Flying around and teasing each other. It’s both feeding and playtime. They like flying at each other and getting another bird to leave that perch. Even when there are plenty of perches.
I think it’s a bird game similar to “king of the hill.” Our dogs play king of the hill. I’ve seen squirrels play it and sea lions, too.
Usually, when one Goldfinch changes color, they all change at about the same time. This year, a few have changed and some have already bred. Others, mere fledglings, are still pale, almost white or slightly grey. And most are still slightly olive. It was a strange winter. Kind of a non-winter, and I don’t know what will happen as we move through spring into summer.