Now since there are evolutionary advantages for deeper burial (I think). Then there is selective pressure for greater depth of burial. So after many generations of slightly increase of burial depth, the individuals who had slightly increase of physical activity to reach the surface would have a higher chance of surviving, thus having a higher chance to leave offspring.
Yes, that seems about right. As someone noted, in the early stages maybe the mother would assist.
I notice that all megapodes are born active, feathered, and even able to fly; apparently they dig their way out of the "nests" with large powerful claws. One wonders whether this precocious development is an adaptation to the egg-burying habit, or an exaption that allowed the evolution of the habit.
Interesting birds.
™ Version 4.2