2,000 of them living in and around the city of chicago by some estimates. every major u.s. city has them, l.a. to boston to the biggest concrete jungle of all, new york city. i think it s safe to say that there are literally millions of people living within a few yards or a few hundred yards of coyotes on a pretty regular basis. reporter: wildlife ecologist stanley garrett tracks the ghost-like creatures. she s right down there. reporter: he spent the last decade tracking and collaring 500 urban coyotes in chicago. there may be more. reporter: in all his years, in all his encounters, they ve been docile, a little more than a nuisance, at least he thought so. until he investigated what happened to taylor mitchell, a 19-year-old folk singer and a rising star in canada. lost my mother reporter: this young woman single-handedly turned everything scientists know about coyotes upside down. she s the first and only adult human on record to have been killed by a coyote.