On this week's episode: big bird intelligence, astronauts should jump, sheep and human history, and a tiny great ape.

Most of the world’s more than 2 billion sheep and goats are grazed on range in countries such as Australia and New Zealand. Farmers in the United States raised nearly 5.02 million sheep and 2.51 ...

Sheep and cattle grazed relentlessly on the otherwise uninhabited islands for nearly a century before a British bird lover acquired them in 1970. He turned the islands into a private sanctuary ...