But a comparable example might be cod, which have decreased in size 20% just in the last 3 decades, and mature much faster than they used to. Historically, they were huge fish, and even left alone don't grow nearly as large as they used to. Here's why.

Obviously commercial fishing is different from sport hunting, but I still think there should be some thought given to allowing certain very large individuals survive and pass their genes along in large numbers.

http://www.evolution-of-life.com/fileadmin/enseigner/05_human_made_evolution/en/KNOWLEDGE_Why_is_cod_shrinking.pdf