Browsing NTNU Open by Author "Sæther, Bernt-Erik"

Now showing items 1-20 of 112

    • Accounting for interspecific competition and age structure in demographic analyses of density dependence improves predictions of fluctuations in population size 

      Gamelon, Marlène; Vriend, Stefan; Engen, Steinar; Adriaensen, Frank; Dhondt, A.A.; Evans, Simon R.; Matthysen, Erik; Sheldon, Ben C.; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2019)
      Understanding species coexistence has long been a major goal of ecology. Coexistence theory for two competing species posits that intraspecific density dependence should be stronger than interspecific density dependence. ...

    • Age-dependent patterns of spatial autocorrelation in fish populations 

      Marquez, Jonatan; Sæther, Bernt-Erik; Aanes, Sondre; Engen, Steinar; Salthaug, Are; Lee, Aline Magdalena (Journal article; Peer reviewed, 2021)
      The degree of spatial autocorrelation in population fluctuations increases with dispersal and geographical covariation in the environment, and decreases with strength of density dependence. Because the effects of these ...

    • An integrated population model for a long-lived ungulate: more efficient data use with Bayesian methods 

      Lee, Aline Magdalena; Bjørkvoll, Eirin Marie; Hansen, Brage Bremset; Albon, Steve D.; Stien, Audun; Sæther, Bernt-Erik; Engen, Steinar; Veiberg, Vebjørn; Loe, Leif Egil; Grøtan, Vidar (Journal article, 2015)
      We develop an integrated population model for Svalbard reindeer Rangifer tarandus platyrhynchus, and demonstrate how this type of model can be used to extract more information from the data and separate different sources ...

    • Artificial size selection experiment reveals telomere length dynamics and fitness consequences in a wild passerine 

      Pepke, Michael Le; Kvalnes, Thomas; Rønning, Bernt; Jensen, Henrik; Boner, Winnie; Sæther, Bernt-Erik; Monaghan, Pat; Ringsby, Thor Harald (Peer reviewed; Journal article, 2022)
      Telomere dynamics could underlie life-history trade-offs among growth, size and longevity, but our ability to quantify such processes in natural, unmanipulated populations is limited. We investigated how 4 years of artificial ...

    • Causes and consequences of intersexual life history variation in a harvested herbivore population 

      Markussen, Stine Svalheim (Doctoral theses at NTNU;2018:246, Doctoral thesis, 2018)
      Et individ sin livshistorie er de stadiene knytt til reproduksjon og overlevelse som individet gjennomgår i løpet av livet. Variasjon i livshistorietrekk mellom individ er både et resultat av, og grunnlaget for evolusjonære ...

    • Causes and consequences of variation in early-life telomere length in a bird metapopulation 

      Pepke, Michael Le; Kvalnes, Thomas; Ranke, Peter Sjolte; Araya-Ajoy, Yimen; Wright, Jonathan; Sæther, Bernt-Erik; Jensen, Henrik; Ringsby, Thor Harald (Peer reviewed; Journal article, 2022)
      Environmental conditions during early-life development can have lasting effects shaping individual heterogeneity in fitness and fitness-related traits. The length of telomeres, the DNA sequences protecting chromosome ends, ...

    • Causes and consequences of variation in resource use and social structure in ungulates 

      Ofstad, Endre Grüner (Doktoravhandlinger ved NTNU;2019:33, Doctoral thesis, 2019)
      Arter som opplever varierende miljø og begrensede ressurser må foreta en avveining blant alternative atferder for å maksimere overlevelse og reproduksjon. En økt forståelse av innflytelsen av miljø og individkarakteristikker ...

    • Characterizing morphological (co)variation using structural equation models: Body size, allometric relationships and evolvability in a house sparrow metapopulation 

      Araya-Ajoy, Yimen; Ranke, Peter Sjolte; Kvalnes, Thomas; Rønning, Bernt; Holand, Håkon; Myhre, Ane Marlene; Pärn, Henrik; Jensen, Henrik; Ringsby, Thor Harald; Sæther, Bernt-Erik; Wright, Jonathan (Peer reviewed; Journal article, 2019)
      Body size plays a key role in the ecology and evolution of all organisms. Therefore, quantifying the sources of morphological (co)variation, dependent and independent of body size, is of key importance when trying to ...

    • Climate and density-dependence cause changes in adult sex ratio in a large Arctic herbivore 

      Peeters, Bart; Veiberg, Vebjørn; Pedersen, Åshild Ønvik; Stien, Audun; Irvine, Robert Justin; Aanes, Ronny; Sæther, Bernt-Erik; Strand, Olav; Hansen, Brage Bremset (Journal article; Peer reviewed, 2017)
      Variation in adult sex ratio (ASR) affects population demography and dynamics of large mammals. The mechanisms behind this variation are largely unclear, but may be partly related to climatic drivers and density dependence ...

    • Climate Events Synchronize the Dynamics of a Resident Vertebrate Community in the High Arctic 

      Hansen, Brage Bremset; Grøtan, Vidar; Aanes, Ronny; Sæther, Bernt-Erik; Stien, Audun; Fuglei, Eva; Ims, Rolf Anker; Yoccoz, Nigel; Pedersen, Åshild Ønvik (Journal article; Peer reviewed, 2013)
      Recently accumulated evidence has documented a climate impact on the demography and dynamics of single species, yet the impact at the community level is poorly understood. Here, we show that in Svalbard in the high Arctic, ...

    • Connecting the data landscape of long‐term ecological studies: The SPI‐Birds data hub 

      Culina, Antica; Adriaensen, Frank; Bailey, Liam D.; Burgess, Malcolm; Charmantier, Anne; Cole, Ella F; Eeva, Tapio; Matthysen, Erik; Nater, Chloe Rebecca; Sheldon, Ben C.; Sæther, Bernt-Erik; Vriend, Stefan J.G.; Zajkova, Zuzana; Adamik, Peter; Aplin, Lucy M.; Angulo, Elena; Artemyev, Alexandr; Barba, Emilio; Barišić, Sanja; Belda, Eduardo; Bilgin, Cemal Can; Bleu, Josefa; Both, Christiaan; Bouwhuis, Sandra; Branston, Claire J.; Broggi, Juli; Burke, Terry; Bushuev, Andrey; Camacho, Carlos; Campobello, Daniela; Canal, David; Cantarero, Alejandro; Caro, Samuel P.; Chaine, Alexis; Cauchoix, Maxime; Cichoń, Mariusz; Ćiković, Davor; Cusimano, Camillo A.; Deimel, Caroline; Dhondt, André A.; Dingemanse, Niels J.; Doligez, Blandine; Doutrelant, Claire; Drobniak, Szymon M.; Dubiec, Anna; Eens, Marcel; Erikstad, Kjell E; Espín, Silvia; Farine, Damien R.; Mennerat, Adele (Peer reviewed; Journal article, 2020)
      The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long‐term studies of individually marked animals are not an ...

    • Controlling for P-value inflation in allele frequency change in experimental evolution and artificial selection experiments 

      Kemppainen, Petri; Rønning, Bernt; Kvalnes, Thomas; Hagen, Ingerid Julie; Ringsby, Thor Harald; Billing, Anna Maria; Pärn, Henrik; Lien, Sigbjørn; Husby, Arild; Sæther, Bernt-Erik; Jensen, Henrik (Journal article; Peer reviewed, 2017)
      Experimental evolution studies can be used to explore genomic response to artificial and natural selection. In such studies, loci that display larger allele frequency change than expected by genetic drift alone are assumed ...

    • Cost of migration in moose (Alces alces) with regard to mortality risk and locomotion 

      Tollefsen, Zandra Margareta (Master thesis, 2011)
      Summary1. Migration is present in all animal taxa and is defined as a periodic movement pattern between given ranges. Migratory individuals generally move more directional and with higher speed than stationary individuals ...

    • Decomposing demographic contributions to the effective population size with moose as a case study 

      Lee, Aline Magdalena; Myhre, Ane Marlene; Markussen, Stine Svalheim; Engen, Steinar; Solberg, Erling Johan; Haanes, Hallvard; Røed, Knut; Herfindal, Ivar; Heim, Morten; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2020)
      Levels of random genetic drift are influenced by demographic factors, such as mating system, sex ratio and age structure. The effective population size (N e) is a useful measure for quantifying genetic drift. Evaluating ...

    • Decomposing demographic contributions to the effective population size with moose as a case study 

      Lee, Aline Magdalena; Svalheim Markussen, Stine; Engen, Steinar; Solberg, Erling Johan; Haanes, Hallvard; Røed, Knut H.; Herfindal, Ivar; Heim, Morten; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2020)
      Levels of random genetic drift are influenced by demographic factors, such as mating system, sex ratio and age structure. The effective population size (Ne) is a useful measure for quantifying genetic drift. Evaluating ...

    • Demographic and genetic consequences of dispersal in house sparrows 

      Ranke, Peter Sjolte (Doctoral theses at NTNU;2019:24, Doctoral thesis, 2019)
      The importance of dispersal in population dynamics is widely acknowledged. Key to understand population consequences of dispersal is by quantifying the demographic and genetic contribution from dispersers. The influence ...

    • The Demographic buffering hypothesis: Evidence and challenges 

      Hilde, Christoffer Høyvik; Gamelon, Marlène; Sæther, Bernt-Erik; Gaillard, Jean-Michel; Yoccoz, Nigel; Pelabon, Christophe (Peer reviewed; Journal article, 2020)
      In (st)age-structured populations, the long-run population growth rate is negatively affected by temporal variation in vital rates. In most cases, natural selection should minimize temporal variation in the vital rates to ...

    • Demographic buffering of life histories? Implications of the choice of measurement scale 

      Bjørkvoll, Eirin Marie; Lee, Aline Magdalena; Grøtan, Vidar; Sæther, Bernt-Erik; Stien, Audun; Engen, Steinar; Albon, Steve D.; Loe, Leif Egil; Hansen, Brage Bremset (Journal article; Peer reviewed, 2016)
      Life-history theory predicts that the vital rates that influence population growth the most should be buffered against environmental fluctuations due to selection for reduced variation. However, it remains unclear whether ...

    • Demographic consequences of harvesting: a case study from a small and isolated moose population 

      Herfindal, Ivar; Lee, Aline Magdalena; Hamel, Sandra; Solberg, Erling Johan; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)
      ABSTRACT: Harvesting can have a substantial impact on population dynamics and individual performance in wild populations. While the direct consequences of harvest on individual survival and population growth rate are often ...

    • Demographic influences of translocated individuals on a resident population of house sparrows 

      Ranke, Peter Sjolte; Skjelseth, Sigrun; Pärn, Henrik; Herfindal, Ivar; Borg Pedersen, Åsa Alexandra; Stokke, Bård Gunnar; Kvalnes, Thomas; Ringsby, Thor Harald; Sæther, Bernt-Erik; Jensen, Henrik (Journal article; Peer reviewed, 2017)
      Translocation of individuals from source populations to augment small populations facing risk of extinction is an important conservation tool. Here we examine sex-specific differences between resident and translocated house ...