The Case of the Vanishing Grouse
I recently had the privilege of guiding several keen birders who were visiting Colorado in pursuit of it wild grouse. The month of April brings many bird enthusiasts to the Centennial State in search of its seven grouse species, five of which engage in flamboyant courtship displays throughout the month of April. The Greater Prairie Chicken (Tympanuchus cupido), Lesser Prairie Chicken (Tympanuchus pallidicinctus), Sharp-tailed Grouse (Tympanuchus phasianellus), Greater Sage-Grouse (Centrocercus urophasianus), and Gunnison Sage Grouse (Centrocercus minimus) all perform on regularly-used leks, some of which can be visited by birders and photographers. The Dusky Grouse (Dendragapus obscurus) and White-tailed Ptarmigan (Lagopus leucura) do not perform on leks and can be more difficult and less reliable to find.
My favorite grouse found here in Colorado is the Greater Sage-Grouse. Its rapidly dwindling habitat and contrasting stakeholder opinions around grouse conservation have led to it becoming known as the most controversial bird in the west. Last week, I took a client to observe a lek near Walden, Colorado. Our discussions took us in many directions, but some of the topics we touched on our outlined below.
A male Greater Sage-Grouse displays on a lek near Walden, Colorado
The Greater Sage-Grouse
The Greater Sage-Grouse (C. urophasianus) or Sagehen is a large, upland gamebird of the high plains and sagebrush flats of the American West. Each spring, it returns to ancestral lekking grounds where males put on a bizarre “strutting display”, gulping up to a gallon of air to inflate two bulbous yellow air sacs, puffing out their chests and fanning their tails to woo females. Although dozens of birds can display on one lek, it is usually only one or two males who get selected by the females to mate. This puts intense pressure on each male to perform his absolute best so he can be the lucky one to pass his genes onto the next generation.
Watching this spectacle unfold is truly magical. In the pre-dawn hour, we sit and listen to the enchanting booming of the grouse – that liquid bubbling sound of air being squeezed out of the air sacs with force. As the sun rises above the distance mountains, the glow of light reveals the strange, alien-like males, replete with wiry philoplume ponytails and full-bannered tails. Several cryptic hens line up to watch the show as the males face off against one another, doing their best to impress them.
These extremely specialized birds are severely threatened by habitat loss, degradation, invasive species, and climate change. The Sage-Grouse evolved with sagebrush and depend on it for about 70% of their year-round diet. These birds do not have a muscular gizzard to grind up seeds and other hard food items, so they are limited to eating only fleshy leaves and a few soft-bodied insects. Ranching and agriculture have destroyed much of the historic sagebrush habitat across its range. In many areas where sagebrush still thrives, invasive cheatgrass (Bromus tectorum) has taken hold, causing more frequent and destructive wildfire events. In addition, residential building and energy development has also had an impact on the Greater Sage-Grouse population.
About 100 years ago, Greater Sage-Grouse populations numbered around 16 million birds. Today, they number somewhere between 200,000 and 500,000 birds. Since 1965, they have experienced an 80% range-wide population decline and populations have dropped by 43% just in the last two decades. A multi-agency study published in 2022 found that 1.3 million acres of sagebrush habitat are vanishing each year! At that rate, the remaining healthy habitat will be gone around mid-century.
Source: Andy McGlashen/Audubon Magazine, Spring 2023
Since over a half of all remaining sagebrush occurs on private land, the USDA’s Natural Resources Conservation Service has used Farm Bill funds to work with private landowners through the Sage-Grouse Initiative to provide incentive-based partnerships to help protect Sage-Grouse habitat. Although at one time a candidate for endangered species listing, the U.S. government has still declined to list the Sage-Grouse, as it would directly impede energy development projects across the western U.S.
Observing Sage-Grouse on a Lek
Witnessing the courtship display of the Greater Sage-Grouse is truly memorable, but please do so with ethical precaution and respect. They are sensitive to disruption and will abandon a lek if overly disturbed. If you want to visit a known lek, please adhere to the following protocol:
Arrive at least one hour before sunrise
Do not drive on or near the lek and park away from the edge of the lek
Turn off your engine and lights and stay in the vehicle
Do not leave the lek until the birds do
Late April is the best time to observe leks because most of the mating has already taken place and the males are still strutting their stuff
What We Can Do to Help
We can help Sage-Grouse and other sensitive species by supporting organizations who work with ranchers to improve range health and who protect land through purchases and easements to set aside critical habitat. This year, Birding Man Adventures has donated 5% of our Sage-Grouse tour revenue to the Nature Conservancy. Let’s all do what we can to protect our unique natural heritage.