Wolves are a rare species in western Europe, but in eastern Europe they are more common. At one time, wolves roamed the entire continent. They began to disappear when human settlers cleared the forests for agriculture. Should wolves now be brought back?
The northern white rhinoceros is almost gone. Seven of them remain: four in Kenya, two in the United States, one in the Czech Republic. More than ten years have passed since the last of them reproduced. Fortunately, there's more than one way to make a rhino.