> This morning I saw a flock of 22 R-t B-C s including one bird that at
first
> glance looked like a Sulphur-crested until I realised the jizz was wrong
and
> it had orange in the tail feathers! A strange looking bird with dirty
> white/grey plumage apart from the tail feathers . I had really good looks
at
> it - from about 15m and it flew right overhead a couple of times with the
> others. It was noticeable that a Black Kite was hassling it and not the
> others.
> I wondered if albino Red-tailed Blacks had been recorded before.
We had a similar thread run on Birding-aus about a year ago in relation to
another species which I now cannot recall. It was probably an aberrant
plumage called eumalanistic schizochroism seen in a number of species
(although in this case I suppose it could be an albino - did it have red
eyes?). A few months back I saw a Black Swan in the Colac area (western
Vic) that wasn't black at all - it looked very strange - and, no, it wasn't
a feral Mute Swan!
Schizochroism is apparently a term used to refer to birds which lack the
normal pigement whatever that may be; in the case of the eumelanistic type
obviously the melanin is in short supply. The question is what causes it
though - diet or genes or something else?
Susan Myers
phone: +61 3 9819 2539
Email:Susan Myers
Susan Myers
phone: +61 3 9819 2539
Email:Susan Myers
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