نتایج جستجو برای: stable isotope

تعداد نتایج: 281992  

Journal: :American journal of physical anthropology 2016
Kerry L Sayle W Derek Hamilton Gordon T Cook Philippa L Ascough Hildur Gestsdóttir Thomas H McGovern

OBJECTIVES A previous multi-isotope study of archaeological faunal samples from Skútustaðir, an early Viking age settlement on the southern shores of Lake Mývatn in north-east Iceland, demonstrated that there are clear differences in δ(34)S stable isotope values between animals deriving their dietary protein from terrestrial, freshwater, and marine reservoirs. The aim of this study was to use t...

Journal: :Ecology 2016
Philip D McLoughlin Kenton Lysak Lucie Debeffe Thomas Perry Keith A Hobson

Sea-to-land nutrient transfers can connect marine food webs to those on land, creating a dependence on marine webs by opportunistic species. We show how nitrogen, imported by gray seals, Halichoerus grypus, and traced through stable isotope (δ15 N) measurements in marram grass, Ammophila breviligulata, significantly alters foraging behavior of a free-roaming megaherbivore (feral horses, Equus f...

2018
Aurelie Manin Eduardo Corona-M Michelle Alexander Abigail Craig Erin Kennedy Thornton Dongya Y Yang Michael Richards Camilla F Speller

The turkey (Meleagris gallopavo) represents one of the few domestic animals of the New World. While current research points to distinct domestication centres in the Southwest USA and Mesoamerica, several questions regarding the number of progenitor populations, and the timing and intensity of turkey husbandry remain unanswered. This study applied ancient mitochondrial DNA and stable isotope (δ1...

Journal: :Science 2005
Stuart Bearhop Wolfgang Fiedler Robert W Furness Stephen C Votier Susan Waldron Jason Newton Gabriel J Bowen Peter Berthold Keith Farnsworth

There have been numerous recent observations of changes in the behavior and dynamics of migratory bird populations, but the plasticity of the migratory trait and our inability to track small animals over large distances have hindered investigation of the mechanisms behind migratory change. We used habitat-specific stable isotope signatures to show that recently evolved allopatric wintering popu...

2017
Wolfgang Stinnesbeck Julia Becker Fabio Hering Eberhard Frey Arturo González González Jens Fohlmeister Sarah Stinnesbeck Norbert Frank Alejandro Terrazas Mata Martha Elena Benavente Jerónimo Avilés Olguín Eugenio Aceves Núñez Patrick Zell Michael Deininger

Preceramic human skeletal remains preserved in submerged caves near Tulum in the Mexican state of Quintana Roo, Mexico, reveal conflicting results regarding 14C dating. Here we use U-series techniques for dating a stalagmite overgrowing the pelvis of a human skeleton discovered in the submerged Chan Hol cave. The oldest closed system U/Th age comes from around 21 mm above the pelvis defining th...

Journal: :Ecology 2008
David J Hoeinghaus Steven C Zeug

Over the last few decades, the use of stable isotope ratios in ecological studies has increased greatly, most notably in the area of trophic ecology and food webs (Peterson and Fry 1987, Fry 2006). However, applications of stable isotopes in food web studies have been mostly qualitative to date, prompting the recent development of quantitative approaches to investigate different aspects of trop...

2011
Caroline M. Hammerschlag-Peyer Lauren A. Yeager Márcio S. Araújo Craig A. Layman

Ontogenetic niche shifts occur across diverse taxonomic groups, and can have critical implications for population dynamics, community structure, and ecosystem function. In this study, we provide a hypothesis-testing framework combining univariate and multivariate analyses to examine ontogenetic niche shifts using stable isotope ratios. This framework is based on three distinct ontogenetic niche...

2011
Ian D. Clark

1. Background 2. Elements, Nuclides, and Stable Isotopes 3. The Mass Spectrometer and Isotope Ratio Measurement 4. Isotope Fractionation 5. Temperature and Fractionation 6. Stable Isotopes in the Hydrologic Cycle 7. O in Minerals and Rocks 8. C and Carbon Cycling 9. N Cycling in Watersheds 10.S and the Sulfur Cycle 11. Chlorine and Bromine Isotopes 12. Light Lithophile Elements: δLi and δB Glos...

2007
David B. Rowley Carmala N. Garzione

The quantitative estimation of paleoaltitude has become an increasing focus of Earth scientists because surface elevation provides constraints on the geodynamic mechanisms operating in mountain belts, as well as the influence of mountain belt growth on regional and global climate. The general observation of decreasing δ18O and δ2H values in rainfall as elevation increases has been used in both ...

Journal: :Geochimica et Cosmochimica Acta 2008

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