Dave Davies

In his new book, Doug Saunders says there are those who believe immigration and high birth rates will make Muslims a majority in Europe in coming decades -- and their hostility to Western values makes them a threat. Saunders tells Fresh Air that such fears are based on inaccurate assertions of fact.

ProPublica investigative reporter Peter Maass says that cellphone companies monitor where we are, who we call, what we buy -- and often provide it to law enforcement when requested. "They are collecting a heck of a lot more information than we expect them to be collecting about us," he tells Fresh Air.

Thor Hanson's new book looks at the evolutionary significance of feathers in birds. Hanson tells Fresh Air that he's amazed by birds' magnitude of feathers, how feathers grow and how they're the "most efficient insulation known."