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University of Nebraska - Lincoln

Stable isotopes

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Full-Text Articles in Physical Sciences and Mathematics

Establishment Of Invasive Black Carp (Mylopharyngodon Piceus) In The Mississippi River Basin: Identifying Sources And Year Classes Contributing To Recruitment, Gregory W. Whitledge, Patrick T. Kroboth, Duane C. Chapman, Quinton E. Phelps, Wes Sleeper, Jennifer Bailey, Jill A. Jenkins Sep 2022

Establishment Of Invasive Black Carp (Mylopharyngodon Piceus) In The Mississippi River Basin: Identifying Sources And Year Classes Contributing To Recruitment, Gregory W. Whitledge, Patrick T. Kroboth, Duane C. Chapman, Quinton E. Phelps, Wes Sleeper, Jennifer Bailey, Jill A. Jenkins

United States Geological Survey: Staff Publications

Black Carp (Mylopharyngodon piceus) was imported to the USA to control aquaculture pond snails. This species has escaped captivity and occurs in parts of the Mississippi River, several tributaries, and floodplain lakes, which is concerning due to potential competition with native fishes and predation on native mussels, many of which are imperiled. However, Black Carp captures have primarily been incidental by commercial fishers, and evidence of reproduction in the wild is limited. The objectives of this study were to assess relative abundance of aquaculture- origin and wild Black Carp using ploidy and otolith stable isotope analysis, identify spatial …


Prey Of Reintroduced Fishers And Their Habitat Relationships In The Cascades T Range, Washington, Mitchell A. Parsons, Jeffrey C. Lewis, Jonathan N. Pauli, Tara Chestnut, Jason I. Ransom, David O. Werntz, Laura R. Prugh Jan 2020

Prey Of Reintroduced Fishers And Their Habitat Relationships In The Cascades T Range, Washington, Mitchell A. Parsons, Jeffrey C. Lewis, Jonathan N. Pauli, Tara Chestnut, Jason I. Ransom, David O. Werntz, Laura R. Prugh

United States National Park Service: Publications

Conservation and recovery of forest carnivores requires an understanding of their habitat requirements, as well as requirements of their prey. In much of the western United States, trapping and habitat loss led to extirpations of fishers (Pekania pennanti) by the mid-20th century, and reintroductions are ongoing to restore fishers to portions of their former range. Fisher recovery in Washington State has been limited by isolation from other populations, but other potentially important factors, such as diet of fishers in this region and prey availability, have not been thoroughly investigated. We collected hair samples from potential prey and fishers for stable …


Middle Miocene Paleoenvironmental Reconstruction Of The Central Great Plains From Stable Carbon Isotopes In Large Mammals, Willow H. Nguy Jul 2017

Middle Miocene Paleoenvironmental Reconstruction Of The Central Great Plains From Stable Carbon Isotopes In Large Mammals, Willow H. Nguy

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Middle Miocene (18-12 Mya) mammalian faunas of the North American Great Plains contained a much higher diversity of apparent browsers than any modern biome. This has been attributed to greater primary productivity, which may have supported greater browser diversity that commonly corresponds with densely vegetated habitats. However, several lines of proxy evidence suggest that open woodlands or savannas dominated middle Miocene biomes; neither of which support many browsers today. Stable carbon isotopes in mammalian herbivore tooth enamel were used to reconstruct vegetation structure of middle Miocene biomes.

Stable carbon isotopes in C3 dominated environments reflect vegetation density and herbivores …


Partitioning Assimilatory Nitrogen Uptake In Streams: An Analysis Of Stable Isotope Tracer Additions Across Continents, J. L. Tank, E. Martí, T. Riis, D. Von Schiller, A. J. Reisinger, W. K. Dodds, M. R. Whiles, L. R. Ashkenas, W. B. Bowden, S. M. Collins, C. L. Crenshaw, T. A. Crowl, N. A. Griffiths, N. B. Grimm, S. K. Hamilton, S. L. Johnson, W. H. Mcdowell, B. M. Norman, E. J. Rosi, K. S. Simon, S. A. Thomas, J. R. Webster Jan 2017

Partitioning Assimilatory Nitrogen Uptake In Streams: An Analysis Of Stable Isotope Tracer Additions Across Continents, J. L. Tank, E. Martí, T. Riis, D. Von Schiller, A. J. Reisinger, W. K. Dodds, M. R. Whiles, L. R. Ashkenas, W. B. Bowden, S. M. Collins, C. L. Crenshaw, T. A. Crowl, N. A. Griffiths, N. B. Grimm, S. K. Hamilton, S. L. Johnson, W. H. Mcdowell, B. M. Norman, E. J. Rosi, K. S. Simon, S. A. Thomas, J. R. Webster

School of Natural Resources: Faculty Publications

Headwater streams remove, transform, and store inorganic nitrogen (N) delivered from surrounding watersheds, but excessive N inputs from human activity can saturate removal capacity. Most research has focused on quantifying N removal from the water column over short periods and in individual reaches, and these ecosystem-scale measurements suggest that assimilatory N uptake accounts for most N removal. However, cross-system comparisons addressing the relative role of particular biota responsible for incorporating inorganic N into biomass are lacking. Here we assess the importance of different primary uptake compartments on reach-scale ammonium (NH4+-N) uptake and storage across a wide range …


Isotopes From Fecal Material Provides Evidence Of Recent Diet Of Prairie Deer Mice, John W. Doudna, Brent J. Danielson Jun 2016

Isotopes From Fecal Material Provides Evidence Of Recent Diet Of Prairie Deer Mice, John W. Doudna, Brent J. Danielson

The Prairie Naturalist

Prairie deer mice are important predators in many agricultural systems, and through their diet they can help to regulate pest insect and weed populations. Our objective was to test whether fecal material is an effective means of detailing the foraging ecology of small mammals. We conducted three studies to evaluate the efficacy of this technique: 1) field-collected fecal material from unknown deer mice from late winter to early spring, 2) fecal material collected in an enclosure with mice fed a mix of C3 and C4 plant seeds, and 3) fecal material from tagged female mice in the field. We detected …


Macroinvertebrate Prey Availability And Food Web Dynamics Of Nonnative Trout In A Colorado River Tributary, Grand Canyon, Daniel P. Whiting, Craig P. Paukert, Brian D. Healy, Jonathan Spurgeon Sep 2014

Macroinvertebrate Prey Availability And Food Web Dynamics Of Nonnative Trout In A Colorado River Tributary, Grand Canyon, Daniel P. Whiting, Craig P. Paukert, Brian D. Healy, Jonathan Spurgeon

School of Natural Resources: Faculty Publications

Nonnative fishes have been linked to the decline of native fishes and may affect aquatic food webs through direct and indirect pathways. These concerns have led to efforts to remove nonnative Brown and Rainbow Trout, which are abundant in tributaries of the Colorado River, to enhance native fish communities. We sampled fish, benthic, and drifting macroinvertebrates in November 2010, January 2011, June 2011, and September 2011 to assess resource availability and to evaluate the effects of nonnative Brown and Rainbow Trout in a tributary of the Colorado River in the Grand Canyon. We evaluated trout diets from stomach samples collected …


Macroinvertebrate Prey Availability And Food Web Dynamics Of Nonnative Trout In A Colorado River Tributary, Grand Canyon, Daniel P. Whiting, Craig P. Paukert, Brian Healy, Jonathan Spurgeon May 2014

Macroinvertebrate Prey Availability And Food Web Dynamics Of Nonnative Trout In A Colorado River Tributary, Grand Canyon, Daniel P. Whiting, Craig P. Paukert, Brian Healy, Jonathan Spurgeon

School of Natural Resources: Faculty Publications

Nonnative fishes have been linked to the decline of native fishes and may affect aquatic food webs through direct and indirect pathways. These concerns have led to efforts to remove nonnative Brown and Rainbow Trout, which are abundant in tributaries of the Colorado River, to enhance native fish communities. We sampled fish, benthic, and drifting macroinvertebrates in November 2010, January 2011, June 2011, and Septem- ber 2011 to assess resource availability and to evaluate the effects of nonnative Brown and Rainbow Trout in a tributary of the Colorado River in the Grand Canyon. We evaluated trout diets from stomach samples …


Pore Water Extraction For Unsaturated Zone Isotope Research: An Investigation Using An Immiscible Displacement Fluid And A Centrifuge, Caitlin Burnett Weaver May 2014

Pore Water Extraction For Unsaturated Zone Isotope Research: An Investigation Using An Immiscible Displacement Fluid And A Centrifuge, Caitlin Burnett Weaver

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Accurate and reliable pore water extraction techniques are important to an array of scientific fields including, but not limited to, hydrogeology, soil science, and paleoenvironmental research. The aim of the current project is to test the applicability of an immiscible displacement extraction technique for stable isotopes of water under a range of textural, hydrologic, and chemical conditions. In this study, laboratory experiments were conducted to establish the extent to which the proposed method 1) achieves sufficient yield for laboratory isotopic analyses, 2) results in isotopic exchange between water and the displacement fluid, 3) conserves initial isotopic compositions of spike test …


Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses, Kenneth J. Sulak, J. J. Berg, M. Randall Mar 2012

Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses, Kenneth J. Sulak, J. J. Berg, M. Randall

United States Geological Survey: Staff Publications

Stable 13C, 15N, and 34S isotopes were analyzed to define the feeding habitats of Acipenser oxyrinchus desotoi in the Suwannee and Yellow River populations. For the majority (93.9%) of Suwannee sub adults and adults, 13C and 34S signatures indicate use of nearshore marine waters as primary winter feeding habitat, probably due to the limiting size of the Suwannee Sound estuary. In the Yellow River population, 13C isotope signatures indicate that adults remain primarily within Pensacola Bay estuary to feed in winter, rather than immigrating to the open Gulf of Mexico. A minor Suwannee River subset (6% of …


Ontogenetic Dietary Information Of The California Sea Lion (Zalophus Californianus) Assessed Using Stable Isotope Analysis, Anthony J. Orr, Seth D. Newsome, Jeffrey L. Laake, Glenn R. Vanblaricom, Robert L. Delong Jan 2011

Ontogenetic Dietary Information Of The California Sea Lion (Zalophus Californianus) Assessed Using Stable Isotope Analysis, Anthony J. Orr, Seth D. Newsome, Jeffrey L. Laake, Glenn R. Vanblaricom, Robert L. Delong

United States Department of Commerce: Staff Publications

We used stable carbon (δ13C) and nitrogen (δ15N) isotopes to examine ontogenetic dietary changes in 289 California sea lions (Zalophus californianus) at San Miguel Island, California during 2004–2007. Tissues analyzed included fur, red blood cells, plasma, and serum. For all tissues, pups had higher δ15N values and lower δ13C values compared to adults, which indicated that pups were feeding higher trophically than older conspecifics and on a lipid-rich milk diet prior to weaning. Yearling δ15N values were slightly lower than pup or nearly indistinguishable from adult values depending …


Ecology, Stable Isotopes, And Management Of Grassland Songbirds At National Park Service Properties On The Great Plains, Sarah E. Rehme Jul 2010

Ecology, Stable Isotopes, And Management Of Grassland Songbirds At National Park Service Properties On The Great Plains, Sarah E. Rehme

School of Natural Resources: Dissertations, Theses, and Student Research

Grassland ecosystems have been severely reduced and grassland bird populations have experienced consistent declines. National Park Service (NPS) properties on the Great Plains provide breeding habitat for grassland songbirds, though little is known about the quality of this habitat. A short-term study on songbirds at three NPS properties complemented current monitoring, providing an among park comparison addressing grassland bird productivity and fidelity relative to NPS property size. During 2008-2009, I assessed avian species richness, and estimated bird density and grassland songbird nest success. Bird species richness was greatest at small and medium sites, while number of nesting obligate species was …


Seasonal Changes In Depth Of Water Uptake For Encroaching Trees Juniperus Virginiana And Pinus Ponderosa And Two Dominant C4 Grasses In A Semiarid Grassland, Kathleen D. Eggemeyer, Tala Awada, F. Edwin Harvey, David A. Wedin, Xinhua Zhou, C. William Zanner Jan 2009

Seasonal Changes In Depth Of Water Uptake For Encroaching Trees Juniperus Virginiana And Pinus Ponderosa And Two Dominant C4 Grasses In A Semiarid Grassland, Kathleen D. Eggemeyer, Tala Awada, F. Edwin Harvey, David A. Wedin, Xinhua Zhou, C. William Zanner

School of Natural Resources: Faculty Publications

We used the natural abundance of stable isotopic ratios of hydrogen and oxygen in soil (0.05–3 m depth), plant xylem and precipitation to determine the seasonal changes in sources of soil water uptake by two native encroaching woody species (Pinus ponderosa P. & C. Lawson, Juniperus virginiana L.), and two C4 grasses (Schizachyrium scoparium (Michx.) Nash, Panicum virgatum L.), in the semiarid Sandhills grasslands of Nebraska. Grass species extracted most of their water from the upper soil profile (0.05–0.5 m). Soil water uptake from below 0.5 m depth increased under drought, but appeared to be minimal in …


Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak Sep 2006

Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak

United States Geological Survey: Staff Publications

Deep-water (307–697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of two specimens, and to establish that they were several centuries old. Bands were delaminated in KOH and analyzed for carbon and nitrogen stable isotopes. Carbon values ranged from _16.4‰ to _15.7‰; the oldest specimen displayed the largest range in values. Nitrogen values ranged from 7.7‰ to 8.6‰. …


Stable Hydrogen Isotope Analysis Of Bat Hair As Evidence For Seasonal Molt And Long-Distance Migration, Paul M. Cryan, Michael A. Bogan, Robert O. Rye, Gary P. Landis, Cynthia L. Kester Jan 2004

Stable Hydrogen Isotope Analysis Of Bat Hair As Evidence For Seasonal Molt And Long-Distance Migration, Paul M. Cryan, Michael A. Bogan, Robert O. Rye, Gary P. Landis, Cynthia L. Kester

United States Geological Survey: Staff Publications

Although hoary bats (Lasiurus cinereus) are presumed to be migratory and capable of long-distance dispersal, traditional marking techniques have failed to provide direct evidence of migratory movements by individuals. We measured the stable hydrogen isotope ratios of bat hair (∂Dh) and determined how these values relate to stable hydrogen isotope ratios of precipitation (∂Dp). Our results indicate that the major assumptions of stable isotope migration studies hold true for hoary bats and that the methodology provides a viable means of determining their migratory movements. We present evidence that a single annual molt occurs in L. cinereus …


Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins Apr 2001

Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins

USDA Wildlife Services: Staff Publications

Black bear (Ursus americanus) damage to managed conifer stands during the spring in the U.S. Pacific Northwest is a continuing management concern. Because bear damage to managed conifers may reflect the limited availability of nutritious foods, supplemental feeding has been used to decrease damage. Highly palatable, pelleted feed is provided ad libitum from April until late June when berries ripen and such damage stops. We examined black bear use of supplemental feed during the spring and summer of 1998 and 1999 in western Washington. Bears were captured in areas where supplemental feed was provided and in control areas …


Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins Mar 2001

Impacts Of Supplemental Feeding On The Nutritional Ecology Of Black Bears, Steven T. Partridge, Dale L. Nolte, Georg J. Ziegltrum, Charles T. Robbins

USDA Wildlife Services: Staff Publications

Black bear (Ursus americanus) damage to managed conifer stands during the spring in the U.S. Pacific Northwest is a continuing management concern. Because bear damage to managed conifers may reflect the limited availability of nutritious foods, supplemental feeding has been used to decrease damage. Highly palatable, pelleted feed is provided ad libitum from April until late June when berries ripen and such damage stops. We examined black bear use of supplemental feed during the spring and summer of 1998 and 1999 in western Washington. Bears were captured in areas where supplemental feed was provided and in control areas …