PRI's The World Published by PRI's The World London's pigeon problem has a simple solution: a hawk Listen Queue Download this audio Want to embed this player? Use the code below. More info. <iframe frameborder="0" scrolling="no" height="130" width="100%" src="https://www.wnyc.org/widgets/ondemand_player/wnyc/#file=/audio/json/742896/&share=1"></iframe> Share on Facebook Share on Twitter Email a Friend Fifteen years ago, the center of London was densely populated, not just with people, but with pigeons. But something has changed. One of the reasons can be found every morning in Trafalgar Square.