In spring 2011 my then 1 year old pair of Blue Head Australian Spotted bantam ducks hatched five eggs. One male blue head, one male green head and one female green head survived. Of the two other eggs one silver head duckling hatched overnight (I never saw it) and was dead in the morning and lastly another silver head hatched then died on the fourth day. Spring ahead to this week. One blue (I think) head and one silver head hatched. The silver head was slower than the other one and today on day four I found it dead. The third duckling died in the shell while half hatched. I believe it was a silver head as well. I'm now suspecting that with this particular mating pair (Bo & Bella) there is a lethal gene affecting the silver heads. I don't know much about genetics so I could really use some information so all the silver heads don't keep dying. I don't know if its a specific gene that is causing the deaths or would bringing in another male stop it?