Hunting advocates and various fish and game bureaus argue that hunting is an effective and needed means to control various species and manage wildlife. One such claim says that "hunting benefits all wildlife" and that:
Scientifically-based and regulated hunting has never led to threatened or endangered wildlife populations, ever!
I think "regulated hunting" is a pretty clear term. I'm not sure what "scientifically-based hunting" is, but I think it's safe to assume some empirical data is involved. I would expect "scientifically-based" anything to look a lot like legitimate science with lots of observational data correlated to various activities and actions.
Considering the complexity of any ecosystem, I have a hard time believing that all hunting (wildlife harvesting) schemes done with conservationist intentions, even based on scientific data, have never had unintended negative consequences. However, the claim specifically says threatened and endangered populations, which is pretty strictly defined in a scientific sense. The claim may just be hiding behind a strict set of definitions. If the claim is strictly true, has it ever come close to that?