@nonayadambidnes Very cool and even cooler because that blue is prismatic; not from pigment.
Proof, take a Blue Jay, get it wet. Not blue anymore.
@nonayadambidnes yep, the feather structure scatters light such that blue is reflected. The pigment in there is brown.
@b4cks4w That is very cool. I'll have to check these guys when they're in the birdbath next summer and see if I notice the color change!