Ash-red cockbird question

[MaryOfExeter]

I noticed this a while back but forgot to ask about it
I've got a pied red check bird, and it's very obvious it is carrying blue. But there's one thing on it that I haven't seen before. It has one blue bar tail feather. Now I know they're supposed to have blue FLECKS, but a whole feather, with the bar and all?? Is that normal?

I'll get pics later, as I'm off to a chicken swap!