tails

This one is a little fuzzy. He was not happy with me taking photos today. A little better My favorite of the 3

I was looking at my JD juvis today and noticed that some of them are developing red spots on their tails. Its not illness, the spots are evenly spaced and match the iridescent spot pattern. I only see it on a few of them. I did a google search and came up with nothing. Possibly just a...