It looks like one is clipped and the other isn't??
entrancedbymyGCC wrote:If I were designing this mode of reproduction, I'd make the egg stretchy and they'd stay inside another week or so! It is just amazing they survive. They must be amazing parents.
That's not the point though. You see some birds are altricial and others precocial. Precocial eggs are larger and the babies hatch more developed requiring less or no feeding/help from the parents. Altricial hatchlings (parrots included), however, require extensive feeding and metabolic support from the parents. Not only does this make the egg smaller, but it also requires less nutrients to be pre-stored in the egg. The most advantageous part of this all is that once the altricial chicks hatch, they can grow at a tremendously quicker rate and have the potential for greater brain development than their precocial rivals. Believe it or not the altricial system is newer and evolutionarily more advanced than the larger and more developed precocial one.