Loading...

bcintbird-pics@googlegroups.com

[Prev] Thread [Next]  |  [Prev] Date [Next]

RE: bcintbird-pics Colour factors and moult - delete now if you have had enough of Grosbeaks Rick Howie Tue Feb 21 09:00:47 2012

Thanks Barry.  Herewith endeth the parable.

 

Rick 

 

From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of M Lancaster
Sent: February-21-12 12:54 AM
To: [EMAIL PROTECTED]
Subject: bcintbird-pics Colour factors and moult - delete now if you have
had enough of Grosbeaks

 

OK - moult and 'red feathers'.

 

It is perfectly possible to have red, yellow, shades of red, shades of
yellow, and feathers with red and yellow in them ALL as part of the same
moult, OR, indeed, feathers without any of the said colours. Hence for
example, black or grey feathers in the Pine Grosbeak.

 

Firstly, the red/yellow complex ( in most species of birds) is derived from
eating foods containing precursors to aforesaid red/yellow complex.

 

Secondly, feathers are moulted feather tract by feather tract.

 

Thirdly, each tract is programmed to produce feathers of a certain type and
colour.

 

Fourthly, growing feathers takes time.

 

So, even if a feather tract was supposed to 'turn' red, if the bird did not
have access to precursors, or have a store in the body (see below (1))
feathers could be of different colours and especially those that take weeks
to grow, could even exhibit differences of shade or even absence (of colour)
in the same feather.

 

Normally, apparently bizarre appearances would not occur of course - but it
is possible.

 

Then, one has to consider sex (gender not act). Female Grosbeaks do not
normally appear red (if at all?) so they are eating the same precursors as
the males and not (I guess!!!!) having the same 'magic ingredient' as males
(that produce red)  and only produce yellow (or shades thereof and
occasionally reddish - 'bronze' is a term used  - see below (2)). 

 

That said, it is perfectly possible for a male to have yellow(ish) feathers
in varying amounts and especially if it is a young male - indeed the common
consensus is that first year (of LIFE) Pine Grosbeaks look like females yet
in the second year (of LIFE) therefore 1/2 calendar and 2/3 calendar years
they appear as 'males'. What is more, generally speaking the amount and
intensity of 'redness' does increase somewhat as male birds age ( and I have
speculated this could occur with females also).

 

OK now for the difficult stuff :-), and another species (or species). For
about 25 years I was an aviculturalist  and associated with others who bred
many different species of birds in captivity - I mainly confined myself to
psittacines. However, by association and research and post mortem I learned
a few things about 'colour fed' birds and indeed at one time I was breeding
the ubiquitous House Finch. Colour has a major impact on the so called 'Red
factor' Canaries which arose as the result of a hybridisation between the
Canary (Serinus canaria - yes, from the Canary Islands) and the Red Siskin
(Carduelis cucullata) from South America. Canaries without Red Siskin genes
and without access to natural foods or manufactured 'red colourants' cannot
produce red feathers - yellow, yes, because that process is part of the
original Canary gene package. Hence, the average perception that Canaries
are yellow - sorry folks, not wild ones.

 

House Finches kept in captivity also need access to natural foods or 'red
colourants' before males will exhibit red feathers. NB females eating food
or drinking water containing 'red colourants' do not have red feathers. It
is perfectly possible to see House Finches in the wild with yellow feathers
where red should be.  If my experience with captive House Finches is worth
anything, these are probably birds in their second calendar year.

 

Now, nobody seems to know just how much (colour)-food or how much powder
should be added to food or drink in order to facilitate a red appearance of
Canaries. This must be provided before and during the period of moult.Too
much colourant results in the appearance of what is termed 'burnt' birds
which are a reddish bronze in colour ( see above 2). Such birds can and do
produce red feathers in a succeeding moult (or moults ??) as the result of
the 'red colourant' being stored in fat - post mortem shows birds with
bright red fat (see 1 above). I doubt if this occurs in the wild.

 

So, given the right or wrong conditions almost anything can, and does happen
- ain't nature wonderful?

 

For those who have not had enough of this subject, I suggest one 'Googles'
Carophyll Red - there is also a Carophyll Yellow. Also 'Google' carotenoids
- Birds of North America offers a short discourse pertinent to Pine
Grosbeaks.

 

Barry

 

M B Lancaster,
Currently - Tenerife, Islas Canarias

----- Original Message ----- 

From: Rick Howie <mailto:[EMAIL PROTECTED]>  

To: [EMAIL PROTECTED] 

Sent: Tuesday, February 21, 2012 1:07 AM

Subject: RE: bcintbird-pics grosbeak identification

 

High again Phil. It is a curious phenomenon in that by the time this bird
had moulted in all of those red feathers, the rump feathering should have
followed suit as the molt is normally complete. It appears as if there can
be aberrant individuals whereby some feathers forgot to fly away and make
room for the new inbound ones. A constant reminder that nature retains the
right to variation for whatever reasons and purposes. 'tis perhaps only
humans that make rules and then expect everybody and everything to obey
them.

 

Perhaps Barry can enucleate the reason for such variation which we shall
entitle " Lancaster's Molt Parable." 

 

Rick Howie  

 

From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Phil Ranson
Sent: February-20-12 1:54 PM
To: [EMAIL PROTECTED]
Subject: Re: bcintbird-pics grosbeak identification

 

I haven't been following the particulars of this discussion, but thought I'd
throw in a recently taken photo by Rod Sargent at Baker Creek west of
Quesnel. He was intrigued by the mustard rump on an otherwise typical adult
male plumage. 

 

Phil Ranson

Williams Lake

-- 
You received this message because you are subscribed to the Google Groups
"BCs Interesting Bird and Nature Pictures" group.
To post to this group, send an email to [EMAIL PROTECTED]
To unsubscribe from this group, send email to
[EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/bcintbird-pics?hl=en-GB.

-- 
You received this message because you are subscribed to the Google Groups
"BCs Interesting Bird and Nature Pictures" group.
To post to this group, send an email to [EMAIL PROTECTED]
To unsubscribe from this group, send email to
[EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/bcintbird-pics?hl=en-GB.

-- 
You received this message because you are subscribed to the Google Groups
"BCs Interesting Bird and Nature Pictures" group.
To post to this group, send an email to [EMAIL PROTECTED]
To unsubscribe from this group, send email to
[EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/bcintbird-pics?hl=en-GB.

-- 
You received this message because you are subscribed to the Google Groups "BCs 
Interesting Bird and Nature Pictures" group.
To post to this group, send an email to [EMAIL PROTECTED]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at 
http://groups.google.com/group/bcintbird-pics?hl=en-GB.