Sage grouse struts his stuff

Greater sage grouse males strut their stuff for the cameras of Gail Patricelli‘s lab (and the female grouse) on a mating lek in Wyoming, in 2008.

In the spring, greater sage grouse males (Centrocercus urophasianus) gather together on open knolls and patches of bare soil and low vegetation in groups called leks. Like gyms or bars, lekking grounds are social performance spaces, where males spread their tail-feathers, inflate their impressive chests, and strut about, calling amorously to the lady birds. To entice female sage grouse to choose them as mates, the males shake the fluffy white rolls around their necks and puff out the two naked, yellow air sacs in the gular skin under their chins, “burping” air out of the sacs in loud exhales.

Just a few hot males will successfully woo most of the females visiting the lek. Ecologist Gail Patricelli of UC Davis captured the above video of a lek near Hudson, Wyoming. She and her students and postdocs observe animal communication in the wild with a specially developed array of microphones and digital cameras that captures the directionality of birdsong as well as bird behavior and the ecological context of their mating displays.

Previous studies have suggested that loudness influences the females’ choice. The direction of the male’s vocal projection affects the female’s perceptions of loudness, so Patricelli and postdoc Alan Krakauer have set out to test the idea with their recording system and a robotic female grouse puppet fitted with a microphone and video camera.

A sea of non-native crested wheatgrass, poor habitat for sage grouse, fills the path of the Poison Creek fire (left), which burned on Idaho’s remote Owyhee High Plateau, in 1996. Nearly two decades later, an abrupt transition to healthy sagebrush marks the edge of the fire. Read more about this in the accompanying Ecotone article. Credit, Robert Arkle, June 2011.

Patricelli’s lab is also investigating the possibility that noise from the booming energy sector, namely natural gas and coal bed methane production, has contributed to the decline of sage grouse numbers in Wyoming. Development, wildfire, habitat fragmentation, and ecosystem changes wrought by non-native species all pressure sage grouse, which mate, forage, and nest on the ground. US Fish and Wildlife Service named the grouse’s habitat, the Great Plains sage-steppe, one of the most imperiled ecosystems in America.

More about sage grouse:

Sage grouse losing habitat to fire as endangered species decision looms. Ecotone 3 April 2014.

See more sage grouse action: photographer Ronan Donovan has nice HD footage of a Montana Lek on Vimeo.

KE Doherty, JD Tack, JS Evans, and DE Naugle. (2010) Breeding densities of greater sage-grouse: A tool for range-wide conservation planning. Bureau of Land Management. Caption from the BLM website: Range-wide sage-grouse breeding density areas represent spatial locations of 25%, 50%, 75%, and 100% of the known breeding population, differentiated by color. Red areas contain 25% of the nesting population in 3.9% of the bird’s occupied range. Because colors are additive, red and orange areas combined capture 50% of the population in 10% of the range. Collectively, breeding density areas contain 25% of sage-grouse in 3.9% of the species range (2.9 million ha), 50% of birds in 10.0% of range (7.5 million ha), 75% of birds in 26.9% of range (20.4 million ha), and 100% of the known population in 54.6% (41.2 million ha) the species range.