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At least 757 records · Page 42Linked to original sources

USGS2023

Integrated rangeland fire management strategy actionable science plan completion assessment: Invasives topic, 2015–20

Loss and degradation of sagebrush rangelands due to an accelerated invasive annual grass-wildfire cycle and other stressors are significant management, conservation, and economic issues in the western United States. These sagebrush rangelands comprise a unique biome spanning 11 states, support over 350 wildlife species, and provide important ecosystem services that include stabilizing the economies of western communities. Impacts to sagebrush ecosystem processes over large areas due to the annual grass-wildfire cycle necessitated the development of a coordinated, science-based strategy for improving efforts to achieve long-term protection, conservation, and restoration of sagebrush rangelands, which was framed in 2015 under the Integrated Rangeland Fire Management Strategy (IRFMS). Central to this effort was the development of an Actionable Science Plan (Plan) that identified 37 priority science needs (Needs) for informing the actions proposed under the 5 topics (Fire, Invasives, Restoration, Sagebrush and Sage-Grouse, Climate and Weather) that were part of the collective focus of the IRFMS. Notable keys to this effort were identification of the Needs co-produced by managers and researchers, and a focus on resulting science being “actionable.” Substantial investments aimed at fulfilling the Needs identified in the Plan have been made since its release in 2016. While the state of the science has advanced considerably, the extent to which knowledge gaps remain relative to identified Needs is relatively unknown. Moreover, new Needs have likely emerged since the original strategy as results from actionable science reveal new questions and possible (yet untested) solutions. A quantifiable assessment of the progress made on the original science Needs can identify unresolved gaps and new information that can help inform prioritization of future research efforts. This report details a systematic literature review that evaluated how well peer-reviewed journal articles and formal technical reports published between January 1, 2015, and December 31, 2020, addressed six needs (hereinafter “Needs”) identified under the Invasives topic in the Plan. The topic outlined research Needs related to the control of invasive plant species in sagebrush rangelands, with a special emphasis on invasive annual grasses. We established the level of progress towards addressing each Need following a standardized set of criteria, and developed summaries detailing how research objectives nested within Needs identified in the Plan (“Next Steps”) were either addressed well, partially addressed, or remain outstanding (that is, addressed poorly) in the literature through 2020. Our searches resulted in the inclusion of 198 science products that at least partially addressed a Need identified in the Invasives topic. The Needs that were well and partially addressed included: studies of natural and anthropogenic factors influencing the distribution and spread; methods of preventing, eradicating and controlling invasive plant species; development of mapping techniques that provide regularly updated annual grass and fine fuel projections; and assessment of the efficacy of potential cheatgrass biocontrol agents. Needs that were addressed poorly included (1) investigations of livestock grazing as a tool for managing invasive plants and (2) investigations of cheatgrass die-offs and identification and subsequent study of potential biocontrol agents associated with those die-offs. The information provided in this assessment will assist updating the Plan along with other science strategies.

western United States↗

USGS2026

Coastal barrier resilience and resistance: Analysis and metrics for characterizing coastal state

Barrier islands are shaped by a variety of short- and long-term environmental processes such as storms and relative sea-level rise. These islands, found along the estuarine-marine interface, provide ecosystem services including storm surge and wave attenuation, erosion protection to inland marshes, habitat for fish and wildlife, and recreation. Natural resource managers require actionable information on how barrier island resilience and resistance changes over time to understand how an island’s current state relates to past conditions and to inform restoration prioritization and implementation. The U.S. Geological Survey and The Water Institute collaborated on a study to develop indicators of resilience and resistance for barrier islands in Louisiana. Here, resilience captures island persistence on yearly to decadal time scales, and resistance captures persistence on event time scales of days to weeks. The indicators fall in two categories: Tier 1 Screening Metrics, that can be readily calculated from available data, are easily interpretable as an evaluation of barrier condition, and provide a high-level snapshot of overall barrier resilience and resistance; and Tier 2 Analysis Metrics, which are detailed metrics that required specialized analysis and interpretation and are more applicable to answering specific questions managers may have about barrier state. The research team derived Tier 1 resilience indicators from subaerial land and vegetation cover calculated from publicly available maps and products based on satellite imagery. By benchmarking the total land and vegetation extent against their respective historical maxima, this metric provides a snapshot of an island’s current state in the context of its long-term trajectory. The research team developed Tier 1 resistance indicators based on subaerial island configuration and water level recurrence as a proxy for evaluating island resistance to storms, which are the primary driver of short-term change. These Tier 1 metrics can be analyzed over time to provide a high-level assessment of how an island’s resistance decreases because of elevation loss or sea-level rise or increases due to restoration or natural recovery. The research team developed Tier 2 resilience and resistance indicators and associated analyses to provide detailed information for specific time periods or applications (e.g., wildlife management). These metrics include habitat coverage from high-resolution maps, which show composition changes over time to capture the evolving resilience of specific habitat types; high tide flooding analysis, which evaluate island area relative to specified flooding thresholds to characterize resistance in the short-term or, if analyzed over time, indicate changes in resilience; and hypsometric curve analysis, which allows managers to evaluate island area changes above their own elevation benchmarks of interest and similarly characterize resistance in the short-term or indicate changes in resilience if assessed over time. The research team calculated Tier 1 metrics of the barrier islands and headlands along the coast of Louisiana for the period of 1984 through 2021 and Tier 2 metrics for select times during that period depending on data available and quality. The results were captured in a report card for each barrier, which also includes an overview of the metrics and their interpretation; a restoration and storm history; and Tier 1 and Tier 2 metric analysis, including benchmarking against coastwide and regional values as well as to an island’s pre-restoration trajectory. These report cards provide a readily digestible synthesis of barrier condition and trajectory that coastal managers can use to support restoration prioritization and other decisions.

Louisiana↗

USGS1985

Seismicity map of the State of Montana

This map is one of a series of seismicity maps produced by the U. S. Geological Survey that show earthquake data of individual states or groups of states at the scale of 1:1,000,000. This map shows only those earthquakes with epicenters located within the boundaries of Montana, even though earthquakes in bordering states or countries may have been felt or may have caused damage in Montana. The data in table 1 were used to compile the seismicity map; these data are a corrected, expanded, and updated (through 1981) version of the data used by Algermissen (1969) for a study of seismic risk in the United States. The locations and intensities of some earthquakes were revised and intensities were assigned where none had been before. Many earthquakes were added to the original list from new data sources as well as from some old data sources that had not been previously used. No earthquakes with magnitudes greater than 2.5 were located in Montana during 1981. The data in table 1 represent best estimates of the location of the epicenter, magnitude, and intensity of each earthquake on the basis of historical and current information. Some of the aftershocks from large earthquakes are listed, but not all, especially for earthquakes that occurred before seismic instruments were universally used. Special criteria used in compiling the list of earthquake in the State of Montana include the following: (1) All earthquakes with epicenters along the Montana-Wyoming border with a latitude of 45° N are listed in Montana. (2) Aftershocks of the 1925 and 1935 earthquakes were assigned the same geographic locations as the main shocks. (3) Instrumental epicenters for the 1959 Hebgen Lake earthquake and its aftershocks were 1ocated in Idaho, Montana, and Wyoming; only the ones located in Montana are included on this map. All non-instrumental locations were given the location of the main shock with an accuracy code that includes the community reporting the maximum intensity. The latitude and longitude coordinates of each epicenter were rounded to the nearest tenth of a degree and sorted so that all identical locations were grouped and counted. These locations are represented on the map by a triangle. The number of earthquakes at each location is shown on the map by the number to the right of the triangle. A Roman numeral to the left of a triangle is the maximum Modified Mercalli intensity (Wood and Neumann, 1931) of all earthquakes at that geographic location. The absence of an intensity value indicates that no intensities have been assigned to earthquakes at that location. The year shown below each triangle is the latest year for which the maximum intensity was recorded.

Montana↗

USGS2021

Middle and late Pleistocene pluvial history of Newark Valley, central Nevada, USA

Newark Valley lies between the two largest pluvial lake systems in the Great Basin, Lake Lahontan and Lake Bonneville. Soils and geomorphology, stratigraphic interpretations, radiocarbon ages, and amino acid racemization geochronology analyses were employed to interpret the relative and numerical ages of lacustrine deposits in the valley. The marine oxygen isotope stage (MIS) 2 beach barriers are characterized by well-preserved morphology and deposits with youthful soil development, with Bwk horizons and maximum stage I+ carbonate morphology. Radiocarbon ages of gastropods and tufas within these MIS 2–age deposits permit construction of a latest Pleistocene lake-level curve for Newark Valley, including a maximum limiting age of 13,780 ± 50 14 C yr B.P. for the most recent highstand, and they provide a calibration point for soil development in lacustrine deposits in the central Great Basin. The MIS 8–age to MIS 4–age beach barriers are higher in elevation and represent a larger lake than existed during MIS 2. The beach barriers have subdued morphology, are only preserved in short segments, and have stronger soil development, with Bkm and/or Bkmt horizons and maximum stage III+ to IV carbonate morphology. Newark Lake reached elevations higher than the MIS 2 highstand during at least two additional pluvial periods, MIS 16 and MIS 12, 10, or 8. These oldest lacustrine deposits do not have preserved shoreline features and are represented only by gravel lags, buried deposits, and buried soils with similar strong soil development. This sequence of middle and latest Pleistocene shorelines records a long-term pluvial history in this basin that remained internally drained for the last four or more pluvial cycles. Obtaining numerical ages from material within lacustrine deposits in the Great Basin can be challenging. Amino acid D/L values from gastropod shells and mollusk valves proved to be a valuable tool to correlate lacustrine deposits within Newark Valley. Comparison of soils and geomorphology results to independent 36 Cl cosmogenic nuclide ages from a different study indicated unexpected changes in rates of soil development during the past ~200,000 yr and suggested that common stratigraphic changes in lake stratigraphy could obscure incremental changes in soil development and/or complicate 36 Cl cosmogenic nuclide age estimates.

Nevada↗

USGS2023

Deep root activity overprints weathering of petrogenic organic carbon in shale

The oxidation of organic carbon in sedimentary bedrock (petrogenic OC, OC p e t r o "> petro ) is increasingly recognized as a potential source of CO 2 to the atmosphere. Recent studies provide evidence for the mobilization and oxidation of OC p e t r o "> petro in sedimentary bedrock during rock weathering. However, the mechanisms and rates remain uncertain, particularly where overlying soils and vegetation drive contemporaneous oxidation of recently fixed organic carbon. Here, we quantify OC p e t r o "> petro weathering across a 16 m shale depth profile in a steep, rapidly eroding forested hillslope in the Northern California Coast Ranges. We report solid and gas phase radiocarbon and stable isotope analyses of samples extracted from specialized in-situ samplers, and a supporting laboratory incubation experiment of the shale regolith. OC p e t r o "> petro is removed from the weathered bedrock at a rate of approximately 0.12 gC/m 3 yr, which is orders of magnitude lower than the rate of OC p e t r o "> petro oxidation we achieved in the laboratory with crushed samples (557.1 gC/m 3 /yr). This disparity occurs despite high O 2 ( g ) "> 2(g) content across the depth profile, indicating that physical accessibility of OC p e t r o "> petro can regulate oxidative weathering. There is no direct radiocarbon evidence of OC p e t r o "> petro oxidation in CO 2 ( g ) "> 2(g) across the upper 13 m of the weathering profile during both wet and dry seasons. Instead, vadose zone CO 2 ( g ) "> 2(g) production at the site is dominated by respiration of recently fixed carbon associated with deep rooting. OC p e t r o "> petro is clearly mobilized across the vadose zone during weathering in this rapidly eroding, oxygen-rich, biologically dynamic hillslope, but at rates far below what can be measured given the contribution of root-derived CO 2 ( g ) "> 2(g) .

California↗

USGS2017

Plant diversity increases with the strength of negative density dependence at the global scale

Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.

Science↗

USGS2022

The Geodetic Centroid (gCent) Catalog: Global earthquake monitoring with satellite imaging geodesy

Remote sensing geodetic observations (Interferometric Synthetic Aperture Radar [InSAR] and optical correlation [“pixel tracking”]) serve an increasingly diverse and important role in earthquake monitoring and response. This study introduces the Geodetic Centroid (gCent) catalog—an earthquake catalog derived solely from space‐based geodetic observations—and analysis of 74 earthquakes ( ⁠ M W 4.3–7.4) imaged from 1 August 2019 to 01 February 2022. For gCent, we use InSAR and optical correlation observations derived from the Sentinel‐1 satellites and various publicly available optical satellites to systematically image all global earthquakes M W 5.5 or larger and shallower than 25 km, M W 7.0 or larger at any depth, and other high‐impact earthquakes or seismic events of special interest. We invert surface displacements from successfully imaged earthquakes for the location, orientation, and dimensions of a single slipping fault patch that describes the centroid characteristics of the earthquake. These centroid models, in turn, are compiled into a catalog and used in U.S. Geological Survey/Advanced National Seismic System (ANSS) operational earthquake response products such as ShakeMaps and finite‐fault models. We provide a comparison of the gCent catalog to the ANSS Comprehensive Catalog and Global Centroid Moment Tensor (Global CMT) catalog to compare reported locations, depths, and magnitudes. We find that global earthquake catalogs not only generally provide reasonably comparable locations (within 10 km on average), but also they systematically overestimate depth that may have implications for earthquake shaking predictions based solely on earthquake origin information. Geodetic magnitudes are comparable to seismically inferred magnitudes, indicating that gCent models are unlikely to be systematically biased by the presence of postseismic deformation. We additionally highlight limitations of the gCent catalog induced by both the limitations of remote sensing imaging of earthquakes and our imposition of a simplified earthquake source description that does not include spatially distributed slip.

Bulletin of the Seismological Society of America↗

USGS2009

A review of plague persistence with special emphasis on fleas

Sylvatic plague is highly prevalent during infrequent epizootics that ravage the landscape of western North America. During these periods, plague dissemination is very efficient. Epizootics end when rodent and flea populations are decimated and vectored transmission declines. A second phase (enzootic plague) ensues when plague is difficult to detect from fleas, hosts or the environment, and presents less of a threat to public health. Recently, researchers have hypothesized that the bacterium (Yersinia pestis) responsible for plague maintains a continuous state of high virulence and thus only changes in transmission efficiency explain the shift between alternating enzootic and epizootic phases. However, if virulent transmission becomes too inefficient, strong selection might favor an alternate survival strategy. Another plausible non-exclusive hypothesis, best supported from Asian field studies, is that Y. pestis persists (locally) at foci by maintaining a more benign relationship within adapted rodents during the long expanses of time between outbreaks. From this vantage, it can revert to the epizootic (transmission efficient) form. Similarly, in the United States (US), enzootic plague persistence has been proposed to develop sequestered within New World rodent carriers. However, the absence of clear support for rodent carriers in North America has encouraged a broader search for alternative explanations. A telluric plague existence has been proposed. However, the availability of flea life stages and their hosts could critically supplement environmental plague sources, or fleas might directly represent a lowlevel plague reservoir. Here, we note a potentially pivotal role for fleas. These epizootic plague vectors should be closely studied with newer more exacting methods to determine their potential to serve as participants in or accomplices to a plague persistence reservoir.

Journal of Vector Borne Diseases↗

USGS2011

Proceedings of the 2011 Elwha River Science Symposium

After years of anticipation, volumes of Environmental Impact Statements, multiple mitigation projects, and the multidisciplinary collection of predam removal data, the deconstruction phase of the Elwha River restoration officially began on September 17th, 2011. With their simultaneous decommissioning, the removal of the 64 m tall Glines Canyon Dam and the 33 m tall Elwha Dam represents one of the largest such projects of its kind in North America. It’s also an excellent opportunity to study large-scale ecosystem restoration, as the majority of the reconnected habitat that will become available to recolonizing salmon occurs in the protected wilderness areas of Olympic National Park. As part of a week-long series of ‘Celebrate Elwha’ events, which culminated with a moving ceremony commemorating the official launch of dam removal, I was proud to work with a number of dedicated people, listed below, to organize the two day 2011 Elwha River Science Symposium. Many of the scientists working on the Elwha project have regularly met, since around 2004, for annual meetings. Loosely organized under the auspices of the Elwha Research and Elwha Nearshore consortia, the annual meetings have been informative for many reasons, including the sharing of study plans, field schedules, and preliminary results. It has been a great way for groups of physical scientists and groups of biologists to learn about the questions of interest to each group and to explore areas of overlap. In some cases, these meetings have spawned new collaborations, synergies, and research directions. In planning for the 2011 Elwha River Science Symposium, we sought to retain this espirit de corps, but realized that the start of dam removal heralded an important new phase of the project and called for an event that celebrated this special occasion.

Washington↗

USGS1997

The modern atmospheric background dust load: Recognition in Central Asian snowpack, and compositional constraints

Dusts in strata of snowpack in the Alai-Pamir range, Kirghizstan, Central Asia, have chemical compositions that are in the same restricted range as those of the dusts found in snowpacks at three other locations: central south Greenland, the St. Elias range (Alaska), and coastal Antarctica, where special-type local dust sources certainly cannot dominate. This similarity at the four widely separated sites appears to indicate that there is a modern atmospheric background dust that is the same on a regional, hemispheric, or global scale. The common compositional range is that of average crustal rock, or of moderately ferromagnesian volcanic rock. It is not that of carbonate, nor highly siliciceous rocks. Previously, the existence of an atmospheric background dust has been postulated only on the basis of its particle size distribution, and only from observations in polar regions. The present study partially determines the chemical composition of the background dust, and confirms its existence in snowpack at four localities worldwide, including the center of the earth's largest continent where dusts of local source have considerable influence.

Geophysical Research Letters↗

USGS2005

Liquefaction induced by historic and prehistoric earthquakes in western Puerto Rico

Dozens of liquefaction features in western Puerto Rico probably formed during at least three large earthquakes since A.D. 1300. Many of the features formed during the 1918 moment magnitude (M) 7.3 event and the 1670 event, which may have been as large as M 7 and centered in the Añasco River Valley. Liquefaction features along Río Culebrinas, and possibly a few along Río Grande de Añasco, appear to have formed ca. A.D. 1300–1508 as the result of a M ≥ 6.5 earthquake. We conducted reconnaissance along Río Culebrinas, Río Grande de Añasco, and Río Guanajibo, where we found and studied numerous liquefaction features, dated organic samples occurring in association with liquefaction features, and performed liquefaction potential analysis with geotechnical data previously collected along the three rivers. Our ongoing study will provide additional information regarding the age and size distribution of liquefaction features along the western, northern, and eastern coasts and will help to improve estimates of the timing, source areas, and magnitudes of earthquakes that struck Puerto Rico during the late Holocene.

Añasco River Valley, Río Culebrinas, Río Grande de↗

USGS1974

Significance of lead residues in mallard tissues

Tissues of adult, lead-dosed mallards that either died or were sacrificed were analyzed for lead. Lead levels in brains, tibiae, and breast muscle of ducks that died and in tibiae of ducks that were sacrificed increased significantly from dosage until death. Lead in the heart, lung, and blood from sacrificed ducks decreased significantly from dosage until death. Lead concentrations in tissues from ducks in the two groups were not significantly different except for the liver, kidney, and lung. Average lead levels in the livers and kidneys of ducks that died were significantly higher than those in ducks that were sacrificed. The mean concentration of lead in the lungs of the ducks sacrificed was significantly higher than the mean level in the lungs of ducks that died. Measurements of the lead concentrations in this study, when compared with lead levels reported in the literature for avian and non-avian species, showed that arbitrary diagnostic levels indicating lead poisoning could be set. In mallard ducks, lead levels exceeding 3 ppm in the brain, 6 to 20 ppm in the kidney or liver, or 10 ppm in clotted blood from the heart indicated acute exposure to lead.

Special Scientific Report - Wildlife↗

USGS2011

Redox chemistry and natural organic matter (NOM): Geochemists' dream, analytical chemists' nightmare

Natural organic matter (NOM) is an inherently complex mixture of polyfunctional organic molecules. Because of their universality and chemical reversibility, oxidation/reductions (redox) reactions of NOM have an especially interesting and important role in geochemistry. Variabilities in NOM composition and chemistry make studies of its redox chemistry particularly challenging, and details of NOM-mediated redox reactions are only partially understood. This is in large part due to the analytical difficulties associated with NOM characterization and the wide range of reagents and experimental systems used to study NOM redox reactions. This chapter provides a summary of the ongoing efforts to provide a coherent comprehension of aqueous redox chemistry involving NOM and of techniques for chemical characterization of NOM. It also describes some attempts to confirm the roles of different structural moieties in redox reactions. In addition, we discuss some of the operational parameters used to describe NOM redox capacities and redox states, and describe nomenclature of NOM redox chemistry. Several relatively facile experimental methods applicable to predictions of the NOM redox activity and redox states of NOM samples are discussed, with special attention to the proposed use of fluorescence spectroscopy to predict relevant redox characteristics of NOM samples.

ACS Symposium Series↗

USGS2021

A common garden super-experiment: An impossible dream to inspire possible synthesis

Global change threatens plant diversity and disrupts its interrelationship with ecosystem structure and function. This disruption in turn undermines confidence in the knowledge ecologists produce, and whether it will translate into multidisciplinary research settings or guide the effective management of natural lands. To address this challenge, ecology needs to consider the interactions between different levels of biological hierarchy, especially how they feedback on, and are mediated by, plant diversity. Doing so will require conducting empirical work and developing theory that simultaneously considers multiple disciplinary perspectives and units of study. Here we advocate the use of common gardens to integrate ecology, evolutionary biology, and ecosystem science through an explicit focus on simultaneous measurement of response variables at multiple levels of biological organization. This approach will provide opportunities to evaluate assumptions important to prediction, such as space-for-time substitution, and tackle the integration of physicochemical and eco-evolutionary foundations to understanding plants and ecosystems. Synthesis: We summarize the large body of research on Sonoran Desert winter annuals to demonstrate how experimental designs that employ common gardens to integrate processes across scales hold special promise. This includes refining trait-based theories of plant strategies, providing insight into ecosystem responses to global change, and collaborating effectively with other scientific disciplines.

Journal of Ecology↗

USGS2016

Preface: Impacts of extreme climate events and disturbances on carbon dynamics

The impacts of extreme climate events and disturbances (ECE&D) on the carbon cycle have received growing attention in recent years. This special issue showcases a collection of recent advances in understanding the impacts of ECE&D on carbon cycling. Notable advances include quantifying how harvesting activities impact forest structure, carbon pool dynamics, and recovery processes; observed drastic increases of the concentrations of dissolved organic carbon and dissolved methane in thermokarst lakes in western Siberia during a summer warming event; disentangling the roles of herbivores and fire on forest carbon dioxide flux; direct and indirect impacts of fire on the global carbon balance; and improved atmospheric inversion of regional carbon sources and sinks by incorporating disturbances. Combined, studies herein indicate several major research needs. First, disturbances and extreme events can interact with one another, and it is important to understand their overall impacts and also disentangle their effects on the carbon cycle. Second, current ecosystem models are not skillful enough to correctly simulate the underlying processes and impacts of ECE&D (e.g., tree mortality and carbon consequences). Third, benchmark data characterizing the timing, location, type, and magnitude of disturbances must be systematically created to improve our ability to quantify carbon dynamics over large areas. Finally, improving the representation of ECE&D in regional climate/earth system models and accounting for the resulting feedbacks to climate are essential for understanding the interactions between climate and ecosystem dynamics.

Biogeosciences↗

USGS2021

Efficacy of manipulating reproduction of common ravens to conserve sensitive prey species: Three case studies

Expansion of human enterprise across western North America has resulted in an increase in availability of anthropogenic resource subsidies for generalist species. This has led to increases in generalists’ population numbers across landscapes that were previously less suitable for their current demographic rates. Of particular concern are growing populations of common ravens ( Corvus corax ; ravens), because predation by ravens is linked to population declines of sensitive species. Ecosystem managers seek management options for mitigating the adverse effects of raven predation where unsustainable predator–prey conflicts exist. We present 3 case studies examining how manipulating reproductive success of ravens influences demographic rates of 2 sensitive prey species. Two case studies examine impacts of removing raven nests or oiling raven eggs on nest survival of greater sage-grouse ( Centrocercus urophasianus ; sage-grouse) within Wyoming and the Great Basin of California and Nevada, USA, respectively. The third case study uses Mojave desert tortoise ( Gopherus agassizii ; tortoise) decoys to examine effects of oiling raven eggs on depredation rates of juvenile tortoises in the Mojave Desert in California. Initial trial years from all 3 case studies were consistent in finding improved vital rates associated with the application of strategies for reducing reproductive success of ravens. Specifically, removal of raven nests resulted in increased nest survival of sage-grouse within treatment areas where predation by ravens was the primary cause of nest failure. In addition, nest survival of sage-grouse and survival of juvenile tortoise decoys was higher following a treatment of oiling the eggs of ravens in their nests at 2 sites within the Great Basin and 4 tortoise conservation areas in the Mojave Desert in California. Along with specialized technologies that can make techniques such as egg-oiling more feasible, these findings support these management practices as important tools for managing ravens, especially in areas where breeding ravens have negative impacts on sensitive prey species.

California, Nevada, Wyoming↗

USGS2006

Wildlife and habitat damage assessment from Hurricane Charley: Recommendations for recovery of the J. N. "Ding" Darling National Wildlife Refuge Complex

• On 13 August 2004, the first of four hurricanes to strike Florida in <6 weeks came ashore near J. N. “Ding” Darling National Wildlife Refuge (JNDDNWR) Complex, Sanibel Island, Florida. The eye of Category 4 Hurricane Charley passed just north of Sanibel Island with maximum sustained winds of 145 mph (123 knots) and a storm surge of 0.3-2.7 m (1-9 ft). Three USGS-BRD scientists (coastal ecologist and research wildlife biologists) and a USFWS wildlife biologist surveyed the storm damage to JNDDNWR Complex on the ground from 20-24 September 2004. • At the request of United States Fish and Wildlife Service refuge staff, the USGS team concentrated on assessing damage to wetlands and habitat for selected bird populations (especially mangrove forests, Mangrove Cuckoos [Coccyzus minor], and Black-whiskered Vireo [Vireo altiloquus]), waterbird rookeries (mangrove islands), impoundments (waterbirds and waterfowl), sea grass beds (manatees), and upland hardwood hammocks and ridges (threatened eastern indigo snake [Drymarchon couperi]). • The refuge complex sustained moderate to catastrophic damage to vegetation, especially mangrove forests and waterbird nesting or roosting islands. Lumpkin Island, Hemp Island, and Bird Key waterbird nesting areas had >50% and sometimes 90% of their vegetation severely damaged (dead, broken tree stems, and tipped trees). The Shell Mound Trail area of JNDDNWR sustained catastrophic damage to its old growth mangrove forests. Direct storm mortality and injury to manatees in the area of the JNDDNWR Complex was probably slight as manatees may have several strategies to reduce storm mortality. Damage to seagrass beds, an important habitat for manatees, fishes and invertebrates, is believed to be limited to the breach at North Captiva Island. At this breach, refuge staff documented inundation of beds by sand and scarring by trees dragged by winds. • Because seagrass beads and manatee habitat extend beyond refuge boundaries (see p. 28), a regional approach with partner agencies to more thoroughly assess storm impacts and monitor recovery of seagrass and manatees is recommended. • Besides intensive monitoring of waterbirds and their nesting habitat (pre- and post-storm), the survey team recommends that the Mangrove Cuckoo be used as an indicator species for recovery of mangrove forests and also for monitoring songbirds at risk (this songbird is habitat-area sensitive). Black-whiskered Vireo may be another potential indicator species to monitor in mangrove forests. Monitoring for these species can be done by distance sampling on transects or by species presenceabsence from point counts. • Damaged vegetation should be monitored for recovery (permanent or long-term plots), especially where previous study plots have been established and with additional plots in mangrove forests of waterbird nesting islands and freshwater wetlands. • Potential loss of wetlands (and information for management) may be prevented by water level monitoring (3 permanent stations), locating the positions (GPS-GIS) and maintaining existing water control structures, creating a GIS map of the refuge with accurate vertical data, and monitoring and eradicating invasive plants. Invasive species, including Brazilian pepper (Schinus terebinthifolius) and air potato (Dioscorea bulbifora), were common in a very limited survey and may become more dominant in areas damaged by the storm. Special attention is needed to eradicate these exotic plants. • As an important monitoring goal, the survey team recommends that species presence-absence data analysis (with probability of detection) be used to determine changes in animal communities. This could be accomplished possibly with comparison to other storm-damaged and undamaged refuges in the Region. This information may be helpful to refuge managers when storms return in the future.

Florida↗

USGS2000

Rising seas and sinking coastal marshes: Implications to Atlantic waterbirds

Along the mid-Atlantic U.S. coast, relative sea level rise (RSLR) is higher than the global average of 1.5-2.0 mm/yr, ranging from about 2.5 in parts of Virginia and Delaware to about 4.0 in New Jersey (Atlantic City and Sandy Hook) and near the mouth of Chesapeake Bay, Virginia. Very few data exist on marsh elevation changes, but information from some areas in Virginia, New Jersey and New York suggest that marsh islands are not 'keeping pace' with this RSLR. We began a study in 1999 that addresses changes in sea level and marsh elevation at sites from Cape Cod to s. Virginia known to be important areas for migratory waterbirds, including waterfowl, shorebirds, wading birds, and seabirds. Marsh monitoring sites have been established and data on microhabitat use by birds during all 4 seasons is being collected at these sites. Species expected to be most vulnerable to RSLR in these marshes are breeding species such as Laughing Gulls, Common, Gull-billed and Forster's terns, Clapper Rails, and American Black Ducks. Most of these species are of special concern at state, regional, or national levels. We show how important this region to these species from a flyway perspective, with> 70% of all Atlantic coast Laughing Gulls and Forster's Terns nesting from New Jersey to Virginia.

Book chapter↗