Last weekend I was surprised to see a European Starling in my North Seattle
backyard anting (rubbing its feathers) with Staghorn Sumac berries. I took
a short video after a quick web search didn't show any accounts of
Starlings behaving this way. I read that the berries have a high malic acid
content, and other bird species have been observed anting with them.

Sorry for the poor video quality, I didn't want to risk spooking the bird
by going outside:
https://youtu.be/tLdpJBx6nVc

-Max