Sorry about the camera shake, trying to lean over the kitchen sink, without scaring him off....
Popped a video of him feeding on youtube you can view it here www.youtube.com/watch
He has clearly found a way to eat. Maybe it scoops up seed with the lower mandible? Preening must be a challenge though.
Unicum arbustum haud alit duos erithacos
(One bush does not shelter two Robins)
Zenodotus (3rd Century B.C.)