The hippopotamuses left behind at the estate of slain drug lord Pablo Escobar have been described as “invasive species” in Colombia’s lakes and rivers. After police killed Escobar in 1993, four hippos escaped from his private zoo and multiplied into a population of 80 to 100 animals. Local people avoid the very dangerous beasts, but oppose proposals to destroy any of them. Waste from the four-ton vegetarians is polluting the water and causing algae blooms and fish die-offs.
Class discussion: What is an invasive species? What can they do to local environments and native species? Hippos kill 500 about people a year in their native Africa – twice as many as lions. Should Colombia’s hippos be killed to protect the local environment? Why or why not? The hippos are the largest wild animals to roam the Americas since arrival of another invasive species killed off all the mammoths, giant sloths and other large American mammals about 12,000 years ago. What was that species which is also the world’s top predator?