My 7 month old retriever is coming along nicely and I'm planning on mainly hunting upland game with him. However certain things he gets very possessive with, and of course he loves birds so that is one thing he doesn't want to give up. He'll go pick up the bird and usually comes back to me with it but doesn't want to give it up. He is fine with things like a ball, bumper, or even bird wing. I've been trying to work with him to release on command but he'll only do it with a treat and something he's not afraid to give up. We've been working with trying to use another dead bird so that he sees that there are plenty more and he doesn't need to worry about just keeping that one, that seems to be helping a little. I also am trying not to push it and rip the bird out so a lot of times he'll keep the bird in his mouth and go back to hunting. Any suggestions would be appreciated. Thanks.