Date: 2/22/21 5:06 am
From: Edmund LeGrand <edmundlegrand...>
Subject: Re: [MDBirding] Digest for - 7 updates in 2 topics
The brightness of a male cardinal pales beside the handicap a peacock
carries around. One of the most insightful books I’ve ever read is Amotz
Zahavi’s
*The Handicap Principle: A Missing Piece of Darwin’s Puzzle
(https://www.amazon.com/Handicap-Principle-Missing-Darwins-Puzzle/dp/0195129148/ref=sr_1_1?dchild=1&keywords=handicap+principle+zahavi&qid=1613760457&sr=8-1
<https://www.amazon.com/Handicap-Principle-Missing-Darwins-Puzzle/dp/0195129148/ref=sr_1_1?dchild=1&keywords=handicap+principle+zahavi&qid=1613760457&sr=8-1>).*As
Zahavi explained, he came up with the concept of the handicap principle
when someone (Gordon Orians) pointed out that only a very fit peacock could
afford such a handicap. Hence peacocks show their fitness (to females, but
also predators) by sporting and supporting the extreme genetic precison of
the patterning and the bulk of the tail and surviving the associated
predation. For special abilities to be conveyed with credibility there must
be costs involved. (It’s easy to say “I can run fast”, but costly to train
hard enough to actually run fast, so that everyone can see for themselves).
The natural world (as well as our social world) abounds in examples. See
the concept of conspicuous consumption coined by Thorstein Veblen in 1889.
Male cardinals display their fitness both in obtaining the carotenoids to
make themselves red and in being able to avoid predators that are attracted
to them. This fitness pays off via sexual selection (by females), which
Darwin was the first to recognize.

Ed LeGrand
Hume, VA

On Fri, Feb 19, 2021 at 2:55 AM <mdbirding...> wrote:

> <mdbirding...>
> <https://groups.google.com/forum/?utm_source=digest&utm_medium=email#!forum/mdbirding/topics> Google
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> <https://groups.google.com/forum/?utm_source=digest&utm_medium=email/#!overview>
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> Topic digest
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> <https://groups.google.com/forum/?utm_source=digest&utm_medium=email#!forum/mdbirding/topics>
>
> - Coloration & survival in birds
> <#m_-8309011661358734340_group_thread_0> - 5 Updates
> - Pale Chickadee at Sycamore Landing - not leucistic?
> <#m_-8309011661358734340_group_thread_1> - 2 Updates
>
> Coloration & survival in birds
> <http://groups.google.com/group/mdbirding/t/f70c644e70015b8c?utm_source=digest&utm_medium=email>
> JAMES SPEICHER <jugornought...>: Feb 18 01:49PM -0500
>
> A novice birder friend has asked an interesting question:
>
> Explain to me why, under Darwin’s theory, an entirely bright red bird would
> survive down through the ages...
>
> Jim S
>
> ps 7 male & at least 5 female N Cardinals at the feeders this morning.
> Jim Moore <epiphenomenon9...>: Feb 18 02:02PM -0500
>
> Refer the friend to the fascinating award winning 2017 book by Richard
> O. Prum:"The Evolution of Beauty: How Darwin's Forgotten Theory of Mate
> Choice Shapes the Animal World - and Us".
>
> Jim Moore
> Rockville
>
> On 2/18/2021 1:49 PM, JAMES SPEICHER wrote:
> Scott Young <wsyacy...>: Feb 18 11:07AM -0800
>
> Excellent reference Jim.
>
> Also consider Natural and sexual selection act on different axes of
> variation in avian plumage color:
> https://advances.sciencemag.org/content/1/2/e1400155
>
> Scott Young
> Gaithersburg
>
> On Thursday, February 18, 2021 at 2:02:51 PM UTC-5, Jim Moore wrote:
> Walter Ellison <rossgull61...>: Feb 18 02:30PM -0500
>
> Hi All,
>
> Simply put if bright red males leave more offspring than much duller males
> they will eventually far outnumber the duller males. It's very likely
> females must preferentially select red males as mates. It's also possible
> that the shade of red we see is not what the cardinal's major predators see
> although I think it's likely the color must make male cardinals more
> conspicuous than females or females would be equally colorful.
>
> All the Best & Good Birding,
>
> Walter Ellison
>
> Chestertown, MD
>
>
> --
> Observing Nature is like unwrapping a big pile of presents every time you
> take a walk
> David Mozurkewich <mozurk...>: Feb 18 02:57PM -0500
>
> Good answers and I don't disagree but you also have to consider the
> other side of the coin -- the price for being brightly colored is not
> that large; in many situations, a brightly colored bird can be very
> difficult to see.
>
> Does anyone know of a good study testing this? Perhaps comparing the
> average lifespan of a male Cardinal to a female?
>
> Dave
> David Mozurkewich
> Lanham MD
>
>
> On Thu, 18 Feb 2021 13:49:26 -0500
> Back to top <#m_-8309011661358734340_digest_top>
> Pale Chickadee at Sycamore Landing - not leucistic?
> <http://groups.google.com/group/mdbirding/t/e74ceff02ab4236d?utm_source=digest&utm_medium=email>
> Scott Young <wsyacy...>: Feb 18 09:13AM -0800
>
> Recently, a pale chickadee (Carolina?) has been observed at the C&O
> Canal--Sycamore Landing hotspot by numerous birders, initially by Nathan
> Tea. Most have described it as leucistic, but in my preparation for a
> brief
> presentation to our club on bird coloration, I came to the conclusion that
> it is not leucistic. Instead, it most likely has the "Brown" mutation.
> This
> mutation reduces the amount of the black eumelanin in melanocytes without
> affecting the brown pheomelanin. The number of pigment granules and the
> number of melanocytes containing them are normal.
>
> It is clear that it is not leucistic as that phenomenon leads to lack of
> melanocytes and loss of all brown and black in those areas, either
> spottily
> or more generally. This chickadee has a universally brown cap and bib and
> not the appearance of all white or occasional white feathers within the
> cap
> and bib.
>
> Another consideration is the "Ino" mutation but that affects the
> pheomelanin as well as the eumelanin leading to a very faint brown.
>
> I received the suggestion that I mention this here to see if there were
> other thoughts and if there is agreement, then it would be appropriate to
> change the eBird descriptions to "Brown mutation."
>
> An example picture of the bird is here:
> https://macaulaylibrary.org/asset/308069661
>
> A good reference to color disorders by Hein van Grouw is here:
>
>
> https://static1.squarespace.com/static/52afb651e4b0c8fba4ecb28a/t/5c633ea3104c7b07ad5254a9/1550007979018/Grouw+Color+Aberrations.pdf
>
> Thank you.
>
> Scott Young
> Gaithersburg
> Gene Scarpulla <ejscarp...>: Feb 18 10:38AM -0800
>
> Scott,
>
> The Carolina Chickadee definitely does not have the color aberration
> 'Leucism' which would be characterized by all white plumage and skin
> ('100%
> leucism') or white feathers in only some regions ('Partial Leucism'). The
> Carolina Chickadee appears to have the color aberration 'Brown' where
> normal black becomes brown; normal brown becomes light brown; and normal
> reddish-/yellowish-brown remains normal.
>
> I have two short articles on this subject that will be published in the
> spring 2021 issue of *Maryland Birdlife*. One involves a House Sparrow and
> the other involves a Turkey Vulture, both with the color aberration
> 'Brown'. You might want to consider elaborating a bit more and publishing
> your note in *Maryland Birdlife*, as well. Feel free to contact me for
> further information.
>
> Gene
>
> Eugene J. Scarpulla
> Editor, *The Maryland Entomologist*
> Editor, *Maryland Birdlife*
> Bowie, Maryland
> ejscarp (at) comcast (dot) net
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--

Edmund K. LeGrand
14176 Hume Rd.
Hume, VA 22639
908-268-6627 (cell)

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