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Articles 601 - 630 of 918
Full-Text Articles in Geology
Sorta Situ: The New Reality Of Management Conditions For Wildlife Populations In The Absence Of "Wild" Spaces, Barbara A. Wolfe, Roberto F. Aguilar, A. Alonso Aguirre, Glenn H. Olsen, Evan S. Blumer
Sorta Situ: The New Reality Of Management Conditions For Wildlife Populations In The Absence Of "Wild" Spaces, Barbara A. Wolfe, Roberto F. Aguilar, A. Alonso Aguirre, Glenn H. Olsen, Evan S. Blumer
United States Geological Survey: Staff Publications
The rate of species loss today is approaching catastrophic levels. Scientists project that over the next two decades, more than 1 million species of plants and animals will become extinct. E.O. Wilson has estimated that "the rate ofloss may exceed 50,000 a year, 137 a day ... this rate, while horrendous, is actually the minimal estimate, based on the species/area relationship alone" (Kellert and Wilson 1993, p. 16; Aguirre 2009). Ever-expanding communities, strained natural resources, changes in land use, and other anthropogenic drivers are compromising ecosystems and rapidly changing the landscape and the availability of "wild" spaces.
Agricultural Drought Monitoring In Kenya Using Evapotranspiration Derived From Remote Sensing And Reanalysis Data, Michael T. Marshall, Christopher Funk, Joel Michaelsen
Agricultural Drought Monitoring In Kenya Using Evapotranspiration Derived From Remote Sensing And Reanalysis Data, Michael T. Marshall, Christopher Funk, Joel Michaelsen
United States Geological Survey: Staff Publications
More than half of the people in sub-Saharan Africa live on less than US$ 1.25 per day, and nearly 30% do not receive sufficient nourishment to maintain daily health (UN, 2009a). These figures are expected to rise as a result of the recent global financial crisis that has led to an increase in food prices. Food for Peace (FFP), the program that administers more than 85% of U.S. international food aid, recently reported that the seven largest recipient countries of food aid worldwide are in sub-Saharan Africa (FFP, 2010). In Kenya, the fifth largest recipient of food aid from FFP …
Hurricane Disturbance And Recovery Of Energy Balance, Co2 Fluxes And Canopy Structure In A Mangrove Forest Of The Florida Everglades, Jordan G. Barr, Vic Engel, Thomas J. Smith, José D. Fuentes
Hurricane Disturbance And Recovery Of Energy Balance, Co2 Fluxes And Canopy Structure In A Mangrove Forest Of The Florida Everglades, Jordan G. Barr, Vic Engel, Thomas J. Smith, José D. Fuentes
United States Geological Survey: Staff Publications
Eddy covariance (EC) estimates of carbon dioxide (CO2) fluxes and energy balance are examined to investigate the functional responses of a mature mangrove forest to a disturbance generated by Hurricane Wilma on October 24, 2005 in the Florida Everglades. At the EC site, high winds from the hurricane caused nearly 100% defoliation in the upper canopy and widespread tree mortality. Soil temperatures down to −50 cm increased, and air temperature lapse rates within the forest canopy switched from statically stable to statically unstable conditions following the disturbance. Unstable conditions allowed more efficient transport of water vapor and CO2 from …
Assessment Of Coal Geology, Resources, And Reserves In The Montana Powder River Basin, Jon E. Haacke, David C. Scott, Lee M. Osmonson, James A. Luppens, Paul E. Pierce, Jay A. Gunderson
Assessment Of Coal Geology, Resources, And Reserves In The Montana Powder River Basin, Jon E. Haacke, David C. Scott, Lee M. Osmonson, James A. Luppens, Paul E. Pierce, Jay A. Gunderson
United States Geological Survey: Publications
The purpose of this report is to summarize geology, coal resources, and coal reserves in the Montana Powder River Basin (MTPRB) assessment area in southeastern Montana. This report represents the fourth assessment area within the Powder River Basin to be evaluated in the continuing U.S. Geological Survey regional coal assessment program.
There are four active coal mines in the MTPRB assessment area: the Spring Creek and Decker Mines, both near Decker; the Rosebud Mine, near Colstrip; and the Absaloka Mine, west of Colstrip. During 2011, coal production from these four mines totaled approximately 36 million short tons (MST). A fifth …
Copper Pellets Simulating Oral Exposure To Copper Ammunition: Absence Of Toxicity In American Kestrels (Falco Sparverius), J. Christian Franson, Lesanna L. Lahner, Carol U. Meteyer, Barnett A. Rattner
Copper Pellets Simulating Oral Exposure To Copper Ammunition: Absence Of Toxicity In American Kestrels (Falco Sparverius), J. Christian Franson, Lesanna L. Lahner, Carol U. Meteyer, Barnett A. Rattner
United States Geological Survey: Staff Publications
To evaluate the potential toxicity of copper
(Cu) in raptors that may consume Cu bullets, shotgun
pellets containing Cu, or Cu fragments as they feed on
wildlife carcasses, we studied the effects of metallic Cu
exposure in a surrogate, the American kestrel (Falco
sparverius). Sixteen kestrels were orally administered
5 mg Cu/g body mass in the form of Cu pellets
(1.18–2.00 mm in diameter) nine times during 38 days and
10 controls were sham gavaged on the same schedule. With
one exception, all birds retained the pellets for at least 1 h,
but most (69%) regurgitated pellets during …
Mapping Recent Decadal Climate Variations In Precipitation And Temperature Across Eastern Africa And The Sahel, Christopher Funk, Joel Michaelsen, Michael T. Marshall
Mapping Recent Decadal Climate Variations In Precipitation And Temperature Across Eastern Africa And The Sahel, Christopher Funk, Joel Michaelsen, Michael T. Marshall
United States Geological Survey: Staff Publications
This chapter presents a novel interpolation approach that combines long-term mean satellite observations, station data, and topographic fields to produce grids of climate normals and trends. The approach was developed by the Climate Hazard Group (CHG) at the University of California, Santa Barbara (UCSB), to support food security analyses for the U.S. Agency for International Development’s (USAID) Famine Early Warning Systems Network (FEWS NET). The resulting FEWS NET Climatology (FCLIM) combines moving window regressions (MWRs) with geostatistical interpolation (kriging). Satellite and topographic fields often exhibit strong local correlations with in situ measurements of air temperature and rainfall. The FCLIM method …
Gene Transcription In Sea Otters (Enhydra Lutris); Development Of A Diagnostic Tool For Sea Otter And Ecosystem Health, Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William Van Bonn, Lance Adams, James L. Bodkin, Brenda Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott
Gene Transcription In Sea Otters (Enhydra Lutris); Development Of A Diagnostic Tool For Sea Otter And Ecosystem Health, Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William Van Bonn, Lance Adams, James L. Bodkin, Brenda Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott
United States Geological Survey: Staff Publications
Gene transcription analysis for diagnosing or monitoring wildlife health requires the ability to distinguish pathophysiological change from natural variation. Herein, we describe methodology for the development of quantitative real-time polymerase chain reaction (qPCR) assays to measure differential transcript levels of multiple immune function genes in the sea otter (Enhydra lutris); sea otter-specific qPCR primer sequences for the genes of interest are defined. We establish a ‘reference’ range of transcripts for each gene in a group of clinically healthy captive and free-ranging sea otters. The 10 genes of interest represent multiple physiological systems that play a role in immuno-modulation, …
Do Bioclimate Variables Improve Performance Of Climate Envelope Models?, James I. Watling, Stephanie S. Romanach, David N. Bucklin, Carolina Speroterra, Laura A. Brandt, Leonard G. Pearlstine, Frank J. Mazzotti
Do Bioclimate Variables Improve Performance Of Climate Envelope Models?, James I. Watling, Stephanie S. Romanach, David N. Bucklin, Carolina Speroterra, Laura A. Brandt, Leonard G. Pearlstine, Frank J. Mazzotti
United States Geological Survey: Staff Publications
Climate envelope models are widely used to forecast potential effects of climate change on species distributions. A key issue in climate envelope modeling is the selection of predictor variables that most directly influence species. To determine whether model performance and spatial predictions were related to the selection of predictor variables, we compared models using bioclimate variables with models constructed from monthly climate data for twelve terrestrial vertebrate species in the southeastern USA using two different algorithms (random forests or generalized linear models), and two model selection techniques (using uncorrelated predictors or a subset of user-defined biologically relevant predictor variables). There …
Global Air Temperature Variability Independent Of Sea-Surface Temperature Influences, Andrew C. Comrie, Gregory J. Mccabe
Global Air Temperature Variability Independent Of Sea-Surface Temperature Influences, Andrew C. Comrie, Gregory J. Mccabe
United States Geological Survey: Staff Publications
Mean global surface air temperature (SAT) and sea surface temperature (SST) display substantial variability on timescales ranging from annual to multi-decadal. We review the key recent literature on connections between global SAT and SST variability. Although individual ocean influences on SAT have been recognized, the combined contributions of worldwide SST variability on the global SAT signal have not been clearly identified in observed data.Weanalyze these relations using principal components of detrended SST, and find that removing the underlying combined annual, decadal, and multi-decadal SST variability from the SAT time series reveals a nearly monotonic global warming trend in SAT since …
Gonadal Abnormalities In Frogs (Lithobates Spp.) Collected From Managed Wetlands In An Agricultural Region Of Nebraska, Usa, Diana M. Papoulias, Matt S. Schwarz, Lourdes Mena
Gonadal Abnormalities In Frogs (Lithobates Spp.) Collected From Managed Wetlands In An Agricultural Region Of Nebraska, Usa, Diana M. Papoulias, Matt S. Schwarz, Lourdes Mena
United States Geological Survey: Staff Publications
Nebraska’s Rainwater Basin (RWB) provides important wetland habitat for North American migratory birds. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Plains leopard (Lithobates blairi) metamorphs from RWB wetlands with varying concentrations of pesticides were evaluated for a suite of biomarkers of exposure to endocrine active chemicals. Froglets had ovarian dysgenesis, high rates of testicular oocytes, and female-biased sex ratios however, there was no clear statistical association between pesticide concentrations and biomarkers. Data interpretation was hindered because timing and duration …
History And Evaluation Of National-Scale Geochemical Data Sets For The United States, David B. Smith, Steven M. Smith, John D. Horton
History And Evaluation Of National-Scale Geochemical Data Sets For The United States, David B. Smith, Steven M. Smith, John D. Horton
United States Geological Survey: Staff Publications
Six national-scale, or near national-scale, geochemical data sets for soils or stream sediments exist for the United States. The earliest of these, here termed the ‘Shacklette’ data set, was generated by a U.S. Geological Survey (USGS) project conducted from 1961 to 1975. This project used soil collected from a depth of about 20 cm as the sampling medium at 1323 sites throughout the conterminous U.S. The National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance (NUREHSSR) Program of the U.S. Department of Energy was conducted from 1975 to 1984 and collected either stream sediments, lake sediments, or soils at more …
Remote Sensing Of Evapotranspiration For Operational Drought Monitoring Using Principles Of Water And Energy Balance, Gabriel B. Senay, Stefanie Bohms, James P. Verdin
Remote Sensing Of Evapotranspiration For Operational Drought Monitoring Using Principles Of Water And Energy Balance, Gabriel B. Senay, Stefanie Bohms, James P. Verdin
United States Geological Survey: Staff Publications
Evapotranspiration (ET) is an important component of the hydrologic budget because it reflects the exchange of mass and energy between the soil–water–vegetation system and the atmosphere. Prevailing weather conditions influence potential or reference ET through variables such as radiation, temperature, wind, and relativity humidity. In addition to these weather variables, actual ET (ETa) is also affected by land cover type and condition, as well as soil moisture. The dependence of ETa on land cover and soil moisture, and its direct relationship with carbon dioxide assimilation in plants, makes it an important variable for monitoring drought, crop yield, …
Development And Application Of Methods Used To Source Prehistoric Southwestern Maize: A Review, Larry Benson
Development And Application Of Methods Used To Source Prehistoric Southwestern Maize: A Review, Larry Benson
United States Geological Survey: Staff Publications
Archaeological cobs free of mineral contaminants should be used to source the soils in which they were grown. Mineral contaminants often contain much higher concentrations of metals than vegetal materials and can alter a cob’s apparent metal and heavy-isotope content. Cleaning a cob via immersion in an acid solution for more than a few minutes will result in the incongruent and sometimes complete leaching of metals, including strontium (Sr), from the cob. When using 87Sr/86Sr to determine the location of potential agriculture fields, it is best to either integrate several depth-integrated soil samples or to integrate several …
On Thinning Of Chains In Mcmc, William A. Link, Mitchell J. Eaton
On Thinning Of Chains In Mcmc, William A. Link, Mitchell J. Eaton
United States Geological Survey: Staff Publications
1. Markov chain Monte Carlo (MCMC) is a simulation technique that has revolutionised the analysis of ecological data, allowing the fitting of complex models in a Bayesian framework. Since 2001, there have been nearly 200 papers using MCMC in publications of the Ecological Society of America and the British Ecological Society, including more than 75 in the journal Ecology and 35 in the Journal of Applied Ecology.
2. We have noted that many authors routinely ‘thin’ their simulations, discarding all but every kth sampled value; of the studies we surveyed with details on MCMC implementation, 40% reported thinning.
3. Thinning …
Spatially Explicit Models For Inference About Density In Unmarked Or Partially Marked Populations, Richard B. Chandler, J. Andrew Royle
Spatially Explicit Models For Inference About Density In Unmarked Or Partially Marked Populations, Richard B. Chandler, J. Andrew Royle
United States Geological Survey: Staff Publications
Recently developed spatial capture-recapture (SCR) models represent a major advance over traditional capture-recapture (CR) models because they yield explicit estimates of animal density instead of population size within an unknown area. Futhermore, unlike nonspatial CR methods, SCR models account for heterogeneity in capture probability arising from the juxtaposition of animal activity centers and sample locations. Although the utility of SCR methods is gaining recognition, the requirement that all individuals can be uniquely identified exludes their use in many contexts. In this paper, we develop models for situations in which individual recognition is not possible, thereby allowing SCR concepts to be …
On Thinning Of Chains In Mcmc, William A. Link, Mitchell J. Eaton
On Thinning Of Chains In Mcmc, William A. Link, Mitchell J. Eaton
United States Geological Survey: Staff Publications
1. Markov chain Monte Carlo (MCMC) is a simulation technique that has revolutionised the analysis of ecological data, allowing the fitting of complex models in a Bayesian framework. Since 2001, there have been nearly 200 papers using MCMC in publications of the Ecological Society of America and the British Ecological Society, including more than 75 in the journal Ecology and 35 in the Journal of Applied Ecology.
2. We have noted that many authors routinely ‘thin’ their simulations, discarding all but every kth sampled value; of the studies we surveyed with details on MCMC implementation, 40% reported thinning.
3. Thinning …
Sea-Level History During The Last Interglacial Complex On San Nicolas Island, California: Implications For Glacial Isostatic Adjustment Processes, Paleozoogeography And Tectonics, Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Lindsey T. Groves, Jerry X. Mitrovica, Deanna Laurel
Sea-Level History During The Last Interglacial Complex On San Nicolas Island, California: Implications For Glacial Isostatic Adjustment Processes, Paleozoogeography And Tectonics, Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Lindsey T. Groves, Jerry X. Mitrovica, Deanna Laurel
United States Geological Survey: Staff Publications
San Nicolas Island, California has one of the best records of fossiliferous Quaternary marine terraces in North America, with at least fourteen terraces rising to an elevation of ~270 m above present-day sea level. In our studies of the lowest terraces, we identified platforms at 38–36 m (terrace 2a), 33–28 m (terrace 2b), and 13–8 m (terrace 1). Uranium-series dating of solitary corals from these terraces yields three clusters of ages: ~120 ka on terrace 2a (marine isotope stage [MIS] 5.5), ~120 and ~100 ka on terrace 2b (MIS 5.5 and 5.3), and ~80 ka (MIS 5.1) on terrace 1.We …
Tectonic Influences On The Preservation Of Marine Terraces: Old And New Evidence From Santa Catalina Island, California, R. Randall Schumann, Scott A. Minor, Daniel R. Muhs, Lindsey T. Groves, John P. Mcgeehan
Tectonic Influences On The Preservation Of Marine Terraces: Old And New Evidence From Santa Catalina Island, California, R. Randall Schumann, Scott A. Minor, Daniel R. Muhs, Lindsey T. Groves, John P. Mcgeehan
United States Geological Survey: Staff Publications
The California Channel Islands contain some of the best geologic records of past climate and sea-level changes, recorded in uplifted, fossil-bearing marine terrace deposits. Among the eight California Channel Islands and the nearby Palos Verdes Hills, only Santa Catalina Island does not exhibit prominent emergent marine terraces, though the same terrace-forming processes that acted on the other Channel Islands must also have occurred on Santa Catalina. We re-evaluated previous researchers' field evidence and examined new topographic, bathymetric, and stream-profile data in order to find possible explanations for the lack of obvious marine terrace landforms or deposits on the island today. …
Spring Migration Of Mallards From Arkansas As Determined By Satellite Telemetry, David George Krementz, Kwasi Asante, Luke W. Naylor
Spring Migration Of Mallards From Arkansas As Determined By Satellite Telemetry, David George Krementz, Kwasi Asante, Luke W. Naylor
United States Geological Survey: Staff Publications
We used satellite telemetry to document spring migration phenology, routes, stopover regions, and nesting sites of mallards Anas platyrhynchos marked in Arkansas during the winters of 2004–2007. Of the 143 marked mallards that migrated from Arkansas, they did so, on average, by mid-March. Mallards flew over the Missouri Ozarks and 42% made an initial stopover in Missouri, where they used areas that had larger rivers (Mississippi River, Missouri River) embedded in an agricultural landscape. From this stopover region they either migrated directly to the Prairie Pothole Region (PPR) or they migrated north to Minnesota where they either moved next to …
Geogram 2011, David J. Keeling Editor, Wku Department Of Geography And Geology
Geogram 2011, David J. Keeling Editor, Wku Department Of Geography And Geology
Earth, Environmental, and Atmospheric Sciences Publications
No abstract provided.
Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa
Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa
Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research
Human activities such as conversion of natural ecosystem to croplands and urban-centers, deforestation and afforestation impact biophysical properties of land surface such as albedo, energy balance, and surface roughness. Alterations in these properties affect the heat and moisture exchanges between the land surface and atmospheric boundary layer. The objectives of this research were; (i) to quantitatively identify the High plains’ regional climate change in temperatures over the period 1895 to 2006, (ii) detect the signatures of anthropogenic forcing of LULC changes on the regional climate change of the High Plains, and (iii) examine the trends in evolving regional latent heat …
Full Conference Program With Abstracts, Jason S. Polk, Leslie A. North
Full Conference Program With Abstracts, Jason S. Polk, Leslie A. North
International 2011 Conference on Karst Hydrogeology and Ecosystems
No abstract provided.
Secretive Marsh Bird Species Co-Occurrences And Habitat Associations Across The Midwest, Usa, Jason R. Bolenbaugh, Sarah E. Lehnen, David G. Krementz
Secretive Marsh Bird Species Co-Occurrences And Habitat Associations Across The Midwest, Usa, Jason R. Bolenbaugh, Sarah E. Lehnen, David G. Krementz
United States Geological Survey: Staff Publications
Because secretive marsh birds are difficult to detect, population status and habitat use for these birds are not well known. We conducted repeated surveys for secretive marsh birds across 264 sites in the Upper Mississippi River and Great Lakes Joint Venture region to estimate abundance, occupancy, and detection probabilities during the 2008 and 2009 breeding seasons. We identified species groups based on observed species co-occurrences. Two species, least bittern Ixobrychus exilis and American bittern Botaurus lentiginosus, co-occurred with other species less often than expected by chance, and two species groups, rails (Virginia rail Rallus limicola and sora Porzana carolina) and …
Rapid Wetland Expansion During European Settlement And Its Implication For Marsh Survival Under Modern Sediment Delivery Rates, Matthew L. Kirwan, A. Brad Murray, Jeffrey P. Donnelly, D. Reide Corbett
Rapid Wetland Expansion During European Settlement And Its Implication For Marsh Survival Under Modern Sediment Delivery Rates, Matthew L. Kirwan, A. Brad Murray, Jeffrey P. Donnelly, D. Reide Corbett
United States Geological Survey: Staff Publications
Fluctuations in sea-level rise rates are thought to dominate the formation and evolution of coastal wetlands. Here we demonstrate a contrasting scenario in which land-use–related changes in sediment delivery rates drive the formation of expansive marshland, and vegetation feedbacks maintain their morphology despite recent sediment supply reduction. Stratigraphic analysis and radiocarbon dating in the Plum Island Estuary (Massachusetts, United States) suggest that salt marshes expanded rapidly during the eighteenth and nineteenth centuries due to increased rates of sediment delivery following deforestation associated with European settlement. Numerical modeling coupled with the stratigraphic observations suggests that existing marshland could survive, but not …
Effects Of Rodent Species, Seed Species, And Predator Cues On Seed Fate, Kelly J. Sivy, Steven M. Ostoja, Eugene W. Schupp, Susan Durham
Effects Of Rodent Species, Seed Species, And Predator Cues On Seed Fate, Kelly J. Sivy, Steven M. Ostoja, Eugene W. Schupp, Susan Durham
United States Geological Survey: Staff Publications
Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord’s kangaroo rat (Dipodomys ordii) and …
Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link
Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link
United States Geological Survey: Staff Publications
Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models …
Demographic Responses Of Least Terns And Piping Plovers To The 2011 Missouri River Flood—A Large-Scale Case Study, Michael J. Anteau, Mark H. Sherfy, Terry L. Shaffer, Rose J. Swift, Dustin L. Toy, Colin M. Dovichin
Demographic Responses Of Least Terns And Piping Plovers To The 2011 Missouri River Flood—A Large-Scale Case Study, Michael J. Anteau, Mark H. Sherfy, Terry L. Shaffer, Rose J. Swift, Dustin L. Toy, Colin M. Dovichin
United States Geological Survey: Publications
2011 led to substantial changes in abundance and distribution of unvegetated sand habitat. This river system is a major component of the breeding range for interior Least terns (Sternula antillarum; “terns”) and piping plovers (Charadrius melodus; “plovers”), both of which are Federally listed ground-nesting birds that prefer open, unvegetated sand and gravel nesting substrates on sandbars and shorelines. The 2011 flood inundated essentially all tern and plover nesting habitat during 2011, but it had potential to generate post-flood habitat conditions that favored use by terns and plovers in subsequent years. We compared several tern and plover demographic parameters during the …
The Role Of Demographic Compensation Theory In Incidental Take Assessments For Endangered Species, Conor P. Mcgowan, Mark R. Ryan, Michael C. Runge, Joshua J. Millspaugh, Jean Fitts Cochrane
The Role Of Demographic Compensation Theory In Incidental Take Assessments For Endangered Species, Conor P. Mcgowan, Mark R. Ryan, Michael C. Runge, Joshua J. Millspaugh, Jean Fitts Cochrane
United States Geological Survey: Staff Publications
Many endangered species laws provide exceptions to legislated prohibitions through incidental take provisions as long as take is the result of unintended consequences of an otherwise legal activity. These allowances presumably invoke the theory of demographic compensation, commonly applied to harvested species, by allowing limited harm as long as the probability of the species’ survival or recovery is not reduced appreciably. Demographic compensation requires some density-dependent limits on survival or reproduction in a species’ annual cycle that can be alleviated through incidental take. Using a population model for piping plovers in the Great Plains, we found that when the population …
Selenium In Birds, Harry M. Ohlendorf, Gary H. Heinz
Selenium In Birds, Harry M. Ohlendorf, Gary H. Heinz
United States Geological Survey: Staff Publications
Selenium (Se) is a metalloid trace element that birds and other wildlife need in small amounts for good health. The main purpose of this chapter is to interpret tissue concentrations of Se. However, because food is the main source of Se accumulation for birds and other wildlife, and because dietary concentrations for effects on bird reproduction have been reported, we also provide interpretive information on Se in the diet.
Se deficiencies in domestic poultry and livestock occur in some parts of the world and must be corrected by additions of Se to the diet. However, the range of dietary concentrations …
History Of Wildlife Toxicology And The Interpretation Of Contaminant Concentrations In Tissues, Barnett A. Rattner, Anton M. Scheuhammer, John E. Ellott
History Of Wildlife Toxicology And The Interpretation Of Contaminant Concentrations In Tissues, Barnett A. Rattner, Anton M. Scheuhammer, John E. Ellott
United States Geological Survey: Staff Publications
The detection and interpretation of contaminants in tissues of wildlife belongs to the field of toxicology, a scientific discipline with a long, intriguing, and illustrious history (reviewed by Hayes 1991, Gallo 2001, Gilbert and Hayes 2006, Wax 2006). We review its history briefly, to provide a context for understanding the use of tissue residues in toxicology, and to explain how their use has developed over time. Because so much work has been conducted on mercury, and dioxins and polychlorinated biphenyls (PCBs), separate case histories are included that describe the evolution of the use of tissue concentrations to assess exposure and …