Kereru breast colouring

[Midgimoo]

I have three kereru in my garden and have been wondering about their colouring. I see differences in the 'length' of the adult birds colourful necks, and wonder which is the male/female - any idea?

But, it's the photos (on the net) I recall seeing of some kereru with bronze feathers on their necks. Neither of the two adults, nor the youngster in my garden have this bronze colour, and it's got me baffled. Is it a different strain or perhaps a Nth/Sth Island thing?

Any ideas much appreciated

[David Riddell]

I remember in Geoff Moon's classic book 'The birds around us, New Zealand birds, their habits and habitats' (1979), he had photos of a pair of kereru feeding a chick at a nest. Both were photographed within a short space of time, sitting at almost the same angle and in the same lighting conditions, and one bird had a distinctly bronzy breast while the other's was green. So probably not a North/South thing, and I've never heard that it's a male/female thing either, though others may know more. Don't have the book on me, so I'm going on memory.

[Midgimoo]

Thanks for your reply, David. I must see if I can get the book you mention from the Library.

[Nick Allen]

At least part of the green colouration will be due to light diffraction (I believe turacos are the only type of bird to produce an actual green feather pigment), so maybe the light was hitting the feathers at a slightly different angle?

[David Riddell]

Yes I think you're right Nick, and the "bronziness" is mainly iridescence I think, which also varies a lot with light angle. But as I recall the Geoff Moon photos showed quite a striking difference in two very similarly posed birds - he commented on it in his captions, and presumably observed these birds over a period of time, so I suspect there's a degree of individual variation in the bronzy iridescence.

[Midgimoo]

Thanks guys. I look forward to getting my hands on this book.
My young kereru continues to delight me each day. I live in a two storey house and have extensive woodland garden. Yesterday morning he was perched in an ancient kowhai watching me brush my teeth I had to rush down stairs and get the camera - got an interesting pic of him.