I went back to the Lickinghole Creek and Reservoir and the adjacent Crozet Connector Trail to look for the Northern Flicker with red in its wings that I saw on November 19, and will provide an update at the end of this report. I ended up with 26 avian species, and a few good photos.
On November 19 at Lickinghole Creek , I got a few photos of a Northern Flicker showing reds and yellows in its feathers instead of only yellows.
Northern Flicker (November 19)
Northern Flicker (November 19)
Based on only one source (Sibley's field guide), I posted these photos as a intergrade between our eastern, yellow-shafted Northern Flicker and a western, red-shafted Northern Flicker. That posting resulted in emails informing me that newer research has shown that the ingestion of red honeysuckle berries could be the reason for the red coloring. Even though I have taken 700,000+ wildlife photos (mostly birds) during the past 12+ years, I am always learning, and am quite willing to entertain comments, questions, and other opinions, and change my thinking when presented with other information. I heard from two experts who had experience with this intergrade species, and both said that either intergrade or dietary-induced pigmentation were possible, and getting better head shots of this bird would help in the determination. So I went back to the same area on November 20, heard two Northern Flickers calling to each other, and got a very quick look at one of them flying overhead. This morning (November 24), I saw one of them at a good distance away, and got a few photos. I assume that it is one of the pair. Although the photos from this morning aren't great, it appears that this one is a male, and is totally yellow-shafted. If indeed, this is a mated pair, and one of them is the intergrade/dietary pigment bird, it must be the female with the interesting coloring. I will continue to look for these Flickers over the coming weeks.
On a related point, one person was critical of my posting showing a color comparison between of the November 19 photos and a red-shafted Northern Flicker that I photographed in Seattle, WA (within the intergrade zone) in August 2015. I wrote "Does the copper/salmon pink color look the same or different to you? Looks the same to me. Without a DNA sample, how can one know for sure?"
Crozet (left); Seattle (right)
That person wrote "Thought I should point out that making an I.D. based upon subtle hue variation in color photos is unreliable due to the numerous variables that affect color photography." I both agree and I disagree with this comment. First of all, a little information about my knowledge of digital images might help. I first started working with digital imagery in 1973, and by 1976 was developing algorithms for mainframe computers to process NASA digital satellite imagery of Earth and Mars. Given my long career working with digital imagery, I think it fair to state that I do have some level of expertise regarding digital photos. With my DSLR cameras, I shoot only 14-bit RAW images, and with all camera settings related to color enhancement set to zero. I color calibrate my computer monitor with a hardware colorimeter to ensure color accuracy. A 14-bit RAW image file can contain 16,385 colors per RGB channel, or more than 4 trillion colors. I picked one pixel from the salmon color of the November 19 image, and it had RGB values of 219, 125, 98, and a similar intensity salmon color pixel from the Seattle image, and it had RGB values of 217, 138, 94. In other words, there was less than a 14 pixel color difference in a 4 trillion pixel color space. And that's pretty close in color.
So what I am trying to say, is that the main difference between the same color in two images taken with a calibrated sensor is the result of ambient light, which can be quite significant. On one hand, that can affect species identification. On the other hand, color similarity is another clue in identification decision making, and should not be disregarded as unreliable. Otherwise, why even show feather color in bird guides - shades of gray would suffice.
The research on dietary influenced pigment changes clearly states that the pinkish colors are different from the salmon-pinks colors in the intergrade zone. So which of the following is more likely? The pinkish colors in the comparison photos above are different because one is intergrade and the other dietary influenced, and the combination of variation in ambient light and camera settings just happened to make the colors almost identical, or are the colors the same and the variation in ambient light made the colors slightly different?
So the hunt for an answer continues . . .