When my 13 month old lab was 8 weeks I tried him on dove wings and darn near didn't get on back...had to pull it out of his throat. Now that he's bigger and he's on full size ducks he still doesn't want to give them up. He doesn't growl but he acts like he'd prefer to eat it than let me take it. The retrieve is no problem.....he comes right back to me with the bird just as fast as he can but when he gets to heel he either lays down to "chew" on the bird or he thrashes his head around as if to keep it from me. He doesn't do it all the time....sometimes he gives the bird up readily. To be honest he was the same way with bumpers to some degree....just not as bad as with birds naturally.
He has NOT been through force fetch although I am open to doing so if it will help. Did I answer my own question? A dog properly forced will give up the bird whether he wants to or not?
Is this something I can repair with repeated exposure to birds whether I force train or not?