Here is a lengthy (~15 min.) video I took today while Bob was doing some panning and zooming. If you are ever on when this happens make sure you stick around. You can really get some nice shots and see the whole surroundings.
In this one Mom is sitting on the nest and she starts calling out for dad. Dad answers but doesn't come to trade spots. As usual she just takes off anyway. Later we find out she just goes to her perch on the limb to the left of the nest. Then we discover Dad is perched on a limb far off to the right. He still doesn't come. The egg is left sitting there uncovered for about 10 minutes while both parents sit on limbs on either side of the nest. Finally one gives in and sits on the egg.