Something similiar in Acorn Woodpeckers. See:
https://thebirdersreport.com/wild-birds/portrait-of-the-juvenile-acorn-woodpecker
---
Rusty Scalf
On 2020-06-19 17:52, Gerald Meenaghan wrote:
All,
I think Sarah Sloan's explanation based on her experience with bushtits makes
sense. That is, this is likely a short-lived developmental change in iris
color rather than a genetic mutation. That would support my review of photos
of pileated woodpeckers in the Macaulay Library. Only ~1% of PIWO photos
depict a blue-irised individual. Add filters for "juvenile" and "immature,"
and it rises to 10-20%, with another large percent having some variation of
dark or not-quite-yellow irises. This would represent the development from
immature to adult bird, from dark to light yellow iris, with blue being
somewhere in between.
Thanks to Sarah Sloan, Noah Stryker and Martin Stervander for their messages
supporting this. Martin adds, "I don't think there's any reason to believe
that blueish eyes in birds would necessary reflect a recessive trait that is
being expressed in a homozygote for that recessive allele!"
It's interesting to note that, at least anecdotally, this is true of certain
human populations as well. Human babies are known to undergo iris color
change in their first year, with the color solidifying around age 1.
Gerry Meenaghan
Eugene, OR 97405
541-221-4307
On Jun 19, 2020, at 5:35 PM, Sarah Sloane <sloane@xxxxxxxxx> wrote:
Yes. That's my thought. Female bushtits go through that stage before
finally getting the adult eye color at about 3 months.
But pileateds aren't my area of expertise, so I could be wrong!
&&&&&&&&&&&&&&&&&&&&&&&&&&&
Dr Sarah A. Sloane
Associate Professor
Dept. of Biology
Division of Natural Sciences
University of Maine at Farmington
Farmington, Maine 04938
sloane@xxxxxxxxx
207-778-7484 (office)
207-500-3733 (cell)
https://bushtitsrule.blogspot.com
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On Jun 19, 2020, at 5:33 PM, Gerald Meenaghan <meenaghang@xxxxxx> wrote:
Sarah,
Thank you for your response. I think this is it. It's a developmental stage
rather than a mutation. What you're saying is that all PIWOs likely go
through this, but it is a short period of time and this accounting for only a
small percentage of the PIWO photos I sorted through, even of those marked
"juvenile" or "immature." Rather than it being a certain portion of all birds
who experience this, you're saying that it's likely all birds who have blue
(or some other version of light) iris coloration on their way to the adult
bright yellow? So, basically, I photographed this bird in its very
short-lived "blue iris" phase, and that next month (or a bit later) its eye
color might be yellow? Is that closer to the mark?
Gerry Meenaghan
2934 Mill St.
Eugene, OR 97405
541-221-4307
On Jun 19, 2020, at 5:26 PM, Sarah Sloane <sloane@xxxxxxxxx> wrote:
Are you sure the blue-eyed pileated isn't a juvenile of the year? Female
bushtits hatch with dark brown eyes and the iris changes to cream or yellow
very slowly. It passes through a gray-blue stage that looks very much like
the iris in the picture.
Just a thought.
Sarah
&&&&&&&&&&&&&&&&&&&&&&&&&&&
Dr Sarah A. Sloane
Associate Professor
Dept. of Biology
Division of Natural Sciences
University of Maine at Farmington
Farmington, Maine 04938
sloane@xxxxxxxxx
207-778-7484 (office)
207-500-3733 (cell)
https://bushtitsrule.blogspot.com [1]
&&&&&&&&&&&&&&&&&&&&&&&&&&&
On Jun 19, 2020, at 2:35 PM, Gerald Meenaghan (Redacted sender "meenaghang"
for DMARC) <dmarc-noreply@xxxxxxxxxxxxx> wrote:
Oregon / Lane Birders,
This morning, John Sullivan and I had a really nice experience with a pair of
pileated woodpeckers at Wayne Morse Ranch in Eugene. Upon my return home, I
processed my pictures to find that the male (redhead) has blue irises. At
first, I just thought it was cool-looking, but after a cursory Google image
search, I'm finding it's quite rare. Another cursory search on eBird's
Macaulay Library indicates that it's perhaps ~1/100, making it about as
common as red hair in humans. Yellow irises are the norm, with dark (orange,
brown) irises being the next most common. Does anyone have any leads on the
prevalence of this blue iris recessive gene expression in pileated
woodpeckers? Basically, how rare exactly are blue irises on a pileated
woodpecker?
I've attached one small example picture here. More can be found here:
https://ebird.org/checklist/S70601778 ;
With thanks in advance,
Gerry Meenaghan
meenaghang@xxxxxx
541-221-4307 <Blue-eyed redhead7.jpg>
