I have raised these 4 ducklings from eggs which are now 7 weeks old. Their parents are an all white Pekin momma and a black/green Cayuga papa with white chest flecks. There appear to be 2 colorings. There are 2 brown feathered ducks with yellow feet, one somewhat darker than the other. The other two are mostly black with white check flecks but already have dark green heads. If I didn't know better I would say the kids are Rouens. It's unlikely the Pekin bred with a mallard or Rouen as I got them (from the same flock) when they were sexually immature well before she started laying eggs or the male went green. They were also quite "active" before brooding (which the Pekin did all by herself). Anyone have a similar experience? I suppose the mallard genes could be recessive and came out in the ducklings. Also any guesses on sex? They stick together so hard to tell their quacks apart though the bigger paler brown one is probably a female on that basis. Here are some pics.