Browsing NTNU Open by Author "Jensen, Henrik"
Now showing items 1-20 of 65
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A battle of the mountains: Intraguild competition between arctic fox Vulpes lagopus and red fox Vulpes vulpes
Grevskott, Ragnhild Thorseth (Master thesis, 2019)Fjellreven (Vulpes lagopus) er en truet art i Fennoskandia. Konkurranse med rødreven (Vulpes vulpes) er regnet som en av hovedtruslene for fjellrevens utbredelse. Flere bevaringstiltak har blitt satt i gang for å redde ... -
A Continuous-Time, Discrete-Space Statistical Model for Estimating Dispersal Rate Applied to a Population of House Sparrows (Passer Domnesticus) in Northern Norway
Drahus, Kristin Mathilde (Master thesis, 2015)How individuals move and interact with each other is a complex matter. Even so, the knowledge of how such movements and interactions happen is important to understand in order to be able to keep genetic variation and ... -
Acclimation Potential to a Future Ocean Acidification Scenario in the Key Copepod Species Calanus finmarchicus: - with emphasis on the genetic contribution to the acclimation response
Aase, Marit (Master thesis, 2014)Ocean acidification, as a result of the increased concentration of carbon dioxide in the ocean, poses a threat towards marine ecosystems through lowered pH and altered seawater chemistry. The marine copepod Calanus ... -
Animal Models and Integrated Nested Laplace Approximations
Holand, Anna Marie; Steinsland, Ingelin; Martino, Sara; Jensen, Henrik (Journal article; Peer reviewed, 2013)Animal models are generalized linear mixed models used in evolutionary biology and animal breeding to identify the genetic part of traits. Integrated Nested Laplace Approximation (INLA) is a methodology for making fast, ... -
Animal models with group-specific additive genetic variances: extending genetic group models
Muff, Stefanie; Niskanen, Alina Katariina; Saatoglu, Dilan; Keller, Lukas; Jensen, Henrik (Journal article; Peer reviewed, 2019)Background The animal model is a key tool in quantitative genetics and has been used extensively to estimate fundamental parameters, such as additive genetic variance or heritability. An implicit assumption of animal ... -
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 ... -
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 ... -
Covarying Behaviours and Innovation in a House Sparrow Metapopulation - Implications for Social Foraging
Hammerås, John (Master thesis, 2016)Individuals in populations of many species have been found to differ consistently in suites of correlating behavioural measures. These phenomena appear to be heritable and subject to selection, thus making it as important ... -
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 ... -
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 ... -
Diversity, Loss, and Gain of Malaria Parasites in a Globally Invasive Bird
Marzal, Alfonso; Ricklefs, Robert E.; Valkiunas, Gediminas; Albayrak, Tamer; Arriero, Elena; Bonneaud, Camille; Czirjak, Gabor A.; Ewen, John; Hellgren, Olof; Horakova, Dita; Iezhova, Tatjana A.; Jensen, Henrik; Krizanauskiene, Asta; Lima, Marcos R.; de Lope, Florentino; Magnussen, Eydfinn; Martin, Lynn B.; Møller, Anders P.; Palinauskas, Vaidas; Pap, Peter L.; Perez-Tris, Javier; Sehgal, Ravinder N. M.; Soler, Manuel; Szöllösi, Eszter; Westerdahl, Helena; Zetindjiev, Pavel; Bensch, Staffan (Journal article; Peer reviewed, 2011)Invasive species can displace natives, and thus identifying the traits that make aliens successful is crucial for predicting and preventing biodiversity loss. Pathogens may play an important role in the invasive process, ... -
Drivers of change in meso-carnivore distributions in a northern ecosystem
Rød-Eriksen, Lars (Doctoral theses at NTNU;2020:182, Doctoral thesis, 2020)Species have been subject to major perturbations in recent times, such as over-harvest, habitat loss and climate change, affecting their distribution and abundance. Alpine and arctic tundra ecosystems are particularly ... -
The Effect of Management on Effective Population Size in the Arctic Fox (Vulpes lagopus) Metapopulation in Scandinavia.
Andersskog, Ida Pernille Øystese (Master thesis, 2017)Estimates of effective population size (Ne) may provide insight to patterns of changes in allele frequencies and heterozygosity in a population. Furthermore, by estimating Ne, one can predict future changes in genetic ... -
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 and recovery of larvae of the cold-water coral Lophelia pertusa (Desmophyllum pertusum) exposed to suspended bentonite, barite and drill cuttings
Järnegren, Nina Johanna; Brooke, Sandra; Jensen, Henrik (Peer reviewed; Journal article, 2020)Fossil fuel drilling operations create sediment plumes and release waste materials into the ocean. These operations sometimes occur close to sensitive marine ecosystems, such as cold-water corals. While there have been ... -
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 Variation in Egg Size on Offspring Fitness in Populations of House Sparrow (Passer domesticus)
Røberg, Anja Ås (Master thesis, 2015)1. Egg size represents an important life-history trait, which may have effects on the fitness of offspring. The effect of variation in egg size on offspring fitness has been studied within many taxa, but there is still a ... -
Endoparasite infection has both short- and long-term negative effects on reproductive success of female house sparrows, as revealed by faecal parasitic egg counts
Holand, Håkon; Jensen, Henrik; Tufto, Jarle; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article; Peer reviewed, 2015)Parasites have the potential to severely reduce host reproductive success. However, the effects of endoparasites on reproductive success have not received the same amount of attention as the effects of parasites on host ... -
Factors Affecting Juvenile Movement in a House Sparrow Metapopulation
Myhre, Ane Marlene (Master thesis, 2012)Dispersal propensity can vary considerably between individuals in a population. Understanding which individuals disperse- and under what circumstances these individuals disperse is valuable for conservation. Factors ... -
Fitness Consequences of Intra-Island dispersal in a House Sparrow (Passer domesticus) Population
Hansen, Ann-Katrine Esp (Master thesis, 2012)Dispersing individuals have the ability to link fragmented populations to each other, and influence a wide range of ecological and evolutionary processes. Understanding the fitness differences between resident and dispersing ...