At 4:04 PM 96.10.30 +0800, wrote:
>Des Allen wrote :
>
>>I find this topic interesting. King et al (Birds of Southeast Asia) state
>>that the plumage of the Green Magpie (Cissa sp.) "changes to pale blue in
>>captivity, in ill health and after death." Why might this be? Also Dusky
>>Green Fulvetta (Alcippe cinerea) becomes dusky in the museum drawer (I
>>hear) but is much brighter yellowish in life. - THEY FADE !
>
>I don't know much about the Green Magpie, I guess the explanation depends on
>the degree of colour change experienced during "ill health" and after death.
> If it is subtle it could be due to whatever yellow pigment is in the
>feathers. Maybe they rely on a certain plant pigment which is hard to
>duplicate in captivity?
>
That was my guess too but I thought it was interesting that a genus
(family?) should have switched its 'preference' for making yellow from
refraction to a pigment.
>>>Lucas and Stettenheim (1972) Avian Anatomy - Integument, Parts I and II,
>>>Agricultural Handbook 362, Agricultural Research Service, USDA.
>
>This reference is very hard to get a hold of. It will answer some of your
>questions but will not provided sufficient info on UV reflectance. There
>is not much written on this subject in journals either.....
I floated this on BIRDCHAT but got nothing positive back, though one said
he would try with his friend's mineral prospecting gear.
>
>>>Also many parrots have feather pigments which fluoresce under UV light.
>>I'd be very interested to know what is known about the UV reflectance of
>>bird plumages. This could be important in understanding the taxonomic
>>status of allopatric forms - for example, the various island sspp of
>>Philippine Hanging Parrot but also Pittas etc etc. It might also tell us
>>how likely we are to be visible to the birds in ways in which we are
>>unaware. Perhaps aviculturists know more about this than birders.
>
>Can't answer all these questions. There was a short article on UV
>reflectance of parrot feathers (I think by Walter Boles) in BIRDS
>International several years back. This journal is now defunct and I don't
>know how you would get a hold of it.
Thanks - I'll try at tha Wild Bird Society of Japan's Research Loibrary.
>
>P.S. I don't think there would be many "aviculturists" that would know about
>feather pigments....
My thinking was that some people who kept birds might have tried 'black
lights' as a way of mimicking night, just as (I think) chicken farmers use
red light. They might have had there cagebird in the room when a
'blacklight' was on etc. More likely than a birder going out at night with
a 'blacklight' anyway, maybe.
>
> Does anyone have a reference to the sensitivity of the avian retina to UV
>light?
>
I remember reading an article, maybe in New Scientist, about how Kestrels
were sensitive to the UV reflected by vole urine, and when the poor voles
urinated in response to seeing the kestrel (or otherwise) they became more
visible. That is the only reference I have seen.
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