Aldo Leopold, ecologist and author of Sand County Almanac took such detailed notes each morning from his back porch that researchers at University of Wisconsin-Madison have created his “resurrected soundscape” with digital bird calls.

“Leopold recognized that you can get a pretty good sense of land health by listening to the soundscape,” [wildlife ecology profesor Stan] Temple told UW News. “If sounds are missing and things are there that shouldn’t be, it often indicates underlying ecological problems.”