I would suggest birds.
Chickens would love to work among elderberry bushes. They would keep things fertilized, debugged and not overgrown. The bushes would provide hawk and
owl protection. The elderberries would be too high up for the birds to get much. Anything that hit the ground though would be theirs. You might need to move them around a little so that the grass and clover could recover some. Fencing for birds is a lot cheaper also. Fencing ducks are easy, since they don't jump that well, trimming a wing helps keep them on the ground.
Ducks would work well also. They are less destructive, less like small velociraptors. I like their personalities a little better. For either bird, I find things work better if you have a male in the group. He keeps an eye out for trouble and the girls just seem happier. Too many males is a problem with ducks. They are way oversexed and will just wear out the girls if you have too many. 1 drake for 8-10 girls is good.
I haven't kept many turkeys. I think they would work well also. They would have a higher reach than a
chicken and might get some elderberries, but probably not too many.
Geese are another possibility. Once again, low hanging fruit might be taken, but elderberries are mostly up high. Geese are grazers and if you only have one they will adopt the chickens or ducks as their flock and help protect them. They can be aggressive though and that can be a problem if you have smaller children. I had a friend who raised geese and he told me
the answer for an aggressive goose was to hold it's body and neck to immobilize the head and have whoever was being hassled by the goose would stare it in the eye and repeatedly peck it with their nose, establishing dominance over that goose. He claimed it worked like magic. I haven't had a chance to test it yet, but am looking forward to trying it because it sounds hilarious and makes sense to me.