Hey, I think we have a robin fledgling here. At least that's what it looks like from googling it. Seems fairly big/mature (juvenile?) and so I thought maybe it was a female robin, but females don't look like that. And definitely flying with the robins. That's the best pic I got of it and the closeup is blurry.
Cornell has a pic of a fledgling. American Robin (Turdus migratorius)
NOTE: I'm noticing bird Families differ from place to place. American Robin: Muscicapidae vs Turdidae. Must not be a fixed categorization on those. I noticed that on Sparrows too.