Just be aware that if you put them on craigslist, you cannot guarantee that the person that is taking them is not going to eat them.
Are there any animal shelters near you that have facilities for farm animals? You may need to pay a small surrender fee, but if you truly care about them, it is worth it to know that they will eventually be placed in a good home, or live their life out there safely.
All my ducks have been adopted from the MSPCA in Methuen, MA. (Well, I did get one from a friend, but the other 6 and the 2 I am getting today are from there)
Good luck.