Fences

In 1874, Joseph F. Glidden, an Illinois farmer, patented the type of barbed wire still used today. Within less than a century this "improvement" for the keeping of domestic animals completely disrupted the natural migration paths of wildlife worldwide.

Hunting

Human nature dictates that we discard what is not needed. Up until the early 20th Century, wildlife was being slaughtered wholesale to make room for the ever-increasing human population; the hunting community in large part gave wildlife value again, therefore saving many species from eventual extinction.