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The C and N isotopes of feathers from two subspecies of willow warblers Phylloscopus trochilus trochilus and Phylloscopus trochilus acredula) are isotopically distinct. Our analysis of 138 adult males from 14 sites distributed across Sweden shows that the mean delta15N and delta13C values of subspecies acredula (from latitudes above 63 degrees N) were(More)
We determine paleoelevation of the Sierra Nevada, California, by tracking the effect of topography on precipitation, as recorded in hydrogen isotopes of kaolinite exposed in gold-bearing river deposits from the Eocene Yuba River. The data, compared with the modern isotopic composition of precipitation, show that about 40 to 50 million years ago the Sierra(More)
Stable oxygen isotope ratios (delta(18)O) of Precambrian cherts have been used to establish much of our understanding of the early climate history of Earth and suggest that ocean temperatures during the Archaean era ( approximately 3.5 billion years ago) were between 55 degrees C and 85 degrees C (ref. 2). But, because of uncertainty in the delta(18)O of(More)
 Over the past century, overgrazing and drought in New Mexico's Jornada Basin has promoted the replacement of native black grama (Bouteloua eriopoda Torr.) grass communities by shrubs, primarily mesquite (Prosopis glandulosa Torr.). We investigated the effects of shrub expansion on the distribution, origin, turnover, and quality of light (LFC) and heavy(More)
Orographic precipitation of Pacific-sourced moisture creates a rain shadow across the central part of the Sierra Nevada (California) that contrasts with the southern part of the range, where seasonal monsoonal precipitation sourced to the south obscures this rain shadow effect. Orographic rainout systematically lowers the hydrogen isotope composition of(More)
The Yarlung Tsangpo–Brahmaputra river drains a large portion of the Himalaya and southern Tibetan plateau, including the eastern Himalayan syntaxis, one of the most tectonically active regions on the globe. We measured the solute chemistry of 161 streams and major tributaries of the Tsangpo–Brahmaputra to examine the effect of tectonic, climatic, and(More)
We used the natural abundance of stable isotopes (carbon and hydrogen) in the feathers of a neotropical migrant songbird to determine where birds from particular breeding areas spend the winter and the extent to which breeding populations mix in winter quarters. We show that most birds wintering on western Caribbean islands come from the northern portion of(More)
 To determine whether stable isotopes can be used for identifying the geographic origins of migratory bird populations, we examined the isotopic composition of hydrogen (deuterium, δD), carbon (δ13C), and strontium (δ87Sr) in tissues of a migratory passerine, the black-throated blue warbler (Dendroica caerulescens), throughout its breeding range in eastern(More)
Oxygen isotope zoning was examined within garnet with the use of the stable isotope laser probe. Four metamorphic garnets from the regional metamorphic terrane in Vermont and the skarn deposit at Carr Fork, Utah, were examined and were found to be concentrically zoned in delta(18)O values. The largest variations in delta(18)O values were observed in the(More)
We used carbon and nitrogen isotopes to investigate changes in the diet of California condors from the Pleistocene to the recent. During the Pleistocene, condors from California fed on both terrestrial megafauna and marine mammals. Early accounts reported condors feeding on the carcasses of marine mammals, but by the late 1700s, condor diets had shifted(More)