Geology topics

Jill A. Shaffer

Publications and source records attributed to Jill A. Shaffer.

At least 19 recordsLinked to original sources

USGS2025

The effects of management practices on grassland birds—Field Sparrow ( Spizella pusilla )

Keys to Field Sparrow ( Spizella pusilla ) management include providing shrub-dominated edge habitat adjacent to grasslands or grasslands with a shrub component (both of which must include dense grass and moderately high litter cover) and avoiding disturbances that eliminate woody vegetation. Field Sparrows have been reported to use habitats with 16–134 centimeters (cm) vegetation height, 20–145 cm visual obstruction reading, 17–90 percent grass cover, 2–45 percent forb cover, less than 63 percent shrub cover, 3–7 percent bare ground, 14–30 percent litter cover, and 1–7 cm litter depth.

Professional Paper↗

USGS2023

The effects of management practices on grassland birds—Loggerhead Shrike (Lanius ludovicianus)

The key to Loggerhead Shrike ( Lanius ludovicianus ) management is providing open grasslands with scattered trees and shrubs for foraging, nesting, and perching. Loggerhead Shrikes have been reported to use habitats with 20–266 centimeters (cm) vegetation height, greater than or equal to (≥) 10 percent grass cover, 3–48 percent forb cover, 2–25 percent shrub cover, 3–40 percent bare ground, and 11–67 percent litter cover.

Professional Paper↗

USGS2023

The effects of management practices on grassland birds—Bobolink ( Dolichonyx oryzivorus )

Keys to Bobolink ( Dolichonyx oryzivorus ) management are providing large areas of suitable habitat (for example, native or tame grasslands of moderate vegetative height and density, low shrub density, and moderate litter and forb cover), and protecting nesting habitat from disturbance during the breeding season. Bobolinks have been reported to use habitats with 10–166 centimeters (cm) average vegetation height, 6–75 cm visual obstruction reading, 17–65 percent grass cover, 3–50 percent forb cover, less than or equal to (≤) 22 percent shrub cover, ≤38 percent bare ground, 5–39 percent litter cover, and ≤9 cm litter depth.

Professional Paper↗

USGS2023

Assessing the use of long-term lek survey data to evaluate the effect of landscape characteristics and wind facilities on sharp-tailed grouse lek dynamics in North Dakota and South Dakota

The contribution of renewable energy to meet worldwide demand continues to grow. In the United States, wind energy is one of the fastest growing renewable energy sectors. Throughout the Great Plains of the United States, wind facilities often are placed in open landscapes of high-elevation grasslands, and those same habitats support sharp-tailed grouse ( Tympanuchus phasianellus ), a resident gamebird species. To assess the feasibility of using independently derived, long-term datasets gathered in North Dakota and South Dakota to determine whether wind facilities affected lek metrics, the U.S. Geological Survey obtained six datasets and identified 37 study sites, 9 of which contained wind turbines at varying densities. The association between explanatory variables that described geographic, landscape, and climatic attributes with two primary response metrics that described lekking activity within study sites—lek density (leks per square kilometer) and mean number of males per lek—was examined. The explanatory variables included number of turbines, geographic location, elevation, land-cover attributes available from satellite-derived land-cover data, soil moisture, precipitation, and temperature. Sampling units consisted of township-sized blocks, and lek information came from roadside surveys. Low sample sizes of constructed wind facilities available at the time of analysis did not lend itself to advanced statistical techniques, such as employing a rigorous design structure or assessing accuracy on landscape, geographic, or climatic variables. Given the quality of the data, the estimates obtained for lek density and mean number of males per lek should be considered approximations; however, these estimates have value in designing future studies, such as providing estimates for power analyses to determine sufficient sample size. No strong associations were found between the included explanatory variables and response variables (when these variables were measured as described in this report for township-sized blocks). The strongest association was that lek density and mean number of males per lek increased from South Dakota to North Dakota. Owing to the highly unbalanced distribution of turbine and nonturbine study sites across the study area, the analysis with wind turbines was inconclusive. The constraints under which the analysis can be used and the limitations of the independently derived datasets in attempted applications are discussed.

North Dakota, South Dakota↗

USGS2023

The effects of management practices on grassland birds—Dickcissel ( Spiza americana )

Keys to Dickcissel ( Spiza americana ) management include providing dense, moderate-to-tall vegetation, particularly with a well-developed forb component, and moderately deep litter. Dickcissels have been reported to use grassland habitats with 4–166 centimeters (cm) average vegetation height, 6–85 cm visual obstruction reading, 11–68 percent grass cover, 1–86 percent forb cover, less than or equal to (≤) 10 percent shrub cover, less than (<) 27 percent bare ground cover, <30 percent litter cover, and ≤ 6 cm litter depth.

Professional Paper↗

USGS2023

The effects of management practices on grassland birds—Golden Eagle (Aquila chrysaetos)

Keys to Golden Eagle ( Aquila chrysaetos ) management in western North America’s grasslands, particularly those of the Great Plains region, include maintaining open, mostly undeveloped landscapes that sustain at least modest population levels of suitable prey (most typically rabbits [Leporidae] and prairie dogs or ground squirrels [Sciuridae]); safeguarding nesting territories (that is, breeding areas), especially nest structures within territories, from human disturbances; mitigating major sources of anthropogenic mortality, particularly electrocution on powerlines, shooting, collisions with structures and vehicles, and poisoning by lead and rodenticides; and averting climate change.

Professional Paper↗

USGS2023

The effects of management practices on grassland birds—Clay-colored Sparrow ( Spizella pallida )

Keys to Clay-colored Sparrow ( Spizella pallida ) management include providing grasslands with a shrub or forb component or shrub-dominated edge habitat, which includes dense grass and moderately high litter cover, and avoiding disturbances that completely eliminate woody vegetation. Clay-colored Sparrows have been reported to use habitats with 20–186 centimeters (cm) average vegetation height, 3–50 cm visual obstruction reading, 15–74 percent grass cover, 5–23 percent forb cover, less than 30 percent shrub cover, 1–20 percent bare ground, 10–63 percent litter cover, and less than or equal to 5 cm litter depth.

Professional Paper↗

USGS2022

Understanding the Avian-Impact Offset Method—A tutorial

Biodiversity offsetting, or compensatory mitigation, is increasingly being used in temperate grassland and wetland ecosystems to compensate for unavoidable environmental damage from anthropogenic disturbances such as energy development and road construction. Energy-extraction and -generation facilities continue to proliferate across the natural landscapes of the United States, yet mitigation tools to ameliorate the negative behavioral effects on wildlife from these types of facilities are rarely implemented. Scientists from the U.S. Geological Survey conducted a 10-year before-after-control-impact (commonly referred to as BACI) study that evaluated the displacement effects of wind facilities on breeding grassland birds. The study determined behavioral avoidance for 7 of 9 species. This research is notable because of its design, geographical scope, and duration, which allowed for the determination of immediate, short-term effects; delayed or sustained effects; and discrete distances at which effects occurred. In addition, the U.S. Fish and Wildlife Service and Ducks Unlimited conducted a 3-year concurrent-year paired-reference study to determine behavioral avoidance for five species of dabbling ducks. By quantifying displacement rate from these two studies, U.S. Geological Survey and U.S. Fish and Wildlife Service scientists developed the Avian-Impact Offset Method (AIOM) to quantify and compensate for loss in value of breeding habitat. The AIOM converts the biological value (that is, number of bird pairs) lost by way of avoidance and estimates the site-specific number of hectares of grasslands and number of wetlands needed to compensate for displaced pairs of grassland birds and waterfowl. By converting biological value to traditional units of measure in which land is described and purchased or sold, the AIOM lends itself readily to the delivery of offsetting measures such as easement protections and restoration projects. The AIOM tool is applicable to wind, solar, oil, gas, and transportation infrastructure. This tutorial was designed to increase awareness of the AIOM and to promote its proper application. The tutorial is divided into four sections, each of which explains a discrete topic concerning aspects of behavioral displacement. The first section provides geographical and biological context, and the second section describes the field and statistical methods and results. The third section provides step-by-step instructions for applying the AIOM to several scenarios involving grassland birds or waterfowl at wind or oil facilities. The fourth section describes decision-support tools created to implement the AIOM. The appendices provide the actual field protocols constituting the methods for the research, provide detailed results by species and wind facility for that research, and provide detailed instructions for downloading and applying the decision-support tools.

Open-File Report↗

USGS2022

The effects of management practices on grassland birds—Burrowing Owl ( Athene cunicularia hypugaea )

Keys to Burrowing Owl ( Athene cunicularia hypugaea ) management include providing areas of short, sparse vegetation and maintaining populations of prey species and of burrowing mammals to ensure availability of burrows as nest sites. In particular, the conservation of black-tailed prairie dog ( Cynomys ludovicianus ) and Richardson’s ground squirrel ( Urocitellus richardsonii ) colonies is vital to the preservation of Burrowing Owls on the Great Plains. Burrowing Owls have been reported to use habitats with less than 31 centimeters (cm) average vegetation height, 5–12 cm visual obstruction reading, 12–36 percent grass cover, 29–45 percent forb cover, 1–11 percent shrub cover, 11–58 percent bare ground, and 6–27 percent litter cover.

Professional Paper↗

USGS2022

Limited land base and competing land uses force societal tradeoffs when siting energy development

As human populations grow, decisions regarding use of the world's finite land base become increasingly complex. We adopted a land use–conflict scenario involving renewable energy to illustrate one potential cause of these conflicts and resulting tradeoff decisions. Renewable energy industries wishing to expand operations in the United States are limited by multijurisdictional regulations in finding developable land. Interest groups entreat industries to avoid land for various reasons, including avoidance of prime wildlife habitat in accordance with an “avoidance-first” mitigation strategy. By applying a uniform set of rules for renewable energy facilities to the Prairie Pothole Region and portions of the Northern Great Plains, we evaluated the effects of regulations and avoidance of prime wildlife habitat on the amount of land available for development. In our scenario, existing regulations excluded 39% of the project area from potential development, with human infrastructure accounting for 30% (10–66% among states), whereas federally protected species accounted for < 1% at project area and state levels. Unregulated lands accounted for 61% of the project area, with conservation areas predicted as high-quality sites for breeding grassland birds and waterfowl and for migrating whooping cranes Grus americana accounting for 19% within the project area (6–27% among states). This model demonstrated a limited land base available for new development when accounting for regulations and concerns of a subset of societal interest groups. Additional interest groups likely will have different and competing concerns, further emphasizing the complexity of future land-use decisions as the available land base for development diminishes.

Journal of Fish and Wildlife Management↗

USGS2022

The effects of management practices on grassland birds—Greater Prairie-Chicken ( Tympanuchus cupido pinnatus )

The keys to Greater Prairie-Chicken ( Tympanuchus cupido pinnatus ) management are maintaining expansive grasslands; preventing populations of Greater Prairie-Chickens from becoming small and isolated; managing grasslands to maintain proper grassland height, density, and vigor; and reducing woody plant invasion and excessive litter buildup. Within these grasslands, areas should contain short herbaceous cover for lek sites; tall residual grasses for nesting; and disturbed habitats for broods with adequate vegetation regrowth that provides insects for food and cover from predators and weather. This account does not address population or harvest management but rather focuses on habitat management. Greater Prairie-Chickens have been reported to use habitats with 5–113 centimeter (cm) average vegetation height, 5–40 cm visual obstruction reading, 18–95 percent grass cover, 1–35 percent forb cover, <45 percent litter cover, <5 percent shrub cover, 3–25 percent bare ground, and <12 cm litter depth.

Professional Paper↗

USGS2021

The effects of management practices on grassland birds—Short-eared Owl (Asio flammeus)

The key to Short-eared Owl ( Asio flammeus ) management is providing large grasslands and wetlands, particularly those that can support high densities of voles ( Microtus species). Short-eared Owls have been reported to use habitats with 30–90 centimeters (cm) average vegetation height, 7–47 cm visual obstruction reading, 31–85 percent grass cover, 8–26 percent forb cover, less than 18 percent shrub cover, 43 percent litter cover, and 1–2 cm litter depth.

Professional Paper↗

USGS2021

The effects of management practices on grassland birds—Grasshopper Sparrow ( Ammodramus savannarum )

The key to Grasshopper Sparrow ( Ammodramus savannarum ) management is providing large areas of contiguous grassland of intermediate height with moderately deep litter and low shrub density. Grasshopper Sparrows have been reported to use habitats with 8–166 centimeters (cm) average vegetation height, 4–80 cm visual obstruction reading, 12–95 percent grass cover, 4–40 percent forb cover, less than 35 percent shrub cover, less than or equal to (≤) 38 percent bare ground, 5–61 percent litter cover, and ≤9 cm litter depth.

Professional Paper↗

USGS2021

Migrating whooping cranes avoid wind-energy infrastructure when selecting stopover habitat

Electricity generation from renewable-energy sources has increased dramatically worldwide in recent decades. Risks associated with wind-energy infrastructure are not well understood for endangered whooping cranes or other vulnerable crane populations. From 2010 to 2016, we monitored 57 whooping cranes with remote-telemetry devices in the United States Great Plains to determine potential changes in migration distribution (i.e., avoidance) caused by presence of wind-energy infrastructure. During our study, the number of wind towers tripled in the whooping crane migration corridor and quadrupled in the corridor’s center. Median distance of whooping crane locations from nearest wind tower was 52.1 km, and 99% of locations were >4.3 km from wind towers. A habitat selection analysis revealed that whooping cranes used areas ≤5.0 km (95% CI = 4.8–5.4) from towers less than expected (i.e., zone of influence) and that whooping cranes were 20 times (95% CI: 14–64) more likely to use areas outside compared to adjacent to towers. Eighty percent of whooping crane locations and 20% of wind towers were located in areas with the highest relative probability of whooping crane use based on our model, which comprised 20% of the study area. Whooping cranes selected for these places, whereas developers constructed wind infrastructure at random relative to desirable whooping crane habitat. As of early 2020, 4.6% of the study area and 5.0% of the highest-selected whooping crane habitat were within the collective zone of influence. The affected area equates to habitat loss ascribed to wind-energy infrastructure; losses from other disturbances have not been quantified. Continued growth of the whooping crane population during this period of wind infrastructure construction suggests no immediate population-level consequences. Chronic or lag effects of habitat loss are unknown but possible for long-lived species. Preferentially constructing future wind infrastructure outside of the migration corridor or inside of the corridor at sites with low probability of whooping crane use would allow for continued wind-energy development in the Great Plains with minimal additional risk to highly selected habitat that supports recovery of this endangered species.

Kansas, Montana, Nebraska, North Dakota, Oklahoma,↗

USGS2021

The effects of management practices on grassland birds—Lark Sparrow (Chondestes grammacus)

Keys to Lark Sparrow ( Chondestes grammacus ) management include providing open grasslands with sparse-to-moderate herbaceous and litter cover and a woody component and allowing occasional burning or moderate grazing. Lark Sparrows have been reported to use habitats with 10–63 centimeters (cm) average vegetation height, 10–54 percent grass cover, 9–25 percent forb cover, 4–18 percent shrub cover, 16–38 percent bare ground, 12–45 percent litter cover, and less than or equal to 1 cm litter depth.

Professional Paper↗

USGS2020

Quantifying and addressing the prevalence and bias of study designs in the environmental and social sciences

Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental datasets, that these types of designs usually give less biased estimates than simpler observational designs. We propose a model-based approach to combine study estimates that may suffer from different levels of study design bias, discuss the implications for evidence synthesis, and how to facilitate the use of more credible study designs.

Nature Communications↗

USGS2020

Improving the ability to include freshwater wetland plants in process-based models

Considerable effort and resources have been placed into conservation programs designed to reduce or alleviate negative environmental effects of crop production and into evaluation of the benefits of these programs. Wetlands are an important source of ecosystem services, but modeling wetland plants is an emerging science. To date, wetland plant growth has not been explicitly accounted for in ecosystem service models that quantify conservation program effects. As part of an effort to more accurately simulate wetland plants within process-based models, we expanded upon plant growth data collected in an earlier effort with additional sampling at two of four previously sampled areas, and included a fifth sampling site. We then used data from the five sites spanning five years as wetland plant parameters at both the species and functional group levels for the Agricultural Land Management Alternative with Numerical Assessment Criteria (ALMANAC) model. In addition to individual species, modelers are interested in functional groups representing a collection of species because it is unrealistic to model every species occurring in an ecosystem. ALMANAC simulations were completed at three sites for both individual wetland plant species and functional groups. At each site, simulated plant yields were within 1 Mg ha –1 (±7%) of measured values ( r 2 = 0.99). Multisite species simulated yields were within 37% of measured values ( r 2 = 0.95). Functional groups performed as well as individual species simulations. Functional group simulated yields were within 1 Mg ha –1 (±5%) of measured yields. Plant growth is a major component of these wetland ecosystems, and ALMANAC verified wetland plant parameters support more accurate assessments of conservation programs and practices on the influence of wetland ecosystems embedded within agricultural fields. The improved plant parameters we provide here will be transferred to other process-based models that focus on other ecosystem components such as soil and water effects, facilitating wetland evaluations across the United States and elsewhere.

California, Delaware, Maryland, North Dakota, Texa↗

USGS2020

The effects of management practices on grassland birds—Brewer’s Sparrow ( Spizella breweri breweri )

Keys to Brewer’s Sparrow ( Spizella breweri breweri ) management include maintaining extensive, unfragmented patches of suitable breeding habitat; reducing conifer cover and height; preventing the invasion of conifers and nonnative plants, especially cheatgrass (downy brome [ Bromus tectorum ]); minimizing disturbance to soil; and restricting the use of pesticides and herbicides during the breeding season (April–July). Brewer’s Sparrows have been reported to use breeding habitats with 12–170 centimeter (cm) vegetation height, 2–34 cm visual obstruction reading, 1–74 percent grass cover, less than (<) 19 percent forb cover, 1–65 percent shrub cover, 1–75 percent bare ground, 2–61 percent litter cover, and <1 cm litter depth. During post-fledging dispersal in July, Brewer’s Sparrow adults and young may shift habitat use to nearby aspen ( Populus species [spp.]), riparian shrub, or deciduous mountain shrub habitats, so these habitats also may be important for management.

Professional Paper↗