Birds changing gender

["Greg" <>]

Hi Andrew,

Some years ago while bird banding at Tumbi Umbi, on the Central Coast of 
NSW, I retrapped an adult female Golden Whistler that was assuming male 
plumage characters.  I knew that it wasn't an immature male assuming adult 
plumage as the bird was very old (for a small bird) at the time and had only 
recently began assuming these characters.  Its banding and retrap history 
was recorded on a specially designed card.  John Disney, who was the Curator 
of Birds at the Australian Museum suggested that it was probably due to the 
deterioration of the ovaries due to age.  I think that the XX (female) 
chromosomes become XY (male).
So this phenomenon has been known for some time.


Regards

Greg Clancy