Hi Ian,
There are plenty of birds around with black or other coloured beaks (eg
ravens, rainbow lorikeets etc etc) so of course a bird's bill can contain
pigment. There is no reason why genetic melanism should not affect the bill
as well as the feathers. I would expect oil staining to be obviously
blotchy and rub off long before a year.
Regards,
Pat
Patricia Macwhirter
Registered Specialist in Bird Medicine
Highbury Veterinary Clinic, 128 Highbury Road, BURWOOD, VICTORIA, AUSTRALIA
Ph: (03) 9808 9011 Fax: (03) 9888 7134
"A little wine - a little water. I'd rather speak to people than machines."
>This is a rather odd, and doubtless naive enquiry, but it may help to
>resolve a (mildly) raging debate among Canberra birdos at present. As you
>may know if you look at the Hotline Highlights, a black pelican has been
>hanging around Canberra lakes for most of the year. The debate centres
>around whether it is 'naturally' black, or oil-stained. The weight of
>opinion among observers favours the former, but a knowledgable member has
>just tossed in the following plausible argument for the latter.
>
>He argues that since melanin only replaces other pigment AND A BIRD'S BILL
>CONTAINS NO PIGMENT, the pelican's black bill is evidence of oil staining.
>With that given, he must be right, but is the proviso correct? I find it
>hard to accept that a bird's bill has no pigment, in terms of UV protection
>if nothing else.
>
>Would someone like to take a minute or two to sort this one out for me/us?
>
>Thanks in anticipation!
>
>Ian
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