I'm pretty sure that I know the answer for sure But ! If a couple of other more informed persons could confirm that would be good...
A landowner that I manage the deer numbers for takes out a few guns around his ground 3-4 times a season (they pay for the day)
one gun recently dropped a pheasant into the neighbours ground and the landowner jumped the fence to collect it (no gun or dog), the neighbours teenage daughter came out and was not happy about it !! Daddy came home from his day out down the road on a 500 bird day ! and promptly appeared at my landowners house telling him that he was never to enter his property again or he will be shot !!!!!!!!
I'm pretty sure you are not allowed to shoot your neighbours for picking up a dead bird but my landowner thinks he has a legal right to collect it , I told him its not so in regards to deer that's for sure and therefore not for game either.
A couple of posts to confirm this and I will send him the link to look at for himself.
Ps the landowner has actually done several favours for his relatively new neighbour and was in no way rude or arrogant when he went in to pick up the bird from what he has said.