Very entertaining and interesting.
Most of your roosters appear out of the mold.....silver crest and what I call standard plumage.
In your third pic, last installment, a bird of another color appears in the upper right. No silver crown and he has what I call a golden hue, the chest feathers and shoulder patches not nealy as dark redish purple. I would say these are the second most common type, tho seen far less than your standard bird.
Two other variations often seen but hardly common are rusty colored, often with diminished markings, and very bronze breasted birds. I see one of these bronze birds about once a year, Hightail got one this year about 45 miles from where I usually encounter them. I skinned it then my dog ate the skin tho I have some partial skins from similar birds and have seen a couple at the taxidermist I use.
The saddles or lower back area of any bird can be gray, blue ,green or anycombo thereof. The depth and completeness of the ringneck can vary greatly having nothing to do with age. Likewise those crowns vary a lot more than you think if you look at them a lot.
I have even seen three birds with abluish tint to their feathers. They all came out of the same field but over a number of years. Did not see one this year.
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Suzuki Fr-50 History