Naturally occurring stable isotopes in foodwebs can be used to determine the relative contributions of endogenous and exogenous nutrients to avian eggs in cases where birds move between isotopically distinct biomes or habitats to breed. We measured δ13C and δ15N values in somatic muscle tissues and eggs of Barrow’s goldeneye (Bucephala islandica) together with those isotope values in amphipods ...

Large areas of Namibia are covered by farmland, which is also used by game and predator species. Because it can cause conflicts with farmers when predators, such as cheetahs (Acinonyx jubatus), hunt livestock, we assessed whether livestock constitutes a significant part of the cheetah diet by analysing the stable isotope composition of blood and tissue samples of cheetahs and their potential pr...

This study seeks to understand how humans impact the dietary patterns of eight free-ranging vervet monkey (Chlorocebus pygerythrus) groups in South Africa using stable isotope analysis. Vervets are omnivores that exploit a wide range of habitats including those that have been anthropogenically-disturbed. As humans encroach upon nonhuman primate landscapes, human-nonhuman primate interconnection...

Information on the contribution of various soil nitrogen (N) sources to plant N uptake is often needed for the implementation of sustainable or site-specific management practices in agriculture. Considering the limitations of traditional methods in meeting these needs, this study investigated the potential of leaf δ15N as an early indicator of nutrient deficiency in cotton. The spatial and temp...

Stable carbon and nitrogen isotopes were used to obtain estimates of the contribution of natural and supplemental feeds to the nutrition of Oreochromis niloticus in ponds (free-swimming or caged) receiving different inputs in Sagana, Kenya. Three dietary treatments were employed in the pond study: 1) the test diet; 2) a pig finisher diet; and 3) a rice bran diet. Feeding rates and fertilization...

To clarify the effect of irrigation drainage from paddy fields on an estuarine tidal flat (Ushibashi Estuary, Miyagi Prefecture),we investigated carbon and nitrogen stable isotope ratios (δ13C δ15N) organic matters within fields, agricultural channels (rivers),and flats, those 18 species benthic consumers March to December 2020. The sediments had lower δ13C δ15N at riverward station (δ13C: -27....

Identifying the origin of NOx emissions, their transformation into nitrate (NO3−) and its atmospheric deposition is important to better understand impacts air pollution on environment human health, a local regional scale. We measured isotopes (δ15N, δ18O NO3−) in precipitation samples tropical station Brazil 2019–2020 combined them with chemical, geospatial meteorological data trace sources tow...

Blood stable isotope compositions in birds reflect the dietary isotopic signature at the time of the cellular blood synthesis. Several studies suggest that stable isotope ratios of some elements such as nitrogen (δ15N) can change in response to individual metabolic and physiological conditions. Using a wind tunnel experiment we tested if endurance flight in birds alters the metabolic state and ...

Objectives During the Middle Ages, Portugal witnessed unprecedented socioeconomic and religious changes under transitioning political rule. The implications of changing ruling powers for urban food systems individual diets in medieval is poorly understood. This study aimed to elucidate dietary impact Islamic Christian conquests. Materials Methods Radiocarbon dating, peptide mass fingerprinting ...

In the high-productivity subarctic ocean, phytoplankton growth is assumed to rely mainly on nitrate, based snapshot observations conducted in spring or summer. However, year-round utilization of nitrate and ammonium by remains unexplored. Here, we show seasonal transition dominant nitrogen source for using isotopic composition (δ15N) ammonium, sinking particles northwestern North Pacific. To de...