"A recent study in the journal Science, "Trophic Downgrading of Planet Earth," examines how the near disappearance of upper levels of the food chain—big cats, wolves, bison and great whales—has altered ecosystems around the world."
https://www.fastcoexist.com/1678282/humanitys-biggest-impact...
And more recently "... pups of predators in socially disrupted packs are more likely to prey on livestock."
http://www.publicnewsservice.org/2016-09-15/endangered-speci...