lots of single combs in lavender Ameraucana hatch. Need to know why.

[key west chick]

I recently have hatched out 6 single combed lavender chicks out of 20. Thats nearly half of them. All parents have pea combs. I know it can occassionally pop up but doesnt that seem like more than just popping up? They are very pronounced singles too, not a mixture looking.

 

[phasianidae]

Quote:
Each of the parents where impure for pea comb (P/p+) therefore, out of 100 chicks you would get about 25 with single combs.