In this episode, Leiden University bird song expert Hans Slabbekorrn notes the changes in bird vocalizations when they move from the forest to the city. And we wrap up our series on Scientific American magazine's "SA 50" citations with Ivo Menzinger, managing director of sustainability and emerging risk management for the reinsurance company Swiss Re. Plus we'll test your knowledge of some recent science in the news. Websites mentioned on this episode include www.sciam.com/podcast; www.sciam.com/news