Are Carnivore Reintroductions Always Beneficial To An Ecosystem?

Apr 9, 2019

A new research paper finds that reintroducing carnivores in an area does not always mean there will be positive effects to that ecosystem. The long-held assumption was tested by a group of ecologists that looked at different carnivore reintroductions and removals around the world.

Jesse Alston, a Ph.D. student at the University of Wyoming and one of the authors of the paper, said a successful reintroduction would mean a decrease in prey and an increase in vegetation. This was seen in Yellowstone when wolves were reintroduced. The number of elk decreased and aspens and willows increased.

But he said, it turns out, it's not so simple. One example is when African wild dogs were reintroduced to a part of Kenya.

"The wild dogs reduced the number of their major prey and increased the number of plants," said Alston. "But when they compared that to a control plot where wild dogs were not reintroduced, they found the same thing happened."

Alston said this mean you always have to dig a little deeper to really see what's causing the change since sometimes a reintroduction can have the opposite impact. He said scientists need to research more questions like: "In what situations do we get certain phenomenon? So, it may be certain types of large carnivores that have more regular effects than others."

He hopes other scientists will ask these questions as well.