Humans are to blame for the drastic declines in river dolphin populations around the world, writes Rachel Nuwer. But what exactly are we doing wrong? Mainly, scientists have found, it's building dams - and so destroying and fragmenting their habitat.
If rhinos are driven to extinction in the wild, Africa's landscapes and ecosystems would be very different, reports Rachel Nuwer. The activities of this mega-herbivore diversify plant life and create prime grazing spots for other animals.
It's not just people, animals and trees that suffer from radiation at Chernobyl, writes Rachel Nuwer, but also decomposer fungi and microbes. And with the buildup of dead wood comes the risk of catastrophic fire - which could spread radiation far and wide.
