Cross Breeds

How can birds and other animals that are hatched survive?

When humans have children, they are nurished through the umbilical cord. And other animals who carry their children til birth are also nurishing the babies. How can an animal being hatched from an egg survive til birth? They aren't getting any nurishment from the parents, only warmth from them sitting on the eggs. Just wondering.

Public Comments

1. Inside the egg, is a yolk sac which serves as nourishment for the chick..like an umbilical.
2. Unknown to a lot of people, the baby bird or reptile is not "made" of the yolk. They are attached to the yolk and the yolk feeds them. It is the animal version of a human Placenta. They usually don't even need food for 24-48hrs after hatching as they still have nourishment from the yolk in their system. Here is a basic websites you might like http://en.wikipedia.org/wiki/Egg_%28biology%29