I realize this reply is over a year after the original question, but I now have actual, factual information to share! YES, broody hens can and DO successfully hatch out turkey eggs. I allowed 4 of my hens to remain broody this year, only robbing them of chicken eggs and placing turkey eggs under them instead. The hens don't care that it takes an extra week before they hatch because by the 21st day (when chicks would normally hatch) they are so committed to the nest, there is no way they would leave until those babies hatch! They are super protective mothers and even though their "babies" are larger than their chicken counterparts at the same age, the mother hens take care of them just the same. I have noticed that the poults (the baby turkeys) don't come running when the hen calls them for food quite as quickly as chicks, but I think it's because turkeys are just more "chill" than chickens. My current group of poults is about 5 weeks old. One evening last week the hen called them in to the coop with the rest of the chickens (I had kept them in a separate, small coop to begin with) and ever since then they have started roosting with the rest of the chickens. I've had much greater success with hatching turkeys under chicken hens than I have had allowing turkeys to hatch their own.