0000000000162302

AUTHOR

Jannik Hansen

0000-0002-2716-9928

showing 7 related works from this author

Effects of food abundance and early clutch predation on reproductive timing in a high Arctic shorebird exposed to advancements in arthropod abundance.

2016

12 pages; International audience; Climate change may influence the phenology of organisms unequally across trophic levels and thus lead to phenological mismatches between predators and prey. In cases where prey availability peaks before reproducing predators reach maximal prey demand, any negative fitness consequences would selectively favor resynchronization by earlier starts of the reproductive activities of the predators. At a study site in northeast Greenland, over a period of 17 years, the median emergence of the invertebrate prey of Sanderling Calidris alba advanced with 1.27 days per year. Yet, over the same period Sanderling did not advance hatching date. Thus, Sanderlings increasin…

0106 biological sciencesfood.ingredientBird migrationchick growthPOPULATION-SIZEBird migrationNEST PREDATIONBREEDING PHENOLOGYBiology010603 evolutionary biology01 natural sciencesphenology010605 ornithologyPredation[ SDV.EE ] Life Sciences [q-bio]/Ecology environmentnest survivalfoodCalidris alba (Pallastrophic mismatchAbundance (ecology)INTERANNUAL VARIATIONCHANGING CLIMATEtimingNORTHEAST GREENLANDEcology Evolution Behavior and SystematicsNature and Landscape ConservationTrophic levelOriginal ResearchCalidris albatrophic interactions[SDV.EE]Life Sciences [q-bio]/Ecology environmentCalidris alba (Pallas 1764) [sanderling][ SDE.BE ] Environmental Sciences/Biodiversity and EcologyCLIMATE-CHANGEEcologyPhenologyEcologyHatchingSNOW-COVER1764) [sanderling]trophic mismatch.PHENOLOGICAL MISMATCHESCalidrisclimate changeMIGRATORY BIRDSCalidris alba [sanderling][SDE.BE]Environmental Sciences/Biodiversity and EcologyArctic ecology
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Trans-equatorial migration routes, staging sites and wintering areas of a High-Arctic avian predator: the Long-tailed Skua (Stercorarius longicaudus).

2013

The Long-tailed Skua, a small (,300 g) Arctic-breeding predator and seabird, is a functionally very important component of the Arctic vertebrate communities in summer, but little is known about its migration and winter distribution. We used lightlevel geolocators to track the annual movements of eight adult birds breeding in north-east Greenland (n = 3) and Svalbard (n = 5). All birds wintered in the Southern Hemisphere (mean arrival-departure dates on wintering grounds: 24 October-21 March): five along the south-west coast of Africa (0–40uS, 0–15uE), in the productive Benguela upwelling, and three further south (30–40uS, 0–50uE), in an area extending into the south-west Indian Ocean. Diffe…

0106 biological sciencesTime FactorsGreenlandlcsh:MedicinehabitatBreeding01 natural sciencesSkuaSvalbardMarine ConservationStercorarius longicaudusOrnithologyFlywayOceansmovementsnorth-atlanticlcsh:ScienceAtlantic Oceanatlantic-ocean[SDV.EE]Life Sciences [q-bio]/Ecology environmentMultidisciplinarygeography.geographical_feature_categoryEcologyAnimal BehaviorbiologyArctic RegionsEcologyMarine EcologydynamicstrackingGeographygeolocationBiogeographyclimate-changeSeasonsSeabirdrevealspelagic seabird;atlantic-ocean;north-atlantic;climate-change;tracking;dynamics;geolocation;movements;reveals;habitatResearch Articlepelagic seabirdMarine Biology010603 evolutionary biology[ SDV.EE ] Life Sciences [q-bio]/Ecology environmentBirdsbiology.animalAnimals14. Life underwaterBiologySouthern Hemisphere[ SDE.BE ] Environmental Sciences/Biodiversity and Ecology010604 marine biology & hydrobiologylcsh:Rbiology.organism_classificationMarine and aquatic sciencesFisheryEarth sciencesArcticPredatory BehaviorUpwellingAnimal Migrationlcsh:Q[SDE.BE]Environmental Sciences/Biodiversity and EcologyOceanic basinZoology
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Behavioural responses of breeding arctic sandpipers to ground-surface temperature and primary productivity

2021

Most birds incubate their eggs, which requires time and energy at the expense of other activities. Birds generally have two incubation strategies: biparental where both mates cooperate in incubating eggs, and uniparental where a single parent incubates. In harsh and unpredictable environments, incubation is challenging due to high energetic demands and variable resource availability. We studied the relationships between the incubation behaviour of sandpipers (genus Calidris) and two environmental variables: temperature and a proxy of primary productivity (i.e. NDVI). We investigated how these relationships vary between incubation strategies and across species among strategies. We also stud…

Environmental EngineeringAves [Birds]010504 meteorology & atmospheric sciencesSandpiperNDVIZoologyIncubation recesses010501 environmental sciencesBiologyBreeding01 natural sciencesIncubation behaviourNesting BehaviorCharadriiformesincubation recessesEnvironmental ChemistrySmall speciesAnimalsEnvironmental conditionsWaste Management and DisposalIncubationPrimary productivity0105 earth and related environmental sciencesReproductive successArctic Regionsincubation strategyLag effectsGround surface temperatureTemperatureincubation behaviourShorebirdbiology.organism_classificationPollutionlag effectsenvironmental conditionsArcticshorebirdIncubation strategyGenus Calidris[SDE.BE]Environmental Sciences/Biodiversity and Ecology
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Flexibility in otherwise consistent non-breeding movements of a long-distance migratory seabird, the long-tailed skua

2017

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 en - vironment. 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 t…

ATLANTIC0106 biological sciencesEnvironmental changeIndividual consistency · Repeatability · Stercorarius longicaudus · Seabirds · Tracking · Non-breeding movements · Flexibility:Zoology and botany: 480 [VDP]CONSERVATIONMODELSTRANS-EQUATORIAL MIGRATIONAquatic Science010603 evolutionary biology01 natural sciencesSkuaStercorarius longicaudusOnderzoeksformatieOCEANALBATROSSESindividual consistencyDISPERSALbiology.animalRepeatability:Zoologiske og botaniske fag: 480 [VDP]Ecology Evolution Behavior and SystematicsEcologybiologyEcology[SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE]010604 marine biology & hydrobiologyFlexibility (personality)trackingbiology.organism_classificationTERNS STERNA-PARADISAEASeabirdsGeolocation[ SDV.BID.EVO ] Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE]GeographyArcticWildlife Ecology and ConservationStercorarius longicaudusNAVIGATIONWIASnon-breeding movementsBiological dispersalSeabirdFlexibilityBEHAVIOR
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Response of an arctic predator guild to collapsing lemming cycles

2012

6 pages; International audience; Alpine and arctic lemming populations appear to be highly sensitive to climate change, and when faced with warmer and shorter winters, their well-known high-amplitude population cycles may collapse. Being keystone species in tundra ecosystems, changed lemming dynamics may convey significant knock-on effects on trophically linked species. Here, we analyse long-term (1988-2010), community-wide monitoring data from two sites in high-arctic Greenland and document how a collapse in collared lemming cyclicity affects the population dynamics of the predator guild. Dramatic changes were observed in two highly specialized lemming predators: snowy owl and stoat. Follo…

Food ChainCarnivoraGreenlandPopulation DynamicsPopulationModels BiologicalGeneral Biochemistry Genetics and Molecular BiologyBirdsArcticDicrostonyx groenlandicusbiology.animal[ SDV.EE.IEO ] Life Sciences [q-bio]/Ecology environment/SymbiosisAnimalsArctic foxKeystone specieseducationPredatorResearch ArticlesGeneral Environmental Sciencepredator-prey interactioneducation.field_of_study[ SDE.BE ] Environmental Sciences/Biodiversity and EcologyGeneral Immunology and MicrobiologybiologyArctic RegionsArvicolinaeEcologyReproductionCollared lemmingcyclic population dynamicsGeneral Medicinebiology.organism_classificationclimate changeArcticGuildPopulation cycleSeasonsGeneral Agricultural and Biological Sciences
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First Observation of a Four-egg Clutch of Long-tailed Jaeger (Stercorarius longicaudus)

2015

5 pages; International audience; Long-tailed Jaegers (Stercorarius longicaudus) normally lay one or two eggs (rarely three), with a maximum of two eggs set by the existence of only two brood patches. Here, however, we present the first documentation of a clutch of four eggs in a Long-tailed Jaeger nest found at Zackenberg in northeastern Greenland.

0106 biological sciencesAvian clutch sizeclutch sizeEcologyEcologylemmingsGreenlandLong-tailed jaegerBiologybiology.organism_classification010603 evolutionary biology01 natural sciencesBrood010605 ornithologyStercorarius longicaudusNestStercorarius longicaudus[ SDV.BA.ZV ] Life Sciences [q-bio]/Animal biology/Vertebrate Zoology[SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate ZoologyAnimal Science and ZoologyClutch[SDV.BA.ZV] Life Sciences [q-bio]/Animal biology/Vertebrate ZoologyZackenbergEcology Evolution Behavior and Systematics
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Data from: Effects of food abundance and early clutch predation on reproductive timing in a high Arctic shorebird exposed to advancements in arthropo…

2017

Climate change may influence the phenology of organisms unequally across trophic levels and thus lead to phenological mismatches between predators and prey. In cases where prey availability peaks before reproducing predators reach maximal prey demand, any negative fitness consequences would selectively favor resynchronization by earlier starts of the reproductive activities of the predators. At a study site in northeast Greenland, over a period of 17 years, the median emergence of the invertebrate prey of Sanderling Calidris alba advanced with 1.27 days per year. Yet, over the same period Sanderling did not advance hatching date. Thus, Sanderlings increasingly hatched after their prey was m…

chick growthHoloceneDipteraSanderlingLife sciencesmedicine and health careHemipteranest survivalVulpes lagopustrophic mismatchAraneatimingMedicineclutch predationbird migrationmismatchCalidris alba
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