Population Genetic Structuring of the Lesser Prairie-chicken
A Lesser Prairie-chicken. Photo by Dan Wundrock with permission.
The goals of this study are to characterize patterns of connectivity across the Lesser Prairie-chicken range, document levels of genetic variability among populations, identify the source population(s) for the region of recent range expansion, and determine the level of introgression with the Greater Prairie-chicken in areas where the two species overlap in distribution. This project is revealing relatively strong population structure that falls largely along ecoregion boundaries. This study also shows that the species is expanding its range into previously unoccupied or sparsely occupied habitat from the mixed grass prairie ecoregion and to a lesser extent from the sand sagebrush ecoregion (due to enrollment of agricultural land into the Conservation Reserve Program) and is actively hybridizing with Greater Prairie-chickens in the area of expansion, information that is highly relevant for management. This research is in collaboration with Texas A&M-Kingsville, Oregon State University, University of North Texas, University of Oklahoma, and the Sutton Avian Research Center.
Genetic Adaptations to Local Sagebrush Diets in Sage-grouse
Young mountain big sagebrush shown in the foreground. Photo by Dave Pyke, USGS photo gallery.
In this project we are evaluating the degree to which different Sage-grouse populations might be uniquely adapted to the local sagebrush plants, which make up the bulk of Sage-grouse diets during the fall and winter. Using target resequencing of several candidate genes, we are examining the evidence for functional genetic variation in genes that might allow Sage-grouse to specialize on locally available sagebrush varieties. This research is in collaboration with Boise State University.
Detecting annual and seasonal changes in a sagebrush ecosystem with remote sensing derived continuous fields
Homer, C.G., D.K. Meyer, C.A. Aldridge, and S. Schell
Habitat prioritization across large landscapes, multiple seasons, and novel areas: An example using Greater Sage-Grouse in Wyoming
Fedy, B.C., K.E. Doherty, C.L. Aldridge, M. O’Donnell, J.L. Beck, B. Bedrosian, D. Gummer, M.J. Holloran, G.D. Johnson, N.W. Kaczor, C.P. Kirol, C.A. Mandich, D. Marshall, G. McKee, C. Olson, A.C. Pratt, C.C. Swanson, and B.L. Walker
Animal habitat selection is an important and expansive area of research in ecology. In particular, the study of habitat selection is critical in habitat prioritization efforts for species of conservation concern. Landscape planning for species is happening at ever-increasing extents because of the appreciation for the role of landscape-scale patterns in species persistence coupled to improved datasets for species and habitats, and the expanding and intensifying footprint of human land uses on the landscape. We present a large-scale collaborative effort to develop habitat selection models across large landscapes and multiple seasons for prioritizing habitat for a species of conservation concern. Greater sage-grouse (Centrocercus urophasianus, hereafter sage-grouse) occur in western semiarid landscapes in North America. Range-wide population declines of this species have been documented, and it is currently considered as “warranted but precluded” from listing under the United States Endangered Species Act. Wyoming is predicted to remain a stronghold for sage-grouse populations and contains approximately 37% of remaining birds. We compiled location data from 14 unique radiotelemetry studies (data collected 1994–2010) and habitat data from high-quality, biologically relevant, geographic information system (GIS) layers across Wyoming. We developed habitat selection models for greater sage-grouse across Wyoming for 3 distinct life stages: 1) nesting, 2) summer, and 3) winter. We developed patch and landscape models across 4 extents, producing statewide and regional (southwest, central, northeast) models for Wyoming. Habitat selection varied among regions and seasons, yet preferred habitat attributes generally matched the extensive literature on sage-grouse seasonal habitat requirements. Across seasons and regions, birds preferred areas with greater percentage sagebrush cover and avoided paved roads, agriculture, and forested areas. Birds consistently preferred areas with higher precipitation in the summer and avoided rugged terrain in the winter. Selection for sagebrush cover varied regionally with stronger selection in the Northeast region, likely because of limited availability, whereas avoidance of paved roads was fairly consistent across regions. We chose resource selection function (RSF) thresholds for each model set (seasonal regional combination) that delineated important seasonal habitats for sage-grouse. Each model set showed good validation and discriminatory capabilities within study-site boundaries. We applied the nesting-season models to a novel area not included in model development. The percentage of independent nest locations that fell directly within identified important habitat was not overly impressive in the novel area (49%); however, including a 500-m buffer around important habitat captured 98% of independent nest locations within the novel area. We also used leks and associated peak male counts as a proxy for nesting habitat outside of the study sites used to develop themodels.A1.5-kmbuffer around the important nesting habitat boundaries included 77% of males counted at leks in Wyoming outside of the study sites. Data were not available to quantitatively test the performance of the summer and winter models outside our study sites. The collection of models presented here represents large-scale resource-management planning tools that are a significant advancement to previous tools in terms of spatial and temporal resolution.
Multiscale sagebrush rangeland habitat modeling in the Gunnison Basin of Colorado
Homer, C.G., C.L. Aldridge, D.K. Meyer, and S.J. Schell
North American sagebrush-steppe ecosystems have decreased by about 50 percent since European settlement. As a result, sagebrush-steppe dependent species, such as the Gunnison sage-grouse, have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, is needed to help maintain existing sagebrush habitats; however, products that accurately model and map sagebrush habitats in detail over the Gunnison Basin in Colorado are still unavailable. The goal of this project is to provide a rigorous large-area sagebrush habitat classification and inventory with statistically validated products and estimates of precision across the Gunnison Basin. This research employs a combination of methods, including (1) modeling sagebrush rangeland as a series of independent objective components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground measured plot data on 2.4-meter QuickBird satellite imagery in the same season the imagery is acquired; (3) modeling of ground measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of Landsat Thematic Mapper imagery (30-meter) for optimal modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution Landsat Thematic Mapper; and 6) employing accuracy assessment of model predictions to enable users to understand their dependencies. Results include the prediction of four primary components including percent bare ground, percent herbaceous, percent shrub, and percent litter, and four secondary components including percent sagebrush (Artemisia spp.), percent big sagebrush (Artemisia tridentata), percent Wyoming sagebrush (Artemisia tridentata wyomingensis), and shrub height (centimeters). Results were validated with an independent accuracy assessment, with root mean square error values ranging from 3.5 (percent big sagebrush) to 10.8 (percent bare ground) at the QuickBird scale, and from 4.5 (percent Wyoming sagebrush) to 12.4 (percent herbaceous) at the full Landsat scale. These results offer significant improvement in sagebrush ecosystem quantification across the Gunnison Basin, and also provide maximum flexibility to users to employ for a wide variety of applications. Further refinement of these remote sensing component predictions in the future will be most likely achieved by focusing on more extensive ground plot sampling, employing new high and moderate-resolution satellite sensors that offer additional spectral bands for vegetation discrimination, and capturing more dates of satellite imagery to better represent phenological variation.
Summary of science, activities, programs and policies that influence the rangewide conservation of Greater Sage-Grouse (Centrocerus urophasianus)
The Greater Sage-Grouse, has been observed, hunted, and counted for decades. The sagebrush biome, home to the Greater Sage-Grouse, includes sagebrush-steppe and Great Basin sagebrush communities, interspersed with grasslands, salt flats, badlands, mountain ranges, springs, intermittent creeks and washes, and major river systems, and is one of the most widespread and enigmatic components of Western U.S. landscapes. Over time, habitat conversion, degradation, and fragmentation have accumulated across the entire range such that local conditions as well as habitat distributions at local and regional scales are negatively affecting the long-term persistence of this species. Historic patterns of human use and settlement of the sagebrush ecosystem have contributed to the current condition and status of sage-grouse populations. The accumulation of habitat loss, persistent habitat degradation, and fragmentation by industry and urban infrastructure, as indicated by U.S. Fish and Wildlife Service (USFWS) findings, presents a significant challenge for conservation of this species and sustainable management of the sagebrush ecosystem. Because of the wide variations in natural and human history across these landscapes, no single prescription for management of sagebrush ecosystems (including sage-grouse habitats) will suffice to guide the collective efforts of public and private entities to conserve the species and its habitat.
This report documents and summarizes several decades of work on sage-grouse populations, sagebrush as habitat, and sagebrush community and ecosystem functions based on the recent assessment and findings of the USFWS under consideration of the Endangered Species Act. As reflected here, some of these topics receive a greater depth of discussion because of the perceived importance of the issue for sagebrush ecosystems and sage-grouse populations. Drawing connections between the direct effects on sagebrush ecosystems and the effect of ecosystem condition on habitat condition, and finally the connection between habitat quality and sage-grouse population dynamics remains an important goal for science, management, and conservation. This effort is necessary, despite the perception that these complicated, indirect relations are difficult to characterize and manage, and the many advances in understanding and application developed toward this end have been documented here to help inform regional planning and policy decisions.
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2011 annual report
Bowen, Z.H., C.L. Aldridge, P.J. Anderson, T.J. Assal, L.R.H. Biewick, S.W. Blecker, G.K. Boughton, S. Bristol, N.B. Carr, A.D. Chalfoun, G.W. Chong, M.L. Clark, J.E. Diffendorfer, B.C. Fedy, K. Foster, S.L. Garman, S. Germaine, M.G. Hethcoat, J. Holloway, C. Homer, M.J. Kauffman, D. Keinath, N. Latysh, D. Manier, R.R. McDougal, C.P. Melcher, K.A. Miller, J. Montag, E.M. Olexa, C.J. Potter, S. Schell, S.L. Shafer, D.B. Smith, L.L. Stillings, M.J. Sweat, M. Tuttle, and A.B. Wilson
This is the fourth annual report on the U.S. Geological Survey (USGS) science and technical assistance activities conducted for the Wyoming Landscape Conservation Initiative (WLCI). The WLCI is a partnership of Federal, State, and local agencies seeking to conserve the vast and nationally important natural resources of Southwest Wyoming in the face of rapid land-use changes. The WLCI mission is to implement a long-term, science-based program to assess and enhance the quality and quantity of aquatic and terrestrial habitats in Southwest Wyoming, while facilitating responsible development through local collaboration and partnerships. The USGS is the WLCI partner conducting most of the science and technical assistance activities that lay a foundation for conservation and management activities, whereas the land management partners (Bureau of Land Management, National Park Service, U.S. Fish and Wildlife Service, U.S. Forest Service, Wyoming Fish and Game Department, Wyoming Department of Agriculture, and local county commissioners and conservation districts) are implementing the habitat enhancement and restoration projects, conservation actions, and best management practices. In accordance with the WLCI Memorandum of Understanding (see https://my.usgs.gov/Public/WLCI/Bibliography/MOU_July_2008.pdf), the science USGS is conducting for the WLCI includes evaluating the effectiveness of habitat enhancement and restoration projects, assessing current and modeling future ecosystem conditions, and studying the short- to long-term and cumulative effects of land-use changes on target species, focal habitats (sagebrush steppe, aspen, mountain shrublands, riparian, and aquatic communities), and the overall Southwest Wyoming landscape.
The USGS WLCI Science Team has included more than 50 individuals from at least seven disciplines, including biology, geology, geography, hydrology, sociology, remote sensing/geographic information systems (GIS), and data and information management. The USGS also provides a liaison to the WLCI for the crucial work of coordinating WLCI activities and facilitating the integration of science with work conducted by WLCI partners. Tasks entail informing the development of adaptive management, best management practices, and prioritization of habitat projects based on results of USGS science and other studies; integrating existing data with new knowledge and technologies; and disseminating the outcomes of our science to partners and other stakeholders. This report and the three annual reports that preceded it describe the annual accomplishments and findings for each of our current science and technical assistance activities. Here, we highlight some of the results and products of USGS work already available to, or in use by, WLCI partners...
A sampling and analytical approach to develop spatial distribution models for sagebrush-associated species [Chapter 4]
Leu, M., S.E. Hanser, C.L. Aldridge, S.E. Nielsen, B.S. Cade, and S.T. Knick
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Sagebrush ecosystem conservation and management: Ecoregional assessment tools and models for the Wyoming Basins
Understanding multi-scale floral and faunal responses to human land use is crucial for informing natural resource management and conservation planning. However, our knowledge on how land use influences sagebrush (Artemisia spp.) ecosystems is limited primarily to site-specific studies. To fill this void, studies across large regions are needed that address how species are distributed relative to type, extent, and intensity of land use. We present a study design for the Wyoming Basin Ecoregional Assessment (WBEA) to sample sagebrush-associated flora and fauna along a land cover-human land use gradient. To minimize field costs, we sampled various taxonomic groups simultaneously on transects (ungulates and lagomorphs), point counts (song birds), and area-searches of 7.29-ha survey blocks (pellet counts, burrow counts, reptile surveys, medium-sized mammals, ant mounds, rodent trapping, and vegetation sampling of native and exotic plants)...
Multi-scale remote sensing sagebrush characterization with regression trees over Wyoming, USA: Laying a foundation for monitoring
Homer, C.G., C.L. Aldridge, D.K. Meyer, and S.J. Schell
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International Journal of Applied Earth Observation and Geoinformation