PhoebeFamily-feeding fledglings-part2.

This is another video clip of the 3 fledglings in the phoebe family near Canon City being fed by the one harried parent. If it looks like the larger appearing fledgling (at first on the right, then when the fledgling to it's upper left flies over it the fledgling is in the center of the three) is being fed more often than the other two, that is what I observed over a period of 5-10 minutes. Is this because it is more adept at opening it's beak wide or begging for food? SeEtta