The New York Department of Environmental Conservation is revising its plan to control the state’s 2,200-strong mute swan population by killing (and oiling the eggs of) the invasive species. The agency has received 16,000 letters and 30,000 signatures protesting its mass death sentence, which was announced in January, because people do not like the idea of executing beautiful white birds, even if they are harmful to other creatures (or airplanes). The new, probably non-lethal plan will be released in the spring.