Let’s keep the fun of National Wildlife Refuge Week going with this awesome elk at Charles M. Russell National Wildlife Refuge in Montana. During the fall rut, bull elk bellow out a series of grunts and whistles called a bugle. It’s a call to combat. In the mating season, challengers bugle to dominant elks, announcing a duel for the right to mate. This is just one of the many terrific sight and sounds you’ll find when you explore the outdoors. Photo by Somesh Nagthan (www.sharetheexperience.org).