rut

The annual mating season of deer, elk, and other cervids — a period of intense competition in which males bugle, clash antlers, and fight for access to females. The rut transforms the behavior of normally wary, solitary animals: bulls become reckless, aggressive, and noisy. A rutting elk's bugle carries for miles. Also: a deep track worn into soft ground by repeated passage of wheels or hooves — a groove that captures and directs subsequent traffic. Both senses share a root in the idea of a course once entered that is difficult to leave.