Dietary segregation is essential for the coexistence of closely related species of animals. However, little is known about how changes in availability of food resources might affect trophic interactions of wild animals breeding in sympatry. Here, we examined how interannual variations in relative food availability (as reflected in blood levels of stress hormone corticosterone, CORT) affect food partitioning (assessed via a comparison of stable isotope δ(15)N and δ(13)C ratios of blood) between the common murre (Uria aalge) and thick-billed murre (Uria lomvia), breeding on a single colony in the Bering Sea. During a 6-year study, CORT varied among years but not between species, whereas stable isotope ratios varied among years and between species. Isotopic distance between species increased with increasing CORT. These results indicate that, when food was not limiting, both species relied on similar food resources. As foraging conditions deteriorated, murres diverged in their diets. We conclude that the degree of dietary segregation between Uria spp. varies with changes in the availability of food and is greatest during food shortages.
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http://dx.doi.org/10.1098/rsbl.2011.1020 | DOI Listing |
Curr Zool
December 2024
Department of Environmental Science and Policy, University of Milan, Milan, Italy.
Niche theory predicts that closely related and ecologically similar species with overlapping distribution ranges can coexist through resource partitioning that limits interspecific competition. However, studies examining the mechanisms promoting coexistence of top predators at a large geographical scale are still scant. Here, we describe the foraging ecology of 3 sympatric owl species (Northern long-eared owl [], Tawny owl [], Eurasian eagle owl []) in the Mediterranean Basin.
View Article and Find Full Text PDFHeliyon
October 2024
Institute of Applied Science and Technology, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana.
The sesame seed contains oil, protein, dietary fibre, and several minerals and it is also a store of lignans. Lignans are key selection factors for sesame quality due to their health, nutritive and market value. In Ghana sesame growers rely on wild or undocumented planting seeds which are of mixed colouration and its lignan content is ambiguous.
View Article and Find Full Text PDFNeurol Genet
December 2024
From the Department of Neurology (T.B., J.-J.R., F.T.B.), University Hospital Leipzig; Institute of Human Genetics (H.F., R.A.J.), University Hospital Leipzig; Department of Psychiatry (C.P., M.K.), University of Leipzig; Hospital for Psychiatry (M.K.), Psychotherapy und Psychosomatics, Klinikum Glauchau; Department of Pediatrics (S.B.), University Hospital Leipzig; and Centre for Rare Diseases (S.B., F.T.B.), University Hospital Leipzig, Germany.
J Invertebr Pathol
February 2025
Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA.
Cry2Ab2 is a Bacillus thuringiensis (Bt) protein that has been pyramided with Cry1A.105 in transgenic maize and Cry1Ac in cotton to control some major lepidopteran pests including the corn earworm/bollworm, Helicoverpa zea (Boddie). However, the widespread occurrence of resistance of this pest to the pyramided Cry1A/Cry2A crops in the southern region of the United State has become a threat to the sustainability of the technology.
View Article and Find Full Text PDFJ Clin Lipidol
October 2024
Department of Biological Sciences, National University of Medical Sciences, Rawalpindi 46000, Pakistan. Electronic address:
Sitosterolemia is a rare autosomal recessive disorder characterized by impaired excretion of plant sterols, leading to their accumulation in tissues and organs. We identified a hitherto unreported homozygous variant, in ATP-binding cassette sub-family G member 5 (ABCG5) (NM_022436.3) c.
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