The Experts below are selected from a list of 27369 Experts worldwide ranked by ideXlab platform
Xin Wang - One of the best experts on this subject based on the ideXlab platform.
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stochastic simulations reveal few green wave surfing populations among spring migrating herbivorous waterfowl
Nature Communications, 2019Co-Authors: Xin Wang, Lei Cao, Anthony D Fox, Richard A Fuller, Larry Griffin, Carl Mitchell, Yunlin Zhao, Ounkyong Moon, David CabotAbstract:Tracking seasonally changing resources is regarded as a widespread proximate mechanism underpinning Animal Migration. Migrating herbivores, for example, are hypothesized to track seasonal foliage dynamics over large spatial scales. Previous investigations of this green wave hypothesis involved few species and limited geographical extent, and used conventional correlation that cannot disentangle alternative correlated effects. Here, we introduce stochastic simulations to test this hypothesis using 222 individual spring Migration episodes of 14 populations of ten species of geese, swans and dabbling ducks throughout Europe, East Asia, and North America. We find that the green wave cannot be considered a ubiquitous driver of herbivorous waterfowl spring Migration, as it explains observed Migration patterns of only a few grazing populations in specific regions. We suggest that ecological barriers and particularly human disturbance likely constrain the capacity of herbivorous waterfowl to track the green wave in some regions, highlighting key challenges in conserving migratory birds.
Miriam Liedvogel - One of the best experts on this subject based on the ideXlab platform.
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the genetics and epigenetics of Animal Migration and orientation birds butterflies and beyond
The Journal of Experimental Biology, 2019Co-Authors: Christine Merlin, Miriam LiedvogelAbstract:ABSTRACT Migration is a complex behavioural adaptation for survival that has evolved across the Animal kingdom from invertebrates to mammals. In some taxa, closely related migratory species, or even populations of the same species, exhibit different migratory phenotypes, including timing and orientation of Migration. In these species, a significant proportion of the phenotypic variance in migratory traits is genetic. In others, the migratory phenotype and direction is triggered by seasonal changes in the environment, suggesting an epigenetic control of their Migration. The genes and epigenetic changes underpinning migratory behaviour remain largely unknown. The revolution in (epi)genomics and functional genomic tools holds great promise to rapidly move the field of Migration genetics forward. Here, we review our current understanding of the genetic and epigenetic architecture of migratory traits, focusing on two emerging models: the European blackcap and the North American monarch butterfly. We also outline a vision of how technical advances and integrative approaches could be employed to identify and functionally validate candidate genes and cis-regulatory elements on these and other migratory species across both small and broad phylogenetic scales to significantly advance the field of genetics of Animal Migration.
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Programmed and flexible: long-term Zugunruhe data highlight the many axes of variation in avian migratory behaviour
Journal of Avian Biology, 2017Co-Authors: Benjamin M. Van Doren, Miriam Liedvogel, Barbara HelmAbstract:Studies of Zugunruhe – the ‘migratory restlessness’ behaviour of captive birds – have been integral to our understanding of Animal Migration, revealing an inherited propensity to migrate and an endogenous timing and navigation system. However, differences between Zugunruhe in captivity and Migration in the wild call for more data, in particular on variation within and among taxa with diverse Migration strategies. Here, we characterise Zugunruhe in a long-term dataset of activity profiles from stonechats (genus Saxicola) with diverse migratory phenotypes (976 Migration periods from 414 birds), using a flexible and consistent quantitative approach based on changepoint analysis. For east African, Austrian, Irish, and Siberian stonechats and hybrids, we report key inter-population differences in the occurrence, timing, and intensity of Zugunruhe. In line with expectations, we found the highest Zugunruhe intensity in the longest-distance migrants, more variable patterns in short-distance migrants, and intermediate characteristics of hybrids relative to their parental groups. Inter-population differences imply high evolutionary lability of Zugunruhe timing within a robustly structured annual cycle. However, counter to theory, Irish partial migrants showed no segregation between migrant and resident individuals, and previously reported nocturnal restlessness was confirmed for resident African stonechats. Further features of nocturnal restlessness that did not align with migratory behaviour of stonechats were juvenile nocturnal restlessness even prior to postjuvenile moult, and protandry in spring, although stonechats winter in heterosexual pairs. Importantly, Zugunruhe of all populations declined with age, and the intensity of an individual bird's Zugunruhe was correlated with activity levels during other parts of the annual cycle. Our results confirm endogenous, population-specific Migration programmes but also reveal apparent discrepancies between Zugunruhe and Migration in the wild. We thus highlight both the continued potential of Zugunruhe study and the need for circumspect interpretation when using migratory restlessness to make inferences about Migration in the wild.
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characterisation of a transcriptome to find sequence differences between two differentially migrating subspecies of the willow warbler phylloscopus trochilus
BMC Genomics, 2013Co-Authors: Max Lundberg, Miriam Liedvogel, John Boss, Bjorn Canback, Keith W Larson, Mats Grahn, Susanne Akesson, Staffan Bensch, Anthony P H WrightAbstract:Background: Animal Migration requires adaptations in morphological, physiological and behavioural traits. Several of these traits have been shown to possess a strong heritable component in birds, but little is known about their genetic architecture. Here we used 454 sequencing of brain-derived transcriptomes from two differentially migrating subspecies of the willow warbler Phylloscopus trochilus to detect genes potentially underlying traits associated with Migration. Results: The transcriptome sequencing resulted in 1.8 million reads following filtering steps. Most of the reads (84%) were successfully mapped to the genome of the zebra finch Taeniopygia gutatta. The mapped reads were situated within at least 12,101 predicted zebra finch genes, with the greatest sequencing depth in exons. Reads that were mapped to intergenic regions were generally located close to predicted genes and possibly located in uncharacterized untranslated regions (UTRs). Out of 85,000 single nucleotide polymorphisms (SNPs) with a minimum sequencing depth of eight reads from each of two subspecies-specific pools, only 55 showed high differentiation, confirming previous studies showing that most of the genetic variation is shared between the subspecies. Validation of a subset of the most highly differentiated SNPs using Sanger sequencing demonstrated that several of them also were differentiated between an independent set of individuals of each subspecies. These SNPs were clustered in two chromosome regions that are likely to be influenced by divergent selection between the subspecies and that could potentially be associated with adaptations to their different migratory strategies. Conclusions: Our study represents the first large-scale sequencing analysis aiming at detecting genes underlying migratory phenotypes in birds and provides new candidates for genes potentially involved in Migration.
David Cabot - One of the best experts on this subject based on the ideXlab platform.
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stochastic simulations reveal few green wave surfing populations among spring migrating herbivorous waterfowl
Nature Communications, 2019Co-Authors: Xin Wang, Lei Cao, Anthony D Fox, Richard A Fuller, Larry Griffin, Carl Mitchell, Yunlin Zhao, Ounkyong Moon, David CabotAbstract:Tracking seasonally changing resources is regarded as a widespread proximate mechanism underpinning Animal Migration. Migrating herbivores, for example, are hypothesized to track seasonal foliage dynamics over large spatial scales. Previous investigations of this green wave hypothesis involved few species and limited geographical extent, and used conventional correlation that cannot disentangle alternative correlated effects. Here, we introduce stochastic simulations to test this hypothesis using 222 individual spring Migration episodes of 14 populations of ten species of geese, swans and dabbling ducks throughout Europe, East Asia, and North America. We find that the green wave cannot be considered a ubiquitous driver of herbivorous waterfowl spring Migration, as it explains observed Migration patterns of only a few grazing populations in specific regions. We suggest that ecological barriers and particularly human disturbance likely constrain the capacity of herbivorous waterfowl to track the green wave in some regions, highlighting key challenges in conserving migratory birds.
Olivier Gilg - One of the best experts on this subject based on the ideXlab platform.
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flexibility in otherwise consistent non breeding movements of a long distance migratory seabird the long tailed skua
Marine Ecology Progress Series, 2017Co-Authors: Rob Van Bemmelen, Raymond H G Klaassen, Sveinn Are Hanssen, Niels Martin Schmidt, Jannik Hansen, Johannes Lang, Benoit Sittler, Loic Bollache, Ingrid Tulp, Olivier GilgAbstract:Quantifying within- and between-individual variation in Animal Migration strategies is a first step towards our understanding of the ability of migrants to adjust to changes in the environment. We studied consistency (or, conversely, flexibility) in movement patterns at large (>1000 km) to meso-scales (100−1000 km) during the non-breeding season of the long-tailed skua Stercorarius longicaudus, a long-distance migratory Arctic seabird, using light-based geolocation. We obtained 97 annual tracks of 38 individuals and quantified similarity between routes. Overall, tracks of the same individual were generally within about 200 to 300 km of their previous year’s route, and more similar than tracks of different individuals. Some flexibility was observed during Migration, but individuals were faithful to their staging areas in the North Atlantic and in the Benguela Current off Namibia and South Africa. Over the course of the winter, an increasing number of individuals started to deviate—up to 5200 km—from the previous year’s route. Intriguingly, individuals could be highly consistent between 2 consecutive years and flexible between other years. Site-shifts in late winter seem to reflect responses to local conditions, but what promotes this larger flexibility remains unclear and requires further study. Our results show that individual long-tailed skuas are generally consistent in their itineraries, but can show considerable flexibility in some years. The flexibility in itineraries suggests that long-tailed skuas are able to adjust to environmental change, but the mechanisms leading to the observed within- and between-individual variation in movement patterns are still poorly understood.
Raymond H G Klaassen - One of the best experts on this subject based on the ideXlab platform.
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flexibility in otherwise consistent non breeding movements of a long distance migratory seabird the long tailed skua
Marine Ecology Progress Series, 2017Co-Authors: Rob Van Bemmelen, Raymond H G Klaassen, Sveinn Are Hanssen, Niels Martin Schmidt, Jannik Hansen, Johannes Lang, Benoit Sittler, Loic Bollache, Ingrid Tulp, Olivier GilgAbstract:Quantifying within- and between-individual variation in Animal Migration strategies is a first step towards our understanding of the ability of migrants to adjust to changes in the environment. We studied consistency (or, conversely, flexibility) in movement patterns at large (>1000 km) to meso-scales (100−1000 km) during the non-breeding season of the long-tailed skua Stercorarius longicaudus, a long-distance migratory Arctic seabird, using light-based geolocation. We obtained 97 annual tracks of 38 individuals and quantified similarity between routes. Overall, tracks of the same individual were generally within about 200 to 300 km of their previous year’s route, and more similar than tracks of different individuals. Some flexibility was observed during Migration, but individuals were faithful to their staging areas in the North Atlantic and in the Benguela Current off Namibia and South Africa. Over the course of the winter, an increasing number of individuals started to deviate—up to 5200 km—from the previous year’s route. Intriguingly, individuals could be highly consistent between 2 consecutive years and flexible between other years. Site-shifts in late winter seem to reflect responses to local conditions, but what promotes this larger flexibility remains unclear and requires further study. Our results show that individual long-tailed skuas are generally consistent in their itineraries, but can show considerable flexibility in some years. The flexibility in itineraries suggests that long-tailed skuas are able to adjust to environmental change, but the mechanisms leading to the observed within- and between-individual variation in movement patterns are still poorly understood.
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convergent patterns of long distance nocturnal Migration in noctuid moths and passerine birds
Proceedings of The Royal Society B: Biological Sciences, 2011Co-Authors: Thomas Alerstam, Johan Backman, Jason W Chapman, A D Smith, Hakan Karlsson, Cecilia Nilsson, D R Reynolds, Raymond H G Klaassen, Jane K HillAbstract:Vast numbers of insects and passerines achieve long-distance Migrations between summer and winter locations by undertaking high-altitude nocturnal flights. Insects such as noctuid moths fly relatively slowly in relation to the surrounding air, with airspeeds approximately one-third of that of passerines. Thus, it has been widely assumed that windborne insect migrants will have comparatively little control over their Migration speed and direction compared with migrant birds. We used radar to carry out the first comparative analyses of the flight behaviour and migratory strategies of insects and birds under nearly equivalent natural conditions. Contrary to expectations, noctuid moths attained almost identical ground speeds and travel directions compared with passerines, despite their very different flight powers and sensory capacities. Moths achieved fast travel speeds in seasonally appropriate Migration directions by exploiting favourably directed winds and selecting flight altitudes that coincided with the fastest air streams. By contrast, passerines were less selective of wind conditions, relying on self-powered flight in their seasonally preferred direction, often with little or no tailwind assistance. Our results demonstrate that noctuid moths and passerines show contrasting risk-prone and risk-averse migratory strategies in relation to wind. Comparative studies of the flight behaviours of distantly related taxa are critically important for understanding the evolution of Animal Migration strategies.