A. Seasonal Habitat Use, Movements and Vital Rates in the Parachute-Piceance-Roan Population of Greater Sage-Grouse
Colorado Parks and Wildlife (CPW) is continuing a study of the Parachute-Piceance-Roan (PPR) population of greater sage-grouse (
Centrocercus urophasianus), starting in 2007. A pilot study was conducted in 2006.
The PPR is one of several small, spatially fragmented populations of sage-grouse in Colorado. Sage-grouse habitat is highly fragmented in the PPR, and this area is also undergoing rapid oil and gas development.
This project is the result of a working relationship between CPW, industry, other land owners and managers in the PPR area to monitor the PPR grouse population and plan for future management actions. The objectives of the study are to obtain current, baseline information on the genetic characteristics of these grouse; measures of reproduction and survival rates; and determine patterns of habitat use and seasonal movements by PPR sage-grouse. This information will be useful in assessing the current population status and expected future trend of PPR sage-grouse, and for identifying alternative management strategies for this population.
B. Seasonal Habitat Mapping for Greater Sage-grouse in the Parachute-Piceance-Roan Region of Western Colorado
Current research on greater sage-grouse (Centrocercus urophasianus) in the Parachute-Piceance-Roan (PPR) region of western Colorado is being conducted by Dr. Brett L. Walker and is an extension of previous work conducted by Dr. Anthony D. Apa and Dr. Jeffrey L. Beck. In 2006, CPW and industry partners initiated a 3-year study to obtain baseline data on seasonal habitat use, movements, vital rates, and genetics of greater sage-grouse in the PPR (see above). Since then, CPW has identified the need for high-resolution, population-specific maps showing concentrated seasonal-use areas. These efforts are the result of a working relationship between CPW, industry, private landowners, BLM, and managers in the PPR region to help conserve the PPR grouse population as energy development proceeds.
Large-scale changes to sagebrush habitats throughout western North America have led to growing concern for conservation of greater sage-grouse and repeated petitions to list the species under the Endangered Species Act. The PPR is the southernmost population of greater sage-grouse in Colorado, where habitat is naturally fragmented and limited by topography. Sage-grouse in PPR are experiencing rapidly increasing energy development.
Generating high-resolution maps for where sage-grouse occur in each season allows us to identify important seasonal habitats for the entire population at a scale matching that of potential stressors. Such analyses also allow us to test the geographic scale at which habitat features influence sage-grouse habitat use. Mapping will also benefit regulatory agencies and industry because critical habitats can be identified during the planning stage before development occurs, mapping reduces the need for costly on-site surveys, best management practices and reclamation can be tailored according to seasonal habitat use, and restrictions on development can be relaxed in non-critical habitats. Avoidance of critical habitat in turn reduces the need for expensive, long-term mitigation. Mapping seasonal habitats is a high-priority conservation strategy in the Colorado Statewide Greater Sage-Grouse Conservation Plan and will assist in applying targeted management and mitigation actions within sage-grouse habitat.
Objectives of this study are to:
- Investigate the scale at which habitat features influence habitat selection by sage-grouse.
- Create high-resolution maps showing important greater sage-grouse seasonal habitat-use areas in the PPR for use by state and federal agencies, industry, and private landowners.
C. Assessment of Pinyon-Juniper Removal as Mitigation for Greater Sage-grouse in the Parachute-Piceance-Roan Region of Western Colorado
Colorado Parks and Wildlife is assessing the value of removing encroaching pinyon-juniper from sagebrush to restore habitat as mitigation for potential losses due to energy development.
Large-scale changes to sagebrush habitats throughout western North America have led to growing concern for conservation of greater sage-grouse and repeated petitions to list the species under the Endangered Species Act. The PPR is the southernmost population of greater sage-grouse in Colorado, where habitat is naturally fragmented and limited by topography. Sage-grouse in PPR have experienced a long-term decline in habitat suitability and range contraction associated with pinyon-juniper (PJ) encroachment.
Pinyon-juniper encroachment into sagebrush in the PPR has occurred over the last 150 years and is thought to be caused by fire suppression, reduced fire frequency due to grazing, and windows of climatic conditions suitable for PJ establishment during the late 1800’s and 1940s. The presence of relatively young trees in sagebrush habitat also suggests a more recent period of establishment. Pinyon-juniper expansion has been identified as a problem for sage-grouse populations throughout Colorado. This expansion has reduced available suitable habitat for sage-grouse in the PPR region, particularly at lower elevations. Pinyon-juniper removal projects have been widely implemented to increase suitable habitat for sage-grouse, but how sage-grouse respond to removals is poorly studied and key questions remain unanswered: (1) how long does it take for sage-grouse to colonize areas where PJ encroachment is controlled, (2) what level of PJ encroachment inhibits sage-grouse use of otherwise suitable sagebrush habitats. Current research efforts in the PPR hope to quantify how PJ removal influences frequency of winter and summer habitat use by sage-grouse. Specifically, our research will quantify the relationship between sage-grouse winter occupancy, the number of individuals present estimated from genetic samples, pellet occupancy, and PJ density at various scales around occupied sites and quantify how long it takes for sage-grouse to begin using treated areas. This phase of research focuses on assessing short-term (2-5 years) responses of sage-grouse to PJ removal.
Objectives of this study are to:
- Quantify the relationship between PJ density and sage-grouse winter and summer habitat use.
- Assess the magnitude and timing of sage-grouse response to removal of encroaching PJ.
- Test the influence of landscape-scale habitat features in determining success of PJ removals.
- Test winter track surveys as a new method for assessing changes in frequency of use by sage-grouse.
D. Evaluating Lek-Based Monitoring and Management Strategies for Greater Sage-Grouse in the Parachute-Piceance-Roan Population in Northwestern Colorado
Implementing effective monitoring and mitigation strategies is crucial for conserving populations of sensitive wildlife species. Concern over the status of greater sage-grouse populations has increased both range-wide and in Colorado due to historical population declines, range contraction, continued loss and degradation of sagebrush habitat, and potential federal listing of the species under the Endangered Species Act. Despite untested assumptions, lek-count data continue to be widely used as an index of abundance by state and federal agencies throughout the species' range to monitor sage-grouse populations. Lek locations are also commonly used as a surrogate to identify and protect important sage-grouse breeding and year-round habitat. However, the use of lek counts and lek locations to monitor and manage sage-grouse populations is controversial because it is unknown how closely lek-count data track actual changes in male abundance from year to year, or if lek buffers are effective at reducing disturbance to male sage-grouse and their habitat during the breeding season.
Colorado Parks and Wildlife is conducting a four-year study from 2012-2015 deploying solar-powered GPS PTT transmitters on male greater sage-grouse to obtain data on male survival, lek attendance, inter-lek movements, and diurnal and nocturnal habitat use around leks and conducting double-observer lek counts to estimate detectability of males on leks during the breeding season in the Parachute-Piceance-Roan population in northwestern Colorado. These data will allow us to evaluate whether current lek-based monitoring methods provide reliable information about sage-grouse population trends and which types of lek buffers are most effective for protecting breeding males.
Objectives of this study are to:
Use locations of GPS males to find, verify, and count new leks
Estimate the number of known and unknown leks in the population
Estimate age-specific rates of daily, seasonal, and annual male lek attendance
Estimate the frequency, timing, and distance of inter-lek movements by breeding males
Estimate detectability of males attending leks using paired helicopter and ground counts and paired ground counts
Quantify how variation in age-specific male survival, detectability, lek attendance, inter-lek movement, and count effort affect indices and trend estimation using standard lek-count data
Quantify male habitat use around leks to inform use of lek buffers
E. Evaluation of Alternative Population Monitoring Strategies for Greater Sage-Grouse in the Parachute-Piceance-Roan Population of Western Colorado
Principal Investigators:
- Jessica Brauch, PhD student, Colorado State University.
- Advisor: Dr. Barry Noon, Colorado State University.
- Co-advisor, committee member, and CPW representative: Dr. Brett Walker, Colorado Parks and Wildlife
Robust estimates of population size and population trend provide the scientific basis for managers to make appropriate and defensible recommendations regarding land-use decisions, harvest regulations, and mitigation efforts to conserve wildlife. When linked with environmental variables, they also allow managers to examine population responses to disease, land-use patterns, habitat treatments, weather, ecological succession, and disturbance. Significant progress has been made over the past three decades in sampling methodology, statistical analysis, and tracking technology to help estimate wildlife abundance. However, many monitoring programs continue to use uncorrected and untested population indices. Lek counts are the primary index used by all state wildlife agencies in the western U.S., including Colorado Parks and Wildlife, to monitor changes in greater sage-grouse (Centrocercus urophasianus) abundance, but lek counts rely on untested assumptions about male lek attendance, detectability, inter-lek movement, sex ratio, and the proportion of leks in the population that are known and counted. Colorado Parks and Wildlife currently uses maximum counts of males from multiple counts at each lek as the basis for calculating 3-year running averages for each lek and population zone. Given the availability of new methodological and statistical approaches, it is worth comparing use of uncorrected lek counts versus other potential monitoring methods in terms of estimator precision, cost, practicality, and potential for disturbance.
The purpose of this study is to evaluate and compare the reliability and efficiency of dual-frame sampling, non-invasive genetic mark-recapture, and standard lek counts for estimating population size and trends and to estimate sex ratios in the Parachute-Piceance-Roan (PPR) population of greater sage-grouse in western Colorado.
Objectives of this study are to:
- Estimate proportion of known leks, the average number of males attending known leks, and the total number of male greater sage-grouse attending leks in the population during three consecutive lekking seasons using dual-frame sampling of 1-km2 cells from helicopter
- Estimate population size using genetic mark-recapture during two consecutive fall/winter seasons
- Estimate sex ratio using genetic sampling during two consecutive fall/winter seasons
- Compare and contrast methods for estimating population size and evaluate the application of auxiliary data for improving estimations based on standard lek-count data
Dispersal Ecology of Greater Sage-Grouse in Northwestern Colorado: Evidence From Demographic and Genetic Methods
Principal Investigators: Drs. Thomas R. Thompson, Anthony D. Apa, and Kerry P. Reese
By: Dr. Thomas R. Thompson
Major Professor: Dr. Kerry P. Reese
Committee member and CPW Representative: Dr. Anthony D. Apa
This greater sage-grouse project report is the culmination of research conducted from March 2005 through June 2008. The research was in cooperation with the University of Idaho and Dr. Kerry P. Reese, who produced a Ph.D.
Dissertation 
(5MB) from Dr. Thomas R. Thompson. Dr. Thompson’s Dissertation is organized into 6 Chapters which generally have the following conclusions:
- Eggs from wild female GRSG can be collected and hatched, and the chicks can be successfully raised to 10 days of age. (Figure 1a, 1b, and 1c)
- The captive-reared chicks can be successfully augmented and adopted into wild broods and the augmented chicks have similar survival and dispersal patterns of their adopted siblings.(Figure 1d)
- This is the first report of chick survival from hatch to 1 year of age, but varies by study area, gender, and year (see Dissertation (5MB) for details). (Figure 1e, 1f, and 1g)
- GRSG exhibit male-biased dispersal and the results contrast with previous reports of GRSG dispersal conducted 30 years ago with differing techniques. Females can exhibit large movements from natal areas (areas they were hatched), but ultimately exhibit more fidelity to their natal areas than males.
- The gender biased dispersal patterns are similar with genetic and demographic methods.
Dissertation Abstract: The greater sage-grouse (Centrocercus urophasianus; here after sage-grouse) has undergone dramatic population declines over the last 25 years as a result of loss, fragmentation, and degradation of sagebrush (Artemisia tridentata spp.) habitats on which it depends. Because of these declines and the subsequent loss of habitat, knowledge concerning the juvenile ecology of sage-grouse, including natal dispersal patterns and abilities and its influences on population persistence, colonization, and connectivity are critical for the conservation planning and management of this species. The focus of this dissertation was two-fold: first, to assess the feasibility of actively collecting and hatching sage-grouse eggs from wild radiomarked sage-grouse and rearing subsequent domestically-hatched (DH) chicks from 1-10 days of age before augmenting wild sage-grouse broods (Chapter 2), and second to investigate natal dispersal in greater sage-grouse through both demographic (radio telemetry) and genetic methods.
In Chapter 3, I monitored survival and causes of mortality in wild-hatched chicks (n = 431) in wild broods (n = 115) from hatch to 16 weeks of age in the Axial Basin and Cold Springs Mountain study areas in northwestern Colorado, 2005-2007 and evaluated potentially important predictors of brood and chick survival. In addition, I monitored survival from hatch to 16 weeks of age for a cohort of DH chicks raised to 1-10 days of age in captivity (n = 116) and introduced into a subset of wild broods during this same time period. Model averaged estimates of brood and chick survival indicated that survival varied both temporally and spatially.
In Chapter 4, I captured, radiomarked, and monitored survival and recruitment of 183 transmitter-equipped juveniles (from Chapter 3) from 1 September – 31 March. Survival from September through March was similar for all juveniles, but varied by month, study area, and gender. Median dispersal distance was greater for juvenile males compared to females (M: 3.84 + 1.26 km; F: 2.68 + 0.30 km), as well as the proportion dispersing > 5 km (M: 31.6%; F: 15.5%).
In Chapter 5, I examined the patterns of dispersal, gene flow, and genetic structure at 15 leks in 6 population management zones (PMZs). Genetic analyses were largely congruent and suggested that gene flow followed an isolation-by-distance pattern, and supported male-biased dispersal findings based on demographic data (Chapter 4).
Finally, in Chapter 6, I investigated how coarse-grained landscape characteristics influenced dispersal and settlement patterns. Landscape metrics primarily differed between study areas rather than genders, and among pre-dispersal, winter, and post-dispersal landscapes. Effect of extent upon analyses depended upon the specific metric and landscape.
Period Covered: March 2005 – June 2008
PROJECT PERSONNEL:
- Thomas R. Thompson, Ph.D., University of Idaho
- A.D. Apa, Ph.D., CPW
- K.P. Reese, Ph.D., University of Idaho
All information in this report is preliminary and subject to further evaluation. Information MAY NOT BE PUBLISHED OR QUOTED without permission of the author. Manipulation of these data beyond that contained in this report is discouraged.
Northwestern Colorado Population of Greater Sage-grouse
Principal Investigator: Dr. Brett L. Walker
A. Tools for Conservation of Greater Sage-Grouse in Northwestern Colorado
Current research on greater sage-grouse (Centrocercus urophasianus) and energy development in Northwestern Colorado is being conducted by Dr. Brett L. Walker. This project is an extension of previous work that was conducted in 2005-2008 by Dr. Anthony D. Apa in collaboration with Dr. Kerry P. Reese and Tom Thompson at the University of Idaho. Current research is funded by the Colorado Parks and Wildlife, Questar Exploration and Production, Inc., the Southwest Wyoming Local Sage-Grouse Working Group, and state severance taxes. Research is being conducted with cooperation from the Vermillion Ranch and other private landowners.
In most areas slated for energy development, seasonal habitat use by sage-grouse has not yet been adequately mapped at a large enough scale or at a high enough resolution to be used in detailed planning, conservation, and mitigation efforts. This project focuses on using new advances in habitat modeling to identify and delineate critical sage-grouse breeding and wintering habitats within the proposed Hiawatha Regional Energy Development Project along the Colorado-Wyoming border. This project will also identify local- and landscape-scale habitat features important to grouse in order to develop quantitative criteria for the size and configuration and scale of sagebrush habitat required to maintain robust populations. The research is being conducted in the Zone 1 (Cold Springs/Hiawatha) core area in northwestern Colorado and south-central Wyoming, one of eleven core sage-grouse populations in Colorado (see p.295 in the Colorado Statewide Greater Sage-Grouse Conservation Plan).
Most efforts to identify key habitats for sage-grouse have used a lek-based approach to conservation because females typically nest at predictable distances around leks (e.g., 80% of females nest within 4 mi. of a lek). However, lek-based approaches will under-predict critical seasonal habitats for sage-grouse if not all lek locations are known or if birds migrate to summering or wintering areas away from leks. In contrast, lek-based approaches may also over-predict sage-grouse habitat if leks occur near unsuitable habitat for sage-grouse (e.g., aspen, forest). Identifying sage-grouse breeding habitat at higher resolution over larger areas would refine our ability to appropriately manage habitat and maintain populations. In winter, sage-grouse often move long distances to find suitable habitat and typically return to wintering areas year after year. Moreover, in migratory populations, wintering areas may be distinct from those used during the breeding season and from known lek locations. Because sage-grouse from distinct breeding areas often congregate in specific habitat types in winter, impacts to wintering habitat may have disproportionate effects on larger regional breeding populations.
Advances in habitat modeling and availability of high-resolution imagery now allow mapping of predicted probability of habitat use by sage-grouse in each season over large scales using local data from marked birds. Efforts have been made by industry and federal and state agencies to avoid, minimize, and mitigate impacts of energy development on sage-grouse. However, incorporating effects of landscape-scale habitat features on seasonal habitat use into mapping efforts will resolve current shortcomings of lek-based approaches and more tightly focus management and conservation efforts. High-resolution mapping of sage-grouse breeding habitat provides industry and federal and state agencies with a much-needed tool to simultaneously streamline planning, facilitate improved sage-grouse conservation, and quantify mitigation needs as development occurs.
Objectives of this study are to:
- Generate high-resolution maps of important sage-grouse wintering and breeding habitats within the proposed Hiawatha gas field through radio tracking efforts and regular monitoring of lekking, nesting, brood-rearing, and wintering sage-grouse.
- Evaluate the relative importance of local-scale vs. landscape-scale features in sage-grouse winter habitat selection
- Identify landscape-scale criteria for sage-grouse breeding and winter habitat.
- Assess the influence of historical energy development on current sage-grouse habitat use.
B. Comparing Demographics and Movement of Greater Sage-Grouse with VHF and GPS Transmitters in Northwestern Colorado
Growing concern for conservation of greater sage-grouse (Centrocercus urophasianus) has lead to widespread efforts to better understand sage-grouse demographic rates, movements, habitat selection, and responses to habitat manipulation and disturbance using marked birds. Almost all current research projects use very high frequency (VHF) transmitters attached to a neck collar to radio-track individuals because previous attempts using backpack-style transmitters in the 1960’s and 1970’s appeared to increase vulnerability of birds to predation. However, recent technological advances have led to commercial production of small (22-30 g), solar-powered, global positioning system (GPS) satellite transmitters that appear suitable for use with 
sage-grouse and can be mounted using a leg-loop harness (i.e., rump-mount) rather than a backpack harness. GPS transmitters have several advantages over traditional VHF collars. They collect multiple locations per day at pre-programmed times, reduce problems with on-the-ground access, eliminate observer disturbance of the bird and its flockmates, and provide extremely high-resolution data on survival, movements, habitat use, and timing of nest initiation. Solar-powered GPS transmitters need to be mounted dorsally with exposure to the sun to ensure adequate battery recharge. However, there is concern that rump-mounted transmitters may directly or indirectly reduce survival, rates of nest initiation, or movements of sage-grouse because of their similarity to backpack-style transmitters. It is important to determine whether rump-mount GPS transmitters are appropriate and safe for use prior to deploying them in sage-grouse field studies, especially in small or vulnerable populations.
The Colorado Parks and Wildlife is conducting a 1-year pilot study to compare demographic rates and movement between greater sage-grouse marked with traditional VHF neck collars versus those with rump-mounted solar GPS PTT transmitters in the proposed Hiawatha Regional Energy Development Project area in NW Colorado and SW Wyoming.
Objectives of this study are to:
The objectives of this study are to estimate and compare seasonal (breeding, summer, fall, winter) and annual (April 2009 to March 2010) survival rates, rates of nest initiation and renesting, and movements between female greater sage-grouse with GPS transmitters and VHF transmitters.
C. Using GPS Satellite Transmitters to Estimate Survival, Detectability on Leks, Lek Attendance, Inter-lek Movements, and Breeding-Season Habitat Use of Male Greater Sage-Grouse in Northwestern Colorado
Implementing effective monitoring and mitigation strategies is crucial for conserving populations of sensitive wildlife species. Concern over the status of greater sage-grouse populations has increased both range-wide and in Colorado due to historical population declines, range contraction, continued loss and degradation of sagebrush habitat, and potential federal listing of the species under the Endangered Species Act. Despite untested assumptions, lek-count data continue to be widely used as an index of abundance by state and federal agencies throughout the species' range to monitor sage-grouse populations. Lek locations are also commonly used as a surrogate to identify and protect important sage-grouse breeding and year-round habitat. However, the use of lek counts and lek locations to monitor and manage sage-grouse populations is controversial because it is unknown how closely lek-count data track actual changes in male abundance from year to year, or if lek buffers are effective at reducing disturbance to male sage-grouse and their habitat during the breeding season.
Colorado Parks and Wildlife is conducting a three-year study from 2011-2013 color-banding and deploying solar-powered GPS transmitters on male greater sage-grouse and conducting double-observer counts and resighting at leks to obtain data on male survival, lek attendance, inter-lek movements, detectability, and diurnal and nocturnal habitat use around leks during the breeding season in and near the Hiawatha Regional Energy Development project area in northwestern Colorado and south-central Wyoming.
Objectives of this study are to:
- Test whether GPS transmitters affect male greater sage-grouse survival, strutting, or lek attendance
- Use locations of GPS males to locate, verify, and count new leks
- Estimate the number of known vs. unknown leks in the study area
- Estimate the detectability of males attending leks
- Estimate daily, seasonal, and annual male lek attendance
- Estimate the frequency, timing, and distance of breeding-season movements among leks
- Estimate daily and breeding-season survival rates of GPS males
- Quantify how variation in age-specific male survival, detectability, lek attendance, inter-lek movement, and count effort affect indices and trend estimation using standard lek-count data
- Quantify male habitat use and movement around leks to test the effectiveness of different types of lek buffers for reducing disturbance to breeding males and their habitats
Conservation & Working Group Plans