JACKSON, Wyo. — Have you heard the bugles?

It sure is that time of year. Bull elk are looking to attract mates during the seasonal rut.

From September through mid-October bull elk in the Greater Yellowstone Ecosystem can be heard bugling at twilight. This sound is made to advertise their fitness to cow elk and to show off to other bulls. Listen below.

Video: Nick Sulzer // Buckrail

Elk are most active before sunrise and after sunset but will bugle throughout the night as well. The rut can begin as early as late August and can continue into early November, according to the National Park Service.