look black from a distance but in good light tui have a blue, green and bronze irridescent sheen and distinctive white throat tufts (poi).
Adults have a notch on the 8th primary feather and this feather quivers from the narrow part creating the whirring sound common in flight. They have a noisy unusual call but can also replicate human speech.
Tui are notoriously aggressive and will defend a flowering or fruiting tree from all comers. They vigorously chase other birds away from their feeding territory.
photo from blog.tepapa.govt.nz
Photographer Tony Whitehead