Extinct Niches

Although hippos aren't native to South America, there is a thriving population of around 80 hippos thriving in Colombia’s lakes and rivers. Some are worried the population could grow big enough to overwhelm the ecosystem. But there's also an alternative view: suppose these hippos are actually helping the ecosystem because they behave like some of the large ancient creatures that used to roam this part of Colombia? That’s what Erick Lundgren–ecologist at the University of Technology in Sydney, Australia–thinks. (Originally aired Apr 2, 2020). (AP Photo/Ivan Valencia)