Old enough for fertile eggs?

[bernie131]

My drake is 4mths old and I saw him try to mount his Mom(pekin) and she has been laying eggs for about 1mth but no bulls eye on the eggs. My question is how old is old enough for my drake to be fertile and how soon after seeing mating behavior would I have fertile eggs? My drake is the pekins son and he is half Mallard and is he going to try to mate with his sister also born the same time? Does this behavior go on all year?

 

[sourland]

If he consummates the deed, the eggs will be fertile within two or three days. If hens are laying and willing drakes are up to the deed.