Here he is now. Or rather, last week. Still cute, but the awwww factor has mostly been replaced with I can't stop looking at that crazy thing on his head.
When we ordered our ducks from Ideal Hatchery, I noticed the statement, "Crested Fawn and White Runners may possibly be included with your order." None of our ducklings were crested though, so I forgot about it. But one must have carried the gene.
According to the Domestic Waterfowl Club of Great Britain, "The crest is a mutation associated with skull deformities... The crest is formed from a mass of fatty tissue that emerges through a gap in the cranium (skull). From this, feathers grow."
The crest gene is an incompletely dominant one. ie, if an chick receives a double dose of the gene - one from each parent (homozygous) it will die in the shell. If only one of the parents passes it on (heterozygous) the resulting hatches will be : 25% will not hatch, 25% will not have crests and 50% will have crests. If a crested heterozygous bird is crossed with an un-crested one, the resulting hatch should be 50% crested and 50% plain.
Bluebill started sitting on eggs just after the Easter week freeze, so only the eggs laid that morning had a chance anyway.