Nature and EnvironmentIndiaTeaching conservation: Delhi's 'nest man'02:33This browser does not support the video element.Nature and EnvironmentIndia05/18/2022May 18, 2022When he moved to India's capital, Rakesh Khatri noticed something was wrong: He didn't hear any birds chirping. So, to bring back his favorite sounds, Rakesh Khatri took up a hobby that has since become his life's work.Copy linkAdvertisement