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Hi
Philip and others,
My
understanding is that while a lutino bird displays an excess of yellow a
leucistic bird is deficient in melanin in some or all feather tracts. For
example I found this on the web...
Buckley, P. A. 1982. Avian genetics.
Pp. 21-110 in M. Petrak (ed.), Diseases of cage and aviary birds, 2nd ed.
Lea and Febiger, Philadelphia. "Perhaps more loosely and improperly used than
any other term relating to color in birds, albinism is, no more and no less, the
complete absence of all pigmentation, resulting in white feathers (for the
reasons just discussed), pink eyes (no melanin obscures blood circulation, cause
of the pink color) and light bills and legs/feet. Albinism is all or nothing,
and a bird can no more be a 'partial albino' than a female mammal 'partially
pregnant.' ... What is most frequently termed albinism by the layman is properly
called leucism. It may be complete or partial, bilaterally symmetrical or
asymmetrical, and may affect melanins, carotenoids and porphyrins
differentially. Leucism is simply the complete loss of a particular pigment, or
all pigments, in feathers but not in soft parts. It may be as slight as a single
white primary feather on only one wing, or as pervasive as an all-white bird
with normal eyes, bill and legs" (p. 65).
In
birding circles it seems to have been commonly used in this way for at least the
last 20 years.
Regards
Rohan
By the description, I don't know that it is
leucism. It seems to be melanin deficient, rather than yellow
excess.
Philip
What
causes ?leucism? in birds?
There
was a leucistic Superb Fairy Wren at the You Yangs in Victoria last year
(possibly still there). It was a really amazing bird to see, and almost
seemed like a new species.
The You
Yangs is only 50km from Point Cook, so would environmental factors play a part
in the development of this syndrome?
Peter
Carol Probets
<>
Sent by:
01/06/2004 04:45 PM
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Subject
| RE: [BIRDING-AUS]
Mystery bird at Pt Cook |
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Almost 20 years ago I was regularly seeing a leucistic New Holland
Honeyeater in heathland at Mt Victoria (in the Upper Blue Mountains,
NSW). This bird was bright white all over, except for the normal
yellow on the wings and tail, and a faint smudge of grey around the
face where it's usually black. With this colour scheme the bird
almost
glowed. It seemed to interact normally with the other New
Hollands. I
still have a couple of slides of the bird which were
taken by a
friend.
As chance would have it, a couple of years later I saw another
similar bird at Katoomba (which is 15km from Mt
Vic).
Cheers
Carol
Carol Probets
Blue Mountains
NSW
100km west of Sydney
Rohan Clarke wrote:
>It is almost
certainly a leucistic New Holland Honeyeater that I
>found and
photographed near the last carpark at the beach BBQ area
>last week. It
has a black head and yellow patches in the wing and
>tail but the rest
of the bird's plumage is cream. When I get around
>to converting the
images from raw format to jpg I'll send you some
>record
shots.
>Regards
>Rohan
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