The Project: What We Are Doing And Why

Development of a Species Conservation Plan for Greater Sage-Grouse in Mono County, California

Principal Investigators:

Michael L. Casazza, United States Geological Survey (USGS), Western Ecological Research Center (WERC), Dixon Field Station, 6924 Tremont Rd. Dixon, CA 95620 (707)678-0682 ext. 629 Mike_Casazza@usgs.gov

Products:

2005 Progress Report (10MB pdf)
2003 Progress Report (10MB pdf)

Acknowledgements:

Funding for this work has primarily been provided by the California Department of Fish and Game, the US Fish and Wildlife Service, and the Western Ecological Research Center of the US Geological Survey. Partners and cooperators include:

• University of Nevada Reno
• Quail Unlimited
• US Forest Service
• Nevada Department of Wildlife
• Los Angeles Department of Water and Power
• Bi-State Sage Grouse Conservation Team

Several local populations of sage grouse have been previously identified in Mono County, including the Jackass Spring area, the Fales/Wheeler area, Parker Meadows, Long Valley, the Mono Basin, the White Mountains, and the Bodie Hills (Figure 1). The basis for defining a local population for purposes of this study plan is known concentrations of birds occupying local areas which are not known to interchange regularly with sage grouse in other local concentration areas. Complexes of lek (breeding display sites – strutting grounds) sites have been monitored for many years in the Long Valley and Bodie Hills, with additional leks identified in the Fales/Wheeler area and Parker Meadows. Sage grouse are known to occur in the Jackass Spring area and the White Mountains, but currently used lek sites have not been identified. There are records of historic lek sites in the White Mountains (CDFG unpublished data). These populations have been defined primarily on known lek sites and brood rearing areas. However, movements between these areas are not well known and wintering areas have not been sufficiently studied.

Sage grouse face a variety of risks to their continued viability in each of these areas. Leks in the Fales/Wheeler Flat area are found on a combination of private and United States Forest Service (USFS) lands. Private lands in this area are facing increased pressure from housing development. Habitat and populations on adjacent USFS lands could also be affected by development on private lands. Until recently, leks in the Parker area had not been identified and little is known about the movement patterns of this local population. Sage grouse in the area of Jackass Spring near the Nevada border on the northern end of Mono County have not been studied, with very little existing information on this local population and no documented lek sites. A recent proposal to expand the Mammoth-Yosemite airport to accommodate large commercial jet aircraft could have tremendous growth-inducing impacts to the region and may negatively impact the Long Valley sage grouse population. Proposed developments associated with the airport expansion include residential zones, commercial retail, and a hotel. These developments, located on property owned by the Town of Mammoth Lakes, could have significant impacts on sage grouse found on adjacent Bureau of Land Management (BLM) and City of Los Angeles-owned lands within Long Valley. Additional private land in Long Valley contains key sage grouse use areas. Similarly, development of private parcels and mining proposals on public (BLM) lands may impact the sage grouse population in the Bodie Hills. Ongoing research being conducted by the BLM on the Bodie Hills population may be able to address some of the concerns in this local area, as well as a proposed BLM study in the Long Valley area.

Much of the existing sage grouse literature focuses on maintenance of habitat on public lands (Wisdom et al. 2002, Connelly et al. 2000) while very little information is available regarding maintenance of habitat on private lands under threat of development. Because so many different agencies are involved in the development process, it is difficult to devise mitigation measures likely to result in the conservation of sage grouse. Projects are reviewed on a case-by-case basis and mitigation measures that are piecemealed may not be adequate on a larger regional scale.

An effort to develop a comprehensive conservation plan inclusive of sage grouse in Mono County is currently underway via the Nevada Sage Grouse Conservation Strategy (2001). Such a plan is needed to address overall pressures to sage grouse populations and habitat from various land and recreational uses now and in the future. To effectively complete such a plan, a comprehensive understanding of sage grouse populations is required. Identification of lek sites, nesting areas, brood rearing areas, wintering areas, and seasonal movements between these areas are not currently well known. A more complete understanding of the ecological consequences of alterations in the quantity, quality, and juxtaposition of these habitats to the population dynamics is required to recommend strategies for conserving sage grouse throughout the landscape. Local strategies will also be required to recommend key pieces of property for protection, and to suggest appropriate mitigation measures for proposed development.

A wealth of information is already available to begin building the conservations plan from previous monitoring and research. However, information gaps exist for sage grouse in Mono County, including information on migratory patterns, habitat use, and factors affecting survival and recruitment. This research is proposed to identify and gather critical information to develop a more comprehensive and effective conservation plan throughout the county.

Sage grouse ecology has been documented and summarized in several recent publications (Connelly et al. 2000, Schroeder et al. 1999). Numerous telemetry studies have documented the existence of different migration strategies for sage grouse including populations that have; 1) distinct winter, breeding and summer areas; 2) distinct summer areas and integrated winter and breeding areas; 3) distinct winter areas and integrated summer and breeding areas; and 4) non-migratory populations (Connelly et al. 2000). The migration strategies for Mono County sage grouse are not well known. Habitat management guidelines for sage grouse have been developed for winter, summer and breeding habitats (Connelly et al. 2000). Knowledge of movement patterns are needed to identify habitat use areas within Mono County and evaluate future management strategies based on sage grouse habitat requirements. The compilation of existing data on sage grouse populations in Mono County, combined with additional research conducted on local populations which have been little studied, will contribute significantly to a comprehensive sage grouse conservation plan for Mono County.

Goal: Develop a species conservation plan for greater sage grouse in Mono County.

Objectives:

1. Participate in development of the Bi-State Conservation Plan
2. Compile and synthesize existing sage grouse data (including reports, literature and GIS coverages/databases) for Mono County.
3. Document seasonal movements of sage grouse in Mono County.
4. Identify specific habitats critical to sage grouse in Mono County.
5. Determine survival rates and identify causal factors of mortality for sage grouse in Mono County.
6. Determine nesting success and brood survival of sage grouse in Mono County.
7. Identify sage grouse lek sites in Mono County.

Study Area: Mono County, California. Our efforts will concentrate on sage grouse in areas where information is most needed following compilation and review of existing data as identified in objective 1. At this time, we have identified the following information as most critical in the county. We will document movements and population demographics in the Jackass Spring area, the Fales/Wheeler Flats area, and Parker Meadows area (Figure 1). We will conduct lek searches in the White Mountains. We will coordinate our research efforts with ongoing research by the BLM in the Bodie Hills area and proposed research by the BLM in the Long Valley area to better understand overall population dynamics of sage grouse within the county.

Methods:

Bi-State Conservation Plan (Objective 1): A comprehensive species conservation plan for sage grouse populations throughout Nevada and California is currently being developed via the Nevada Sage Grouse Conservation Strategy (Governor Guin’s Sage Grouse Conservation Planning Team 2001). The Bi-State local planning area includes populations of sage grouse along the California-Nevada border, in and surrounding Mono County. Local populations have been described and placed into 6 population management units (PMU’s): including Desert Creek/Fales, Bodie Hills, South Mono Basin (Includes Long Valley), Pine Nut, White Mountains, and Mt. Grant. This is a consensus-built conservation plan developed by local working groups including federal, state, and local regulatory and land-management agencies, non-government organizations, ranchers, private landowners, and Native American tribes. Local population risk assessment and conservation strategies are being developed in each PMU, for inclusion in a cooperative Mono County sage grouse conservation plan.

We will participate in the conservation planning process currently underway by providing technical assistance as needed (see objective 2). The State of Nevada has set a deadline of December 2003, for a final statewide plan, including the Bi-State effort. Deficiencies in producing an overall plan are currently being identified during this process, resulting from the lack of information regarding some of the issues discussed above. We will continue the conservation planning process through the end of this contract to integrate our research findings. We will help produce an updated plan for Mono County, using the local working group already established in the Bi-State effort, to include the current state of knowledge and any new research findings by the end of 2005.

Existing Data Review (Objective 2): We will conduct a comprehensive review of existing data for sage grouse populations in Mono County during December 2002 through May of 2003. We will gather all applicable information from local agencies in this region, including the California Department of Fish and Game (CDFG), BLM, USFS, and any other available sources. Considerable existing data are currently available, but they are in various formats including field notes, unpublished progress reports, GIS databases, as well as some published literature. We will incorporate all of this information into standard databases, consistent with guidelines established in published literature and current standards being developed in the collection and interpretation of sage grouse data through the Western Association of Fish and Wildlife Agencies Sage Grouse Technical Committee. We will complete a summary of the current knowledge base on sage grouse in Mono County. Data gathered during this review will be integrated into the appropriate PMU via the coordinators for each PMU.

Radio-telemetry (Objectives 3-7): Sage grouse will be captured using spotlighting techniques (Wakkinen et al. 1992, Giesen et al. 1982) beginning in March of 2003, with a goal to maintain about 30 female and 15 male radio-marked grouse during the study. We will attempt to mark at least 10 yearling male grouse at > 3 different leks to optimize our chances for identifying new lek sites within the study areas. Juvenile male birds tend to be more mobile and will be more likely to lead us to new lek sites (Apa 2003, pers. comm.). Birds will be captured on roosts surrounding lek sites in the spring and near water sources in the fall. Captured birds will be aged, weighed, sexed (Beck et al. 1975), banded, and fitted with a necklace-mounted radio transmitter with an activity sensor (Riley and Fistler 1992, Sveum et al. 1998). The birds will then be released at the point of capture and the location marked using a Global Positioning System (GPS). All bird locations will be recorded in Universal Transversal Mercator (UTM) units.

Seasonal Movements (Objective 3): Each radio-marked grouse will be relocated at least twice each week to determine seasonal movements and habitat use throughout the year. Birds will be monitored more frequently during the breeding season than other seasons (see objective 4) using a combination of aerial, truck and hand-held telemetry techniques. Aerial telemetry will be used to locate missing birds and to identify bird locations when ground conditions prohibit vehicle or hand-held telemetry observations (e.g. heavy snow).

Habitat Selection (Objective 4): Vegetation and site characteristics (slope, aspect, snow depth, vegetation height above snow, etc,) will be recorded for each identified bird location. Habitats will be classified according to guidelines given in Sather-Blaire et al. (2000) and modified in the Nevada Sage Grouse Conservation Strategy (Governor Guin’s Sage Grouse Conservation Planning Team 2001) based on general characteristics of the sagebrush habitat present. Micro-habitat selection will be determined by comparing habitat use to availability, with emphasis on nest sites, brood rearing sites, and wintering sites. Species composition and vegetation characteristics will be measured at use sites to determine habitat use as described below. Habitat availability will be estimated by measuring the same variables at randomly sampled sites stratified within similar seasonal habitats (Drut et al. 1994). We will measure shrub canopy cover using two perpendicular 10m transects (Canfield 1941, Drut et al. 1994) and understory and grasses using 5 uniformly spaced rectangular plots of 20 by 50cm along each transect (Daubenmire 1959). We will record canopy cover, shrub height, maximum grass height, grass droop height and classify grasses as short or tall (Wakkinen 1990, Gregg et al. 1994). We will also measure vertical vegetation cover at the nest site using a Robel pole and two additional readings along each 10m transect (Robel et al. 1970, Sveum et al. 1998).

We will determine seasonal home range areas for individual birds using the adaptive kernel home range method (Worton 1989). Radio-locations will be classified as breeding, summer, or winter and maintained in a GIS database using ARC/INFO and Arc View software (ESRI, Inc.). We will compare macro- habitat use with habitat availability based on GAP vegetation maps available through the US Geological Survey (http://sagemap.wr.usgs.gov/datalist_state2.asp) (or the best available habitat coverages at the time of analysis) using compositional analysis (Aebischer et al. 1993).

Survival Rates (Objective 5): Transmitters will be equipped with mortality sensors that will double the pulse rate of the transmitter after 8 hours of no movement. When a mortality signal is encountered, crews will recover the birds as quickly as possible to maximize the chances that a cause of death can be determined. Intact carcasses will be sent to the National Wildlife Health Center in Madison, WI to help determine the cause of mortality. We will use the program MARK (Cooch and White 1998) and AIC (Akaike 1985, Burnham and Anderson 1992) to model survival covariates and estimate survival during 3 intervals: (1) breeding (2) summer/brood rearing and (3) winter.

Nest/Brood Success (Objective 6): Breeding success measures will be monitored with specific protocols beginning in March and continuing through August (Schroeder 1997). Locations of female sage grouse will be determined to within approximately 30 m every 3 days throughout the nesting season using a portable receiver and hand-held antenna (Schroeder 1997). Care will be taken to not disturb the hens. Transmitters will be equipped with an activity sensor and we will assume hens are nesting when movements become localized (Connelly et al. 1993) and/or activity sensors indicate long periods of inactivity. By locating the female and her nest site, data can be collected on timing of incubation, nest failure, and nest success. Variation in transmitter signal frequency will help indicate female behavior (Schroeder 1997). Nest locations will be mapped using our GIS.

When monitoring indicates that a hen has terminated the nesting effort, nest fate will be determined by examining the shell membrane and broken eggshells (Connelly et al. 1993). If the membrane is still firmly attached to the shell, the nest will be classified as depredated. A membrane that is detached from the eggshell will be classified as a successful hatch (Klebenow 1969, Gregg et al. 1994). We will determine clutch size when possible by counting eggshells following a successful hatch or the destruction of the nest within 5 days of the females’ departure from the nest site (Schroeder 1997). We will calculate nest success as the percent of all nests that hatched > 1 egg (Schroeder 1997). Breeding success will be estimated as the percent of females that hatched > 1 chick during the breeding season, including re-nesting efforts.

We will locate radio-marked hens with broods four times each week to help evaluate brood rearing habitat (Gregg et al. 1994). Weekly locations will be divided into three time periods: morning (>4 hours after sunrise), mid-day (>4 hours after sunrise to > 4 hours before sunset), and evening (< 4 hours before sunset) (Dunn and Braun 1986). We will estimate fledging success as the percent of females that produces > 1 chick > 50 days old (Schroeder 1997).

Lek site identification (Objective 7): Documentation of lek locations is essential in a complete understanding of the spatial population dynamics of sage grouse. Peak male attendance is also commonly used to assess sage grouse population trends. All known leks will be recorded in our GIS database. We will systematically search for new leks in areas that birds are suspected to inhabit but lek sites have not been identified, such as the White Mountains and Jackass Spring. We will employ both aerial and ground reconnaissance to attempt to locate lek sites during March and April of 2003 and 2004. Birds trapped on springs in the fall will also be used to help identify new lek sites. Juvenile male birds fitted with transmitters will be tracked regularly during the breeding season and their locations will be plotted on a bi-weekly basis to help identify potential new lek sites. We will record coordinates for lek sites and maintain all lek locations in GIS and Microsoft Access databases. Movements of radio-marked birds will be analyzed relative to lek sites, and we will document visits to leks by radio-marked individuals. We will calculate distances traveled by radio-marked individuals between lek sites and other seasonal habitats, which will also help identify critical travel corridors for habitat protection.

Data Archiving: All telemetry data will be entered into a Microsoft Access database and maintained at the Dixon Field Station. Back-up copies of data will be stored on the local Snap-Server. Additionally, a back-up copy of the data will be stored on compact discs and provided to CDFG. We will store all GIS databases at the Dixon Field Station GIS laboratory with the appropriate metadata files included. The data will also be submitted to BIOS (Biogeographic Information and Observation System), managed by the California Department of Fish & Game.

Hazard Assessment/Safety Certification: Personnel will operate vehicles in potentially hazardous weather and road conditions, and conduct fieldwork under variable environmental conditions. Telemetry flights will primarily be conducted by CDFG pilots and aircraft which have been OAS certified. Personnel will be instructed in safe operation of motor vehicles and ATVs.

Animal Care and Use: Work during this study requires the capture and radio-marking of sage grouse. Birds will be handled humanely and released at the point of capture within a few minutes. Appropriate banding and handling permits will be acquired and work will follow approved animal care policy.

Literature Cited:

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Beck, T.D., R.B. Gill, and C.E. Braun. 1975. Sex and age determination of Sage Grouse from wing characteristics. Game Inf. Leafl. 49 (revised). Colorado Division of Wildlife. 4pp.

Braun, C.E. 1998. Sage Grouse declines in western North America: what are the problems? Proc. West. Assoc. State Fish and Wildl. Agencies 78: 139-156.

Burnham, K.P., and D.R. Anderson. 1992. Data-based selection of an appropriate biological model: the key to modern data analysis. Pages 16-30 in D.R. McCullough and R.H. Barrett, eds., Wildlife 2001: populations. Elsevier, New York.

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Connelly, J. W., R. A. Fischer, A. D. Apa, K. P. Reese, and W. L. Wakkinen. 1993. Renesting by sage grouse in Southeastern Idaho. The Condor 95:1041-1043.

Connelly, J. W. and C. E. Braun. 1997. Long-term changes in Sage Grouse Centrocercus urophasianus populations in western North America. Wildl. Biol. 3:229-234.

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Drut, M.S., J.A. Crawford, and M.A. Gregg. 1994. Brood habitat use by Sage Grouse in Oregon. Great Basin Naturalist. 54(2):170-176.

Dunn, P.O., and C.E. Braun. 1986. Summer habitat use by female and juvenile Sage Grouse. Journal of Wildlife Management. 50:228-235.

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