The Gunnison grouse, Gunnison sage-grouse or lesser sage-grouse is a species of grouse endemic to the United States. It is similar to the closely related greater sage-grouse in appearance, but about a third smaller in size, with much thicker plumes behind the head; it also has a less elaborate courtship dance. The Gunnison Grouse is an endangered species. Off the lek, males make a soft wut call when warning others of predators. Females give a variety of calls, though their function has not been well studied. When accompanying a brood, females have both a contact call, and a call to warn their young of danger. To distract or confront a predator, they use a loud hissing call. Females also call when soliciting males on the lek. The outlandish male strutting display is a complex, finely timed sequence of sounds, both vocal and mechanical. It begins with three wing shushes, separated by about one second, that are achieved by the male heaving his vocal sacs, enclosed in a neck pouch, through his wings that are held rigidly at his side. The shush sound is produced when the rough feathers on the neck pouch are dragged through his wings, and is only heard when the bird is very close by. In between the wing shushs are a set of low coos and pops that collectively sound like a bubbling. After the three shushes, the male expels air from his esophageal sac, making a burp-like sound, and shimmies his tail. Here is a link to their calls and here is a link to their outlandish display.