The [fledgling] house finches are the most graceful of the bunch -- and I use the term loosely -- presumably requiring less landing space, but even so, they'll land on the feeder and continue to flap madly for a few seconds -- "Am I down? I don't know if I'm down! OHGODIFISTOPFLAPPINGILLFALLINHOTLAVA!"* -- before finally settling and discovering that their feet are, indeed, capable of holding them to an object.
* I'm extrapolating from my own childhood here. It's possible birds don't play "hot lava."
The tufted titmice are younger than the others, and not yet adept at feeding themselves, so they stomp around the deck, doing the rapid-wing-vibration thing and shrieking to be fed. Somewhere an adult titmouse is counting to ten and massaging its temples.