What is extinction? The answer is complicated.
From locally extinct to functionally extinct, here are the various ways scientists track species’ decline.
Extinction is a natural phenomenon: After all, more than 90 percent of all organisms that have ever lived on Earth aren’t alive today.
But humans have made it worse, accelerating natural extinction rates due to our role in habitat loss, climate change, invasive species, disease, overfishing, and hunting.
“We’re losing whole suites of species that have distinct ecological roles to play,” says Stuart Pimm, Professor of Conservation at Duke University. For instance, top predators such as sea otters and sharks have dwindled, throwing their ecosystems off-kilter.
The main body that tracks species decline is the International Union for the Conservation of Nature. The organization evaluates species in the wild, and, along with data from a variety