Naturalists have known for decades that the Iguana, a New Zealand reptile, is endangered on the southern islands  But because the southern island Iguana and the northern island Iguana are thought to be the same species, they are not extinct  But because the southern island Iguana and the northern island Iguana are considered the same species, there is no need to protect them   However, New research suggests that the southern island Iguana is a unique species found only there  Because it's now known that if the southern island Iguana goes extinct, the species will go extinct
A regional extinction will not force people to do their best to prevent it. A global extinction will force people to do their best to protect it.
 So people had to keep them from going extinct, even if that meant killing many of the natural predators that fed on them without the risk of extinction