نتایج جستجو برای: δ15n
تعداد نتایج: 888 فیلتر نتایج به سال:
Understanding reproductive performance in ecologically impoverished vs. more sustained anthropogenic habitats is critical to assess population health status and to develop land use and conservation management strategies. We compared resourcebased maternal effects, reproductive performance, and offspring quality in a model migratory passerine bird, the European starling (Sturnus vulgaris). We as...
Complete panmixia across the entire range of a species is a relatively rare phenomenon; however, this pattern may be found in species that have limited philopatry and frequent dispersal. American white pelicans (Pelecanus erythrorhyncos) provide a unique opportunity to examine the role of long-distance dispersal in facilitating gene flow in a species recently reported as panmictic across its br...
Nitrate input to a river is largely controlled by land use in its catchment. We compared the information carried by the isotopic signatures of nitrate in 12 Baltic rivers, in relation to the vegetation cover, land use, and fertilization of agricultural land of their catchments. We found isotope values in nitrate ranging from −2 to 14‰ for δ15N and 8 to 25‰ for δ18O. The annual variability of ri...
Alloparenting, when individuals other than the mother assist with infant care, can vary between and within populations and has potential fitness costs and benefits for individuals involved. We investigated the effects of alloparenting on the speed with which infants were weaned, a potential component of maternal fitness because of how it can affect inter-birth intervals, in wild chimpanzees (Pa...
Seabirds are marine top predators and accumulate high levels of metals and metalloids in their tissues. Contamination by metals in the highly productive offshore region has become a matter of public concern. It is home to 80% of the seabird population in the U.S.A., 95% of northern fur seals (Callorhinus ursinus), and major populations of Steller sea lions (Eumetopias jubatus), walruses (Odoben...
Documenting habitat-related patterns in foraging behaviour at the individual level and over large temporal scales remains challenging for large herbivores. Stable isotope analysis could represent a valuable tool to quantify habitat-related foraging behaviour at the scale of individuals and over large temporal scales in forest dwelling large herbivores living in coastal environments, because the...
We analyzed stable isotopes of carbon and nitrogen to investigate the trophic structure of the subtidal food web around the Mingan Islands, northern Gulf of St. Lawrence, eastern Canada. All benthic consumers were enriched in 13C (mean δ13C of –17.1% ) compared to particulate organic matter (POM: –23.3% ). Nitrogen stable isotope ratios ranged from 6% to 14% and the organisms studied fell into ...
Aspects of between-individual trophic niche width can be explored through the isotopic niche concept. In many cases isotopic variability can be influenced by the scale of sampling and biological characteristics including body size or sex. Sample size-corrected (SEAc) and Bayesian (SEAb) standard ellipse areas and generalised least squares (GLS) models were used to explore the spatial variabilit...
Nitrate content of surface waters results from complex mixing of multiple sources, whose signatures can be modified through N reactions occurring within the different compartments of the whole catchment. Despite this complexity, the determination of nitrate origin is the first and crucial step for water resource preservation. Here, for the first time, we combined at the catchment scale stable i...
Reconstructing ancient diets and the use of animals and plants augment our understanding of how humans adapted to different environments. Yunnan Province in southwest China is ecologically and environmentally diverse. During the Neolithic and Bronze Age periods, this region was occupied by a variety of local culture groups with diverse subsistence systems and material culture. In this paper, we...
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