Egg Sandwich
Posted by Niki Ellender on February 24, 2003
Q: Why is water important when a chick is developing inside its egg?
A: As an embryo develops, it does so within an aquatic (water) environment. Even baby humans develop within a water environment inside the uterus that is kept constant by the mother. Some of a chick's development draws upon the water within the egg (a bird is about 70% water) and the moisture surrounding a chick allows for the chick's rotation within the egg and the exchange of gases (oxygen in and carbon dioxide out) as well.
The references to moisture being necessary in incubators points out that without proper moisture, hatching success is greatly decreased. Hatching facilities are especially aware of this as they try to maximize their hatching success.
It's interesting to note that Mallard Duck females incubate their eggs for the last few incubation days by periodically wetting their feathers prior to sitting on their clutch. This marked increase in moisture appears to be important in providing the right environment for their eggs to hatch. So, even an outside environment is important to the chicks within each egg if proper development is to be achieved.
John Wiessinger ( February 25, 2003)