Fedy B.C.,U.S. Geological Survey |
Aldridge C.L.,Colorado State University |
Doherty K.E.,U.S. Fish and Wildlife Service |
O'Donnell M.,U.S. Geological Survey |
And 12 more authors.
Journal of Wildlife Management | Year: 2012
Animals can require different habitat types throughout their annual cycles. When considering habitat prioritization, we need to explicitly consider habitat requirements throughout the annual cycle, particularly for species of conservation concern. Understanding annual habitat requirements begins with quantifying how far individuals move across landscapes between key life stages to access required habitats. We quantified individual interseasonal movements for greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) using radio-telemetry spanning the majority of the species distribution in Wyoming. Sage-grouse are currently a candidate for listing under the United States Endangered Species Act and Wyoming is predicted to remain a stronghold for the species. Sage-grouse use distinct seasonal habitats throughout their annual cycle for breeding, brood rearing, and wintering. Average movement distances in Wyoming from nest sites to summer-late brood-rearing locations were 8.1 km (SE = 0.3 km; n = 828 individuals) and the average subsequent distances moved from summer sites to winter locations were 17.3 km (SE = 0.5 km; n = 607 individuals). Average nest-to-winter movements were 14.4 km (SE = 0.6 km; n = 434 individuals). We documented remarkable variation in the extent of movement distances both within and among sites across Wyoming, with some individuals remaining year-round in the same vicinity and others moving over 50 km between life stages. Our results suggest defining any of our populations as migratory or non-migratory is innappropriate as individual strategies vary widely. We compared movement distances of birds marked using Global Positioning System (GPS) and very high frequency (VHF) radio marking techniques and found no evidence that the heavier GPS radios limited movement. Furthermore, we examined the capacity of the sage-grouse core regions concept to capture seasonal locations. As expected, we found the core regions approach, which was developed based on lek data, was generally better at capturing the nesting locations than summer or winter locations. However, across Wyoming the sage-grouse breeding core regions still contained a relatively high percentage of summer and winter locations and seem to be a reasonable surrogate for non-breeding habitat when no other information exists. We suggest that conservation efforts for greater sage-grouse implicitly incorporate seasonal habitat needs because of high variation in the amount of overlap among breeding core regions and non-breeding habitat. Copyright © The Wildlife Society, 2012.
Fedy B.C.,University of Waterloo |
Fedy B.C.,U.S. Geological Survey |
Doherty K.E.,U.S. Fish and Wildlife Service |
Aldridge C.L.,Colorado State University |
And 16 more authors.
Wildlife Monographs | Year: 2015
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 semi-arid 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 the models. A 1.5-km buffer 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. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. © 2014 The Authors. Wildlife Monographs Published by The Wildlife Society.
Sheley R.L.,U.S. Department of Agriculture |
Vasquez E.A.,Wyoming Wildlife Consultants LLC |
Chamberlain A.-M.,Oregon State University |
Smith B.S.,U.S. Department of Agriculture
Invasive Plant Science and Management | Year: 2012
Producers facing infestations of invasive annual grasses regularly voice the need for practical revegetation strategies that can be applied across broad landscapes. Our objective was to determine the potential for scaling up the single-entry approach for revegetating medusahead-infested rangeland to broader, more heterogeneous landscape-scale revegetation of winter annual grass-infested rangeland. We hypothesized, when applied on a highly variable landscape scale, the combination of imazapic and seeding would provide highest abundance of perennial grasses and lowest amount of annual grasses. Treatments included a control, seeding of crested wheatgrass ('Hycrest') and Sandberg's bluegrass, spraying (60 g ai ha-1 imazapic), and a simultaneously applied combination of spraying and seeding. The HyCrest and Sandberg's bluegrass seeding rates were 19 and 3.4 kg ha-1, respectively. The treatments were applied to large plots (1.4 to 8 ha) and replicated five times, with each replication located in different watersheds throughout southeastern Oregon. This study shows that the single-entry approach can be scaled up to larger landscapes, but variation within establishment areas will likely be high. This procedure should reduce the costs over multientry treatment applications and make revegetating annual grass-infested rangeland across landscapes more affordable.
Lebeau C.W.,Western EcoSystems Technology Inc. |
Beck J.L.,University of Wyoming |
Johnson G.D.,Western EcoSystems Technology Inc. |
Holloran M.J.,Wyoming Wildlife Consultants LLC
Journal of Wildlife Management | Year: 2014
Greater sage-grouse (Centrocercus urophasianus) are experiencing population declines across much of their current range. Population declines are directly related to changes in greater sage-grouse fitness parameters including nest and brood success, and female survival. Reduced fitness in greater sage-grouse populations has been attributed to a decrease in habitat suitability caused by anthropogenic disturbance factors including energy extraction activities. The increased demand for renewable energy has raised concerns about the impacts of infrastructure associated with wind energy development on greater sage-grouse populations. We hypothesized that greater sage-grouse nest, brood, and adult survival would decrease with increasing proximity to wind energy infrastructure, particularly wind turbines. We monitored 95 nests, 31 broods, and identified 45 mortalities from 116 female greater sage-grouse from 2009 to 2010 at a wind energy facility in south-central Wyoming, USA. We used Cox proportional hazards regression to model nest survival and used the Andersen-Gill survival model to estimate female and brood survival relative to vegetation cover, topography, and distance to wind turbines and other anthropogenic features on the landscape. Results from our survival analysis indicated that the risk of a nest or brood failing decreased by 7.1% and 38.1%, respectively, with every 1.0km increase in distance from nearest turbine. We detected no variation in female survival relative to wind energy infrastructure. Decreased nest and brood survival was likely the result of increased predation, which may have been a product of anthropogenic development and habitat fragmentation. Future wind energy developments should consider the increased risk of nest and brood failure within habitats of close proximity to turbines. Identifying nesting and brood-rearing habitats within close proximity to proposed wind energy developments is critical when estimating potential impacts to overall population fitness. © 2014 The Wildlife Society.
Holloran M.J.,Wyoming Wildlife Consultants LLC |
Kaiser R.C.,University of Wyoming |
Hubert W.A.,University of Wyoming
Journal of Wildlife Management | Year: 2010
Sagebrush (Artemisia spp.)-dominated habitats in the western United States have experienced extensive, rapid changes due to development of natural-gas fields, resulting in localized declines of greater sage-grouse (Centrocercus urophasianus) populations. It is unclear whether population declines in natural-gas fields are caused by avoidance or demographic impacts, or the age classes that are most affected. Land and wildlife management agencies need information on how energy developments affect sage-grouse populations to ensure informed land-use decisions are made, effective mitigation measures are identified, and appropriate monitoring programs are implemented (Sawyer et al. 2006). We used information from radio-equipped greater sage-grouse and lek counts to investigate natural-gas development influences on 1) the distribution of, and 2) the probability of recruiting yearling males and females into breeding populations in the Upper Green River Basin of southwestern Wyoming, USA. Yearling males avoided leks near the infrastructure of natural-gas fields when establishing breeding territories; yearling females avoided nesting within 950 m of the infrastructure of natural-gas fields. Additionally, both yearling males and yearling females reared in areas where infrastructure was present had lower annual survival, and yearling males established breeding territories less often, compared to yearlings reared in areas with no infrastructure. Our results supply mechanisms for population-level declines of sage-grouse documented in natural-gas fields, and suggest to land managers that current stipulations on development may not provide management solutions. Managing landscapes so that suitably sized and located regions remain undeveloped may be an effective strategy to sustain greater sage-grouse populations affected by energy developments. © 2010 The Wildlife Society.
Kirol C.P.,University of Wyoming |
Beck J.L.,University of Wyoming |
Uzurbazar S.V.,Statistical and Applied Mathematical science Institute |
Uzurbazar S.V.,North Carolina State University |
And 3 more authors.
Ecological Applications | Year: 2015
Conserving a declining species that is facing many threats, including overlap of its habitats with energy extraction activities, depends upon identifying and prioritizing the value of the habitats that remain. In addition, habitat quality is often compromised when source habitats are lost or fragmented due to anthropogenic development. Our objective was to build an ecological model to classify and map habitat quality in terms of source or sink dynamics for Greater Sage-Grouse (Centrocercus urophasianus) in the Atlantic Rim Project Area (ARPA), a developing coalbed natural gas field in south-central Wyoming, USA. We used occurrence and survival modeling to evaluate relationships between environmental and anthropogenic variables at multiple spatial scales and for all female summer life stages, including nesting, brood-rearing, and non-brooding females. For each life stage, we created resource selection functions (RSFs). We weighted the RSFs and combined them to form a female summer occurrence map. We modeled survival also as a function of spatial variables for nest, brood, and adult female summer survival. Our survival models were mapped as survival probability functions individually and then combined with fixed vital rates in a fitness metric model that, when mapped, predicted habitat productivity (productivity map). Our results demonstrate a suite of environmental and anthropogenic variables at multiple scales that were predictive of occurrence and survival. We created a source-sink map by overlaying our female summer occurrence map and productivity map to predict habitats contributing to population surpluses (source habitats) or deficits (sink habitat) and low-occurrence habitats on the landscape. The source-sink map predicted that of the Sage-Grouse habitat within the ARPA, 30% was primary source, 29% was secondary source, 4% was primary sink, 6% was secondary sink, and 31% was low occurrence. Our results provide evidence that energy development and avoidance of energy infrastructure were probably reducing the amount of source habitat within the ARPA landscape. Our source-sink map provides managers with a means of prioritizing habitats for conservation planning based on source and sink dynamics. The spatial identification of high value (i.e., primary source) as well as suboptimal (i.e., primary sink) habitats allows for informed energy development to minimize effects on local wildlife populations. © 2015 by the Ecological Society of America.