My children and I always enjoyed seeing the same two ducks at the lake. We could spot them a mile away due to the pouf of feathers on top of their heads. Were they just having a bad feather day every day? No, they were born like that. They are what is known as crested ducks.
In crested ducks, the crested gene is a genetic defect. According to backyardchickens.com, the crest (or what I call the pouf) is actually fatty tissue covering a gap in the skull. Oh my! Breeding crested ducks is considered cruel by many as the chance is greater that the chicks will die in the shell due to this genetic defect. If bred, the chicks have a better chance at survival if one parent does not have the defect.
I never knew this before. Sometimes it is worth the while to look up things one is curious about. It could lead to a new appreciation or understanding of a subject. Defect and all, these crested ducks will always have a place in my heart.