I need your brains for my research

You seem like an intelligent bunch of people;- sensitive, well-read, mature (aw, get on with it-Ed). Anyway, I am currently researching an article on hunting and hunters for a commission. I am trying to find both historical and contemporary figures who were hunters who 'converted' to conservation. I already know about Aldo Leopold (Conservationist, philosopher etc) but I'd also love to hear your undoubtedly erudite comments on the subject. What makes someone turns from killing animals to saving them? Is it spiritual? Is it the result of a life experience which chages their perceptive or right and wrong, such as in The Deer Hunter?
Any feedback from you fine stable of fillies (and studs) will be gratefully read. Anyone read Leopold by the way? Interesting writing.