Barbara Helm results 19
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Laser-based isotope profiling in avian tissues: a high-resolution method for ecological reconstructionNARA Subscribed
Keratinous and bony tissues preserve ecological information, yet conventional isotope methods often lack the spatial resolution to detect fine-scale dietary or habitat transitions. Here, we present a high-resolution framework using laser ablation isotope ratio mass spectrometry (LA-IRMS) to reconstruct stable carbon isotope (δ 13 C) chronologies in feathers, claws, bills, and cranial bones across three avian species. LA-IRMS m...
Female chronotype relates to lay date but not fitness in an island population of great titsNARA Subscribed
Organisms use diel timing mechanisms to anticipate predictable daily environmental fluctuations, such as the start and end of the day light period. There is often ample intraspecific variation in this diel timing, with individuals being consistently active earlier or later than others in the population and therefore having early or late chronotypes. In tit species, early-active males have higher rates of extrapair paternity, a...
Conservation‐focused mapping of avian migratory routes using a pan‐European automated telemetry networkNARA Subscribed
Accelerated biodiversity loss has destabilized functional links within and between ecosystems. Species that cross different ecosystems during migration between breeding and nonbreeding sites are particularly sensitive to global change because they are exposed to various, often ecosystem‐specific, threats. Because these threats have lethal and nonlethal effects on populations, many migratory species are declining, making this g...
Drivers of nest site selection and breeding success in an Alpine ground-nesting songbirdNARA Subscribed
Birds breeding in high-Alpine habitats must select a suitable breeding site and achieve successful reproduction within a restricted time. During four breeding seasons, we monitored nest sites of the Northern Wheatear ( Oenanthe oenanthe ), a high-Alpine long-distance migrant. We investigated how ecological factors predicted the selection of a site for nesting within the home range, using conditional logistic regression. Birds...
Thick-billed Murres in breeding pairs migrate and overwinter far apart but in similar photic environmentsNARA Subscribed
Scheduling between mates in species with long-term pair bonds can be essential for positive fitness. The annual cycle in photoperiod is the primary environmental cue used by many animals to synchronize behavior and physiology among members of a population, and animals that migrate must have similar annual schedules to ensure successful breeding. However, we know little about whether members of mated pairs in migratory species...
Avian migration clocks in a changing worldNARA Subscribed
Avian long-distance migration requires refined programming to orchestrate the birds’ movements on annual temporal and continental spatial scales. Programming is particularly important as long-distance movements typically anticipate future environmental conditions. Hence, migration has long been of particular interest in chronobiology. Captivity studies using a proxy, the shift to nocturnality during migration seasons (i.e., mi...
The highly conserved YrdC domain-containing protein (YRDC) interacts with the well-described KEOPS complex, regulating specific tRNA modifications to ensure accurate protein synthesis. Previous studies have linked the KEOPS complex to a role in promoting telomere maintenance and controlling genome integrity. Here, we report on a newborn with a severe neonatal progeroid phenotype including generalized loss of subcutaneous fat,...
Moult of overwintering Wood Warblers Phylloscopus sibilatrix in an annual-cycle perspectiveNARA Subscribed
Wood Warblers, an Afro-Palearctic migrant species, are declining steadily in Europe likely due to mortality outside their breeding grounds. However, little is known about their overwintering, and records about the sensitive life-cycle stage of moult in Africa are practically absent. To fill this gap, we report on moult of Wood Warblers captured over two winters (January–February) in 2019–2020 in Cameroon. We caught 14 individu...
Bitter fruits of hard labour: diet metabarcoding and telemetry reveal that urban songbirds travel further for lower-quality foodNARA Subscribed
Rapidly increasing urbanisation requires mitigation against associated losses of biodiversity and species abundance. In urban-breeding birds, altered food availability for nestlings is thought to reduce reproductive success compared to forest populations. To compensate for shortages of preferred foods, urban parents could increase their search effort for optimal diets or provision other foods. Here, we used telemetry and faeca...
TRY plant trait database – enhanced coverage and open accessNARA Subscribed
Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodivers...
Comparative studies of closely related taxa can provide insights into the evolutionary forces that shape genome evolution and the prevalence of convergent molecular evolution. We investigated patterns of genetic diversity and differentiation in stonechats (genus Saxicola ), a widely distributed avian species complex with phenotypic variation in plumage, morphology and migratory behaviour, to ask whether similar genomic regions...
EPMA-World Congress 2015NARA Subscribed
Stonechats (genus Saxicola ) are passerine birds with an extraordinarily large breeding distribution. Recent studies provide strong evidence that the taxon shows far greater geographic differentiation than originally suspected, with African, Siberian and European stonechats forming distinct, monophyletic groups that have been suggested to be species in their own right. Here, we present additional data on the geographic differe...
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