When biologist Danielle Whittaker started studying bird odors, some scientists tried to discourage her, claiming that birds can’t smell. But that only deepened her curiosity. Once, she caught a whiff of a cowbird, which smelled to her like sugar cookies. Danielle and her colleagues studied Dark-eyed Juncos and found that they produce many odors that help influence breeding behavior. Learn more in Danielle Whittaker’s new book, The Secret Perfume of Birds: Uncovering the Science of Avian Scent.