Greater Sage-Grouse
The greater sage-grouse is the largest grouse species in North America.
About This Species
There are two species of sage-grouse in Colorado: the greater sage-grouse and the Gunnison sage-grouse. The greater sage-grouse is found in the northwestern part of Colorado.
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Conservation
State Special Concern Species
Historical population declines and ongoing threats to their habitat and populations place greater sage-grouse in Tier 1 of our species of greatest conservation need, but collaborative conservation, management, and monitoring efforts across states has prevented the species from being listed under the Endangered Species Act. Colorado Parks and Wildlife and its partners are involved in efforts to maintain and restore sagebrush ecosystems that greater sage-grouse need for populations to persist.
Conservation
Conserving Greater Sage-Grouse in Colorado
For over 25 years, Colorado Parks and Wildlife has been working to manage and protect the greater sage-grouse. Conservation easements on private lands protect the landscape from development while habitat treatments restore and protect the sagebrush ecosystem. We’ve cleared thousands of acres of encroaching pinyon-juniper forests to restore this imperiled habitat. Researchers are using GPS satellite transmitters to see if grouse are now using the restored areas. We also work to rebuild the natural flow of water to enhance Colorado’s wet meadows for grouse young.
Monitoring Leks
We count males attending leks each spring. Leks are open areas within sagebrush where males congregate and display for females as part of their breeding courtship. There are over 500 known leks in northwestern Colorado, so annual population monitoring requires intensive survey efforts by biologists from several different agencies and organizations. While Greater Sage-Grouse populations fluctuate over time, statewide counts in 2016 were the highest ever recorded.
Research Collaboration
We are not only focused on greater sage-grouse within Colorado but we also collaborate on rangewide studies.
Local Working Groups
Local working groups have been established for five of the six greater sage-grouse populations, and these groups help to coordinate conservation planning on a local scale and keep the public informed.
Research
Researching Greater Sage-Grouse
The largest grouse in North America, the greater sage-grouse is a species of state concern due to range-wide population and habitat declines. CPW is participating in a collaborative conservation effort designed to support greater sage-grouse populations and protect greater sage-grouse habitat. The Avian Research team is conducting a variety of studies to identify and evaluate different management and monitoring strategies.
Intensive and extensive energy development within sagebrush communities in the western United States has raised specific concerns about the species conservation because of evidence linking demographic impacts to Greater Sage-Grouse from active natural gas development. Tri–State Energy and Colowyo Coal Company is funding and working collaboratively with Colorado Parks and Wildlife on a research study located in Moffat County, Colorado. Ultimately, our research will evaluate the efficacy of Greater Sage-Grouse mitigation (avoidance and minimization) efforts and provide some of the first information assessing the response of male Greater Sage-grouse to coal surface mining and mitigation efforts.
Greater sage-grouse is a species of conservation concern due to range-wide population and habitat declines. In Colorado, about 20 percent of the statewide population resides in North Park, but assessments of seasonal distribution and habitat using contemporary data from this important area are lacking. In addition, oil and gas energy development is expected to increase in North Park, and this activity could influence Greater Sage-Grouse distribution. As a result, Colorado Parks and Wildlife initiated a study to obtain current data on seasonal movements in North Park. Using data from 117 radio-marked Greater Sage-grouse, researchers collected almost 4,000 location data points in North Park over two years. Locations were recorded during breeding, summer and winter seasons. Using Geographical Information System, researchers overlaid this location data on vegetation, plant productivity, elevation, and water distribution data layers, as well as location data for oil and gas wells and roads in North Park. These seasonal models provide wildlife managers, landowners, and the energy industry with information they need to identify and address Greater Sage-grouse habitat conservation issues in North Park.
Rapidly expanding energy development over the past decade has raised concerns about the impact of habitat loss in the Parachute-Piceance-Roan population of greater sage-grouse in Northwestern Colorado. The population is also thought to have lost habitat over the past century due to upslope encroachment of pinyon-juniper onto sagebrush-dominated ridges and plateaus.
However, removing encroaching pinyon-juniper may allow us to expand suitable habitat and thereby offset anticipated impacts of energy development. Pinyon-juniper removal projects have been widely implemented across the western U.S. to increase suitable habitat for sage-grouse, but how sage-grouse respond to removals is poorly studied.
In 2008, Colorado Parks and Wildlife partnered with industry, the Bureau of Land Management, and private landowners on a multi-year research project to experimentally test how quickly and successfully greater sage-grouse habitat could be restored by removing sparse pinyon-juniper trees from areas otherwise dominated by sagebrush. Annual surveys for sage-grouse pellets began on nine study plots in 2008 and expanded to 23 study plots in 2010. All study plots were on ridges dominated by sagebrush. Of those, about one-third were reference plots that lacked pinyon-juniper encroachment, one-third (976 acres total) were treated plots where pinyon-juniper was removed part-way through the study, and the remaining third were untreated plots where pinyon-juniper was left standing for the duration of the study. Pellet surveys were conducted in summer from 2008-2015. An increase in sage-grouse pellet counts within 4-5 years of pinyon-juniper removal was documented on only 2 of 8 treated plots.
Lek counts are the primary index used by state wildlife agencies to monitor changes in greater sage-grouse abundance, but current lek-count monitoring relies on untested assumptions about lek attendance, detectability, inter-lek movement, sex ratio, and the proportion of leks that are known and counted. Given the availability of new methodological and statistical approaches to estimate wildlife populations, it is worth comparing the performance of current lek-count approaches versus other estimation methods.
Dual-frame sampling of leks and non-invasive genetic mark-recapture analyses based on winter pellet sampling are promising alternatives for monitoring trends in sage-grouse populations. The purpose of this study is to evaluate and compare the reliability and efficiency of dual-frame lek sampling with helicopters, non-invasive genetic mark-recapture sampling, and standard lek counts for estimating population size and trend and to estimate sex ratio in the Parachute-Piceance-Roan population in Northwest Colorado.
Field data collection was conducted from fall 2011 to spring 2014. For dual-frame sampling, we are using occupancy modeling to account for imperfect detectability of leks in each sampling frame. We are analyzing pellet samples collected in winter 2012-2013 and winter 2013-2014 to derive genetic data for mark-recapture and spatial mark-recapture analyses to allow us to estimate sex-specific abundance for the population in each year.
Implementing effective monitoring and mitigation strategies is crucial for conserving populations of greater sage-grouse in Colorado. Lek counts are widely used as an index of abundance to monitor trends in sage-grouse populations. However, because lek counts rely on untested assumptions, how closely lek-count data track actual changes in male abundance from year to year remains unknown. Lek locations are also commonly used to help identify and protect important sage-grouse seasonal habitats. However, the effectiveness of lek buffers for reducing disturbance to breeding male sage-grouse and the habitats they use have not been widely tested.
We deployed solar-powered, satellite-based, global-positioning-system transmitters on male greater sage-grouse and conducted double-observer counts at leks to obtain data on male survival, lek attendance, inter-lek movements, detectability, and diurnal and nocturnal space use around leks during the breeding season in the Parachute-Piceance-Roan population in NW Colorado in spring from 2012-2015. These data will allow us to evaluate assumptions underlying the use of lek-count data and ultimately, to test their reliability for providing information about sage-grouse population trends. Data on space use will also allow us to evaluate whether lek buffers are effective for conserving greater sage-grouse habitat in oil and gas fields.
Implementing effective monitoring and mitigation strategies is crucial for conserving populations of greater sage-grouse in Colorado. Lek counts are widely used as an index of abundance to monitor trends in sage-grouse populations. However, because lek counts rely on untested assumptions, how closely lek-count data track actual changes in male abundance from year to year remains unknown. Lek locations are also commonly used as surrogates to help identify and protect important sage-grouse seasonal habitats. However, the effectiveness of lek buffers for reducing disturbance to breeding male sage-grouse and the habitats they use have not been widely tested.
We deployed solar-powered, satellite-based, global-positioning-system transmitters on male greater sage-grouse and conducted double-observer counts at leks to obtain data on male survival, lek attendance, inter-lek movements, detectability, and diurnal and nocturnal space use around leks during the breeding season in and around the proposed Hiawatha Regional Energy Development project area in northwest Colorado and southwest Wyoming in spring from 2011-2014. These data will allow us to evaluate assumptions underlying the use of lek-count data and ultimately, to test their reliability for providing information about sage-grouse population trends. Data on space use will also allow us to evaluate whether lek buffers are effective for conserving greater sage-grouse habitat in oil and gas fields.
Growing concern for conservation of greater sage-grouse has led to widespread efforts to better understand their demographic rates, movement, habitat selection, and responses to disturbance. The majority of research projects use very high frequency (VHF) transmitters attached to a necklace collar to radio-track individual sage-grouse.
However, recent technological advances have led to commercial production of 22-30 g, solar-powered, global positioning system platform transmitter terminal transmitters suitable for use with greater sage-grouse. GPS transmitters allow collection of multiple locations per day at pre-programmed times, access on the ground is not required to obtain locations, data are gathered without disturbing marked birds or their flockmates, and they provide high-resolution data on survival, movements, habitat use, and nesting.
We conducted a 1-year pilot study to compare survival and nest initiation between female greater sage-grouse with traditional very high frequency neck collars versus those with rump-mounted solar GPS PTT transmitters in the Hiawatha Regional Energy Development Project area in Northwest Colorado and Southwest Wyoming. Preliminary results suggest that survival of GPS females was lower than that of very high frequency females and that several improvements to transmitter and harness design and attachment method were needed to reduce impacts of GPS transmitters on female greater sage-grouse. Additional study will be needed to rigorously test the effects of GPS transmitters on greater sage-grouse once such improvements are incorporated.
Recent energy development within sagebrush habitat has led to concern for conservation of greater sage-grouse populations, and both industry and regulatory agencies need better information on when and where sage-grouse occur to reduce impacts from development. Previous studies have shown that intensive energy development can lead to avoidance, lower abundance, and reduced lek persistence.
Sage-grouse often move long distances to find suitable winter habitat and typically have high seasonal site fidelity (i.e., returning to winter in the same areas year after year). For that reason, energy development within wintering areas may have disproportionately large effects on local or regional populations. Resource selection functions can now be combined with geographic information system layers to model habitat use by sage-grouse and to map key seasonal habitats at high resolution at a landscape scale. Although we know that local habitat features like shrub species, height, and cover are important in determining winter habitat quality for sage-grouse, individuals likely also select habitat based on the extent of suitable vegetation and topography around them at larger scales, so managers also need to understand sage-grouse landscape-scale habitat requirements.
Multi-scale habitat use models, landscape-scale habitat guidelines, and high-resolution seasonal habitat-use maps will streamline planning and mitigation for industry and facilitate sage-grouse conservation in areas with energy development. The proposed Hiawatha Regional Energy Development Project overlaps approximately 70% of the known winter habitat and a portion of the documented nesting and brood-rearing habitat for the sage-grouse population that breeds in the tri-state border region in Northwest Colorado, Southwest Wyoming, and Northeast Utah. For that reason, there is concern that the Regional Energy Development Project may lead to declines in local populations to levels below population targets established by Colorado Parks and Wildlife and the Northwest Local Working Group.
We conducted a cooperative, 3-year research project within the proposed Hiawatha Regional Energy Development Project boundary in Northwest Colorado and Southwest Wyoming to (1) produce high-resolution conservation planning maps that delineate important seasonal sage-grouse habitats, (2) evaluate the relative importance of landscape-scale vs. local-scale habitat characteristics in winter habitat selection, (3) identify winter landscape-scale habitat guidelines, and (4) assess whether historical energy development affects current habitat selection.
- Resource selection by greater sage-grouse varies by season and infrastructure type in a Colorado oil and gas field
- Seasonal Habitat Mapping for Greater Sage-grouse in the Parachute-Piceance-Roan Population in Northwestern Colorado
- Developing Distribution Models for Managing Greater Sage-grouse in North Park
- Genetic mark-recapture analysis reveals large annual variation in pre-breeding sex ratio of greater sage-grouse
- Genetic mark-recapture analysis of winter fecal pellets to estimate population size in greater sage-grouse
- Dual-frame lek surveys for estimating sage-grouse populations
- Quantifying habitat loss and modification from energy infrastructure in the Parachute-Piceance-Roan greater sage-grouse population
- Atypical primary molt patterns in greater sage-grouse: implications for age classification
- An improved rump-mount harness design for greater sage-grouse
- Coupling tracking technologies to maximize efficiency in sage-grouse research
Managing and Conserving Greater Sage-Grouse
Colorado Greater sage-grouse Plan
Find out moreConservation Management Plan - Northwest Colorado
Find out moreConservation Management Plan - Eagle and South Routt
Find out moreConservation Management Plan - Middle Park
Find out moreConservation Management Plan - North Park
Find out moreConservation Management Plan - Parachute-Piceance-Roan (PPR)
Find out moreMore Information:
Physical Characteristics
On the ground and in flight they appear brown speckled with black, white, and gold, and their long pointed tail is approximately half the length of their body. Both sexes have narrow, pointed tail feathers, feathering to the base of the toes, and a variegated pattern of grayish brown, buff and black on the upper parts, with paler flanks and a diffuse black pattern on the abdomen. Males often weigh in excess of 4-5 pounds and hens weigh in at 2-3 pounds.
Males
Adult males have blackish-brown throat feathers which are separated by a narrow band of white from a dark V-shaped pattern on the neck. White breast feathers conceal 2 large, skin sacs (used in courtship displays) which are yellow-green in color. Males also have yellow eyecombs (obvious in the spring during courtship displays). They also have black filoplumes (fine hair-like feathers) from their lower crown along the nape of their neck which are visible during a male's courtship display.
Females
Female sage-grouse lack the specialized features that males have for courtship displays but generally resemble males in coloration. However, in comparison to males, their throats are buffy with blackish markings and the lower throat and breast are barred which presents a blackish-brown appearance.
Young
Juveniles and yearlings birds (3-15 months of age) can be distinguished from older adults by the presence of 1-3 retained, juvenile outer primary feathers on the wing.
Range
The greater sage-grouse can be found in sagebrush-dominated landscapes in 11 western states and 2 Canadian provinces. Colorado represents the southeastern edge of its overall range in North America. In Colorado, greater sage-grouse are found in the northwestern part of the state, with seven delineated populations (Northwest Colorado, North Park, Middle Park, Northern Eagle-Southern Routt, Parachute-Piceance-Roan, Meeker/White River, and Laramie River).
Habitat
Greater Sage-Grouse, as their name implies, are typically found in landscapes where sagebrush is abundant. Sagebrush is a critical component of their habitat, providing food and cover year-round. Although these birds are typically found at elevations from 6000-9000 feet, they are not forest grouse, instead preferring open, sagebrush-covered flats, slopes, ridges, and plateaus. During late fall, winter, and spring, birds are found almost exclusively in sagebrush. In summer through early fall, birds sometimes also use areas where sagebrush co-occurs with other habitat types (e.g., grassland/pasture, greasewood, aspen, forest, pinyon-juniper, and agricultural fields).
Diet
Sage-grouse primarily eat sagebrush leaves and buds, flowers, insects, and a variety of forbs (broad-leaved herbaceous plants). Chicks depend on forbs and insects for food through early fall. As winter approaches, and other food sources become unavailable, sage-grouse become increasingly dependent on sagebrush. In winter, sagebrush makes up >99% of their diet. In addition, sagebrush provides important escape cover and protection from the elements. Greater sage-grouse sometimes also roost in snow burrows in winter.
Reproduction
IIn late winter (early March), males start to congregate on traditional strutting grounds or leks. Females start to arrive at leks 1-2 weeks later. Leks can occur in a variety of locations (windswept ridges, knolls, flat bare openings in the sagebrush, open fields near sagebrush). Breeding occurs on the leks and in adjacent sagebrush, typically from late March through May. Males strut in a complex, ritualistic breeding display involving swishes, pops, and growls. Females breed with males, then nest in the surrounding sagebrush, laying a clutch of 7-9 eggs. Unless eggs are eaten by a predator, chicks hatch after an incubation period of 25-29 days. Most nests hatch in May and June, but older females whose first nests are depredated often nest again. In early summer, hens move their broods to relatively moist areas (either higher-elevation sagebrush-grasslands, shallow sagebrush drainages, the bottoms of sagebrush-greasewood draws, or irrigated hay meadows) in close proximity to sagebrush. Broods start to break up when chicks are 10-12 weeks of age. In fall, young birds undergo an incomplete molt, retaining 1-3 juvenile outer primary feathers, whereas adults typically undergo a complete molt. Breeding-aged males start molting after the breeding season is over, whereas females start molting once they finish nesting. Breeding-aged males tend to remain segregated from females and broods in summer and fall, but greater sage-grouse often form large, mixed-sex flocks, sometimes with hundreds of birds, in winter.
Threats to Species
- Energy Development and Land Use
- Residential and Commercial Development
- Sagebrush Removal/Agricultural Conversion
- Invasive Weeds
- Pinyon-Juniper Encroachment
- Transportation Corridors
- Emerging Infectious Disease