The Colorado Division of Wildlife (CDOW) is continuing a study of the Parachute/Piceance/Roan (PPR) population of greater sage-grouse (
Centrocercus urophasianus) during 2007 and 2008. 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 CDOW, 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.
Seasonal Habitat Mapping and Assessment of Pinyon-Juniper Removal as Mitigation 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, CDOW 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. Since then, CDOW has identified two key conservation needs: (1) generate high-resolution maps showing concentrated seasonal-use areas; and (2) assess the value of removing encroaching pinyon-juniper from sagebrush to restore habitat as mitigation for losses due to energy development. These efforts are the result of a working relationship between CDOW, industry, private landowners, and managers in the PPR region to monitor and conserve the PPR grouse population as energy development proceeds.
A. Overview
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 face two major conservation issues: a long-term decline in habitat suitability and range contraction associated with pinyon-juniper (PJ) encroachment and rapidly spreading 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.
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.
B. Specific Objectives
- 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.
- 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.
Northwestern Colorado Population of Greater Sage-grouse
Principal Investigators: Dr. Anthony D. Apa, Dr. Brett L. Walker and Thomas Thompson
Research on Greater sage-grouse (Centocercus urophasianus) in Moffat County, Colorado, was initiated in the spring of 2005 and will continue through the spring of 2008. This research is being conducted by Anthony D. Apa in collaboration with the University of Idaho and Dr. Kerry P. Reese. The field research is being conducted by Ph.D. Student, Thomas Thompson. Funding is provided by the Colorado Division of Wildlife, National Fish and Wildlife Foundation, and Colowyo Coal Company, Ltd. The research consists of 3 components:
A. Evaluating survival, development, and movement of domestically-hatched Greater Sage-grouse chicks in wild broods from breeding season to brood break-up in northwestern Colorado
Historical and recent translocation efforts have focused on trapping reproductively active grouse from stable populations and translocating them into declining ones. Efforts at translocation have been relatively unsuccessful given the high site fidelity of adults to traditional breeding, nesting, and wintering areas, inexperience of yearling birds to new breeding grounds (i.e. lowered nest initiation rates), and the long range movement patterns that the species is capable of making across a landscape. A potential alternative to the translocation of reproductively-active adults into a population would be to supplement the broods of successfully nesting females with wild sage-grouse chicks that were hatched in captivity.
The objectives of this study are:
- To verify and evaluate the mechanisms and conditions of adoption in wild broods through the introduction of domestically-hatched chicks and observation of natural adoption rates.
- To assess the movement patterns and survivorship of successfully adopted domestically-hatched 2 and 7 day-old chicks from the natal area of the surrogate brood to chick independence and brood break-up (approximately 10 weeks of age).
- To compare the movement patterns and survivorship of domestically-hatched chicks with the movement patterns and survivorship of wild-hatched chicks in mixed and unmixed broods from the natal area of the surrogate brood to chick independence and brood break-up.
- To compare the movement patterns and survivorship of mixed and unmixed broods from the natal area of the surrogate brood to chick independence and brood break-up.
B. Demographic study of natal dispersal and survival of juvenile Greater Sage-grouse in northwestern Colorado
Past sage-grouse research has provided key guidelines for specific habitat requirements and vegetation characteristics for nesting, brood rearing, and wintering habitats needed to sustain healthy populations. However, the mechanisms, patterns, and consequences of movements between these seasonal patches, especially among juveniles during natal dispersal, and the effects of this movement on recruitment, the redistribution of individuals, and the population dynamics within and between populations remains little explored. Quantifiable data and information on juvenile dispersal and survival in the greater sage-grouse is one of the least understood aspects of this species life history.
The main objectives of this study are:
- To describe the mechanisms of brood break up in juvenile sage-grouse before dispersal
- To determine the sex-specific movement patterns of juvenile sage-grouse during natal dispersal including timing, duration, rate of movement, distances moved and proportion moved
- To determine the effects of these dispersal patterns on survival rates including causes of mortality
- To determine the movement patterns of domestically-hatched juvenile sage-grouse during natal dispersal including timing, duration, rate of movement, distances moved and proportion moved and to compare it with wild-hatched juveniles
C. Genetic study of dispersal, gene flow, and population structure of Greater Sage-grouse in northwestern Colorado
Over the last 10 years with the continued advances in conservation genetics, numerous studies have been conducted on gene flow and population structuring in grouse species. Due to unique behavioral and social adaptations, and the demographic structuring found in populations, the management and conservation of grouse species has increasingly involved the use of genetics. Additional studies have looked at the relationship between microsatellite and mitochondrial DNA and their patterns of inheritance in grouse. Grouse demographics, such as sex-biased gene flow and high levels of polygyny, can affect estimates of population structure differently depending on which genetic marker is used (i.e., uniparental vs. diparental inheritance).
The objectives of this study are:
- To determine dispersal distances, gene flow (i.e., sex-biased dispersal, source-sink dynamics), and inferences about movement in 2 populations of sage-grouse through the use of microsatellite DNA and mitochondrial DNA markers.
- To determine the genetic structure among leks complexes within and between populations (i.e., natal-lek areas, demes, subpopulations) at the regional level.
D. 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 Division of 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.
The 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.
E. 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 Division of Wildlife (CDOW) 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
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.
Conservation & Working Group Plans