Now showing items 21-40 of 112

    • Demographic routes to variability and regulation in bird populations 

      Sæther, Bernt-Erik; Grøtan, Vidar; Engen, Steinar; Coulson, Tim; Grant, Peter R.; Visser, Marcel E.; Brommer, Jon E.; Grant, B. Rosemary; Gustafsson, Lars; Hatchwell, Ben J.; Jerstad, Kurt; Karell, Patrik; Pietiäinen, Hannu; Roulin, Alexandre; Røstad, Ole Wiggo; Weimerskirch, Henri (Journal article; Peer reviewed, 2016)
      There is large interspecific variation in the magnitude of population fluctuations, even among closely related species. The factors generating this variation are not well understood, primarily because of the challenges ...
    • Density-dependent selection and the maintenance of colour polymorphism in barn owls 

      Kvalnes, Thomas; Sæther, Bernt-Erik; Engen, Steinar; Roulin, Alexandre (Peer reviewed; Journal article, 2022)
      The capacity of natural selection to generate adaptive changes is (according to the fundamental theorem of natural selection) proportional to the additive genetic variance in fitness. In spite of its importance for development ...
    • Density‐dependent population dynamics of a high Arctic capital breeder, the barnacle goose 

      Layton-Matthews, Kate; Loonen, M. J. J. E; Hansen, Brage Bremset; Coste, Christophe Francois Daniel; Sæther, Bernt-Erik; Grøtan, Vidar (Journal article; Peer reviewed, 2019)
      Density regulation of the population growth rate occurs through negative feedbacks on underlying vital rates, in response to increasing population size. Here, we examine in a capital breeder how vital rates of different ...
    • Detecting climate signals in populations across life histories 

      Jenouvrier, Stéphanie; Long, Matthew C.; Coste, Christophe; Holland, Marika M.; Gamelon, Marlène; Yoccoz, Nigel; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)
      Climate impacts are not always easily discerned in wild populations as detecting climate change signals in populations is challenged by stochastic noise associated with natural climate variability, variability in biotic ...
    • Determinants of age at first reproduction and lifetime breeding success revealed by full paternity assignment in a male ungulate 

      Markussen, Stine Svalheim; Herfindal, Ivar; Loison, Anne; Solberg, Erling Johan; Haanes, Hallvard; Røed, Knut; Heim, Morten; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2018)
      Age at first reproduction is an important determinant of individual variation in reproductive success in ungulates, but few studies have examined its relationship with later fitness‐related traits in males. We used a ...
    • Disentangling the age-dependent causal pathways affecting multiple paternity in house sparrows 

      Søraker, Jørgen Skavdal (Master thesis, 2022)
      De drivende mekanismene bak fordelingen av polygami hos sosialt monogame fuglearter har fått mye oppmerksomhet de siste tiårene. Alder og morfologi, og særlig sekundære seksuelle trekk, har ofte blitt pekt på som viktige ...
    • Dispersal in a house sparrow metapopulation: An integrative case study of genetic assignment calibrated with ecological data and pedigree information 

      Saatoglu, Fikriye Dilan; Niskanen, Alina Katariina; Kuismin, Markku; Ranke, Peter Sjolte; Hagen, Ingerid Julie; Araya-Ajoy, Yimen; Kvalnes, Thomas; Pärn, Henrik; Rønning, Bernt; Ringsby, Thor Harald; Sæther, Bernt-Erik; Husby, Arild; Sillanpää, Mikko J.; Jensen, Henrik (Peer reviewed; Journal article, 2021)
      Dispersal has a crucial role determining ecoevolutionary dynamics through both gene flow and population size regulation. However, to study dispersal and its consequences, one must distinguish immigrants from residents. ...
    • DNA Metabarcoding Diet Analysis of Water Vole (Arvicola amphibius) in Northern Norway 

      Østby, Nina (Master thesis, 2019)
      Studier og kunnskap om hvilke faktorer som påvirker populasjonsdynamikk er svært viktig i økologi. Det gir viktig informasjon som er nyttig for blant annet bevaring av biodiversitet i en tid der den trues av globale ...
    • Does multiple paternity explain phenotypic variation among offspring in wild boar? 

      Gamelon, Marlène; Gayet, Thibault; Baubet, Eric; Devillard, Sébastien; Say, Ludovic; Brandt, Serge; Pelabon, Christophe; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2018)
      During pregnancy, littermates compete to extract maternal resources from the placenta. Unequal extraction of resources leads to developmental differences among offspring and thus within-litter variation in offspring mass. ...
    • Eco-evolutionary feedbacks - theoretical models and perspectives 

      Govaert, Lynn; Fronhofer, Emanuel A.; Lion, Sébastien; Eizaguirre, Christophe; Bonte, Dries; Egas, Martijn; Hendry, Andrew P.; Martins, Ayana de Brito; Melian, Carlos J.; Raeymaekers, Joost A. M.; Ratikainen, Irja Ida; Sæther, Bernt-Erik; Schweitzer, Jennifer A.; Matthews, Blake (Journal article; Peer reviewed, 2018)
      Theoretical models pertaining to feedbacks between ecological and evolutionary processes are prevalent in multiple biological fields. An integrative overview is currently lacking, due to little crosstalk between the fields ...
    • Ecological dynamics and large scale phenotypic differentiation in density-dependent populations 

      Engen, Steinar; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2019)
      Spatial differentiation of phenotypes is assumed to be determined by a combination of fluctuating selection producing adaptations to the local environment and a homogenizing effect of migration. We present a model with ...
    • Effective size of density dependent populations in fluctuating environments 

      Myhre, Ane Marlene (Doctoral theses at NTNU;2017:156, Doctoral thesis, 2017)
      Knowledge of the effective size of populations, Ne, and the ratio of effective population size to the size of the mature population Ne/N, provide important information of the genetic diversity and fitness of populations. ...
    • Effects of Climate and Animal Density on Adult Sex Ratio Variation in a Large Herbivore 

      Peeters, Bart (Master thesis, 2014)
      Adult sex ratio is often biased in natural populations, and its variation is known to influence different demographic components at the population level. The causes of variation in adult sex ratio remain, however, poorly ...
    • Effects of inbreeding on fitness-related traits in a small isolated moose population 

      Haanes, Hallvard; Markussen, Stine Svalheim; Herfindal, Ivar; Røed, Knut H.; Solberg, Erling Johan; Heim, Morten; Midthjell, Liv; Sæther, Bernt-Erik (Journal article; Peer reviewed, 2013)
      Inbreeding can affect fitness-related traits at different life history stages and may interact with environmental variation to induce even larger effects. We used genetic parentage assignment based on 22 microsatellite ...
    • Effects of local density dependence and temperature on the spatial synchrony of marine fish populations 

      Marquez, Jonatan; Herfindal, Ivar; Sæther, Bernt-Erik; Aanes, Sondre; Salthaug, Are; Lee, Aline Magdalena (Peer reviewed; Journal article, 2023)
      Disentangling empirically the many processes affecting spatial population synchrony is a challenge in population ecology. Two processes that could have major effects on the spatial synchrony of wild population dynamics are ...
    • Effects of population characteristics and structure on estimates of effective population size in a house sparrow metapopulation 

      Baalsrud, Helle Tessand; Sæther, Bernt-Erik; Hagen, Ingerid Julie; Myhre, Ane Marlene; Ringsby, Thor Harald; Pärn, Henrik; Jensen, Henrik (Journal article, 2014)
      Effective population size (Ne) is a key parameter to understand evolutionary processes and the viability of endangered populations as it determines the rate of genetic drift and inbreeding. Low Ne can lead to inbreeding ...
    • Effects of pulsed resources on the dynamics of seed consumer populations: a comparative demographic study in wild boar 

      Gamelon, Marlène; Touzot, Laura; Baubet, Eric; Cachelou, Jessica; Focardi, Stefano; Franzetti, Barbara; Nivois, Eveline; Veylit, Lara; Sæther, Bernt-Erik (Peer reviewed; Journal article, 2021)
      Mast seeding is a well-known example of pulsed resources in terrestrial ecosystems. Despite the large literature available so far on the effects of mast seeding on the dynamics of seed consumer populations, it remains ...
    • Elgen i Norge sett med jegerøyne. En analyse av jaktmaterialet fra overvå-kingsprogrammet for elg og det samlede sett elg-materialet for perioden 1966-2004 

      Solberg, Erling Johan; Rolandsen, Christer Moe; Heim, Morten; Grøtan, Vidar; Garel, Mathieu; Sæther, Bernt-Erik; Nilsen, Erlend Birkeland; Austrheim, Gunnar; Herfindal, Ivar (NINA rapport;125, Research report, 2006)
      Elgen er en viktig utmarksressurs i Norge. Som et ledd i overvåkingen av denne ressursen be-nyttes elgjegere til å samle inn forskjellig type data fra observerte og felte elg under jakta hvert år. Dette materialet er i ...
    • Elgens genetiske struktur i Norge 

      Solberg, Erling Johan; Røed, Knut H.; Flagstad, Øystein; Sæther, Bernt-Erik; Heim, Morten; Andersen, Reidar; Rolandsen, Christer Moe (NINA Rapport;467, Research report, 2009)
      Elgen er en viktig naturressurs i Norge med stor økonomisk og rekreasjonsmessig betydning. Til tross for dette vet vi lite om elgens genetiske variasjon, og således evnen den norske elgen har til å takle forandringer i ...
    • Elgundersøkelsene i Nord-Trøndelag, Bindal og Rissa 2005 - 2010. Sluttrapport 

      Rolandsen, Christer Moe; Solberg, Erling Johan; Bjørneraas, Kari; Heim, Morten; Van Moorter, Bram; Herfindal, Ivar; Garel, Mathieu; Pedersen, Paul Harald; Sæther, Bernt-Erik; Lykkja, Odd N.; Os, Øystein (NINA rapport;588, Research report, 2010)
      Rapporten beskriver resultatene fra Elgundersøkelsene i Nord-Trøndelag, Bindal og Rissa. Det overordnede målet har vært å øke den generelle kunnskapen om elgen i området, og gjennom dette bidra til å styrke det faglige ...