culling is neccesary due to having no natural predators anymore.
when people who have no understanding of these things get involved the results can be catastrophic for the animals.

one particular case was when paul macarteney bought a wood in devon then fenced it in to keep the deer in so that the stag hounds couldnt hunt them. the end result of that little escapade was the deer bred and litteraly ate themselves out of house and home. this resulted in all the deer being emaciated and quite a lot died of starvation. for centuries there had been a sustainable deer population in that area all fit and healthy. but because macarteney is anti hunt he caused unnecasary suffering on animals because he is ignorant of life in the country.