Browsing NTNU Open by Author "Ratikainen, Irja Ida"
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A dynamic state modelling approach to partial migration in brown trout
Solvåg, Christianne Dalsbotten (Master thesis, 2022)Partiell migrasjon, fenomenet der ein populasjon har både individ som migrerer og individ som let vere, er observert i store delar av dyreriket. Mekanismane bak kan vere komplekse, og kan inkludere både genetikk og miljø ... -
Adaptive responses to environmental stochasticity on different evolutionary time-scales
Haaland, Thomas Ray (Doctoral theses at NTNU;2019:154, Doctoral thesis, 2019)All life on earth needs to cope with unpredictable (stochastic) environmental variation, and has evolved to do so. However, environmental conditions are currently changing not only in their average levels (e.g. warmer, ... -
An experimental test of optimal sampling behaviour in Siberian jays (Perisoreus infaustus)
Sødal, Liv Randi Henøen (Master thesis, 2010)Optimal foraging models tend to assume that animals have perfect information. However, the world is constantly changing, and so it is likely that animals benefit from gathering better knowledge much of the time. Therefore, ... -
An investigation into animal personality in early benthic phase European lobster (Homarus gammarus)
Gilbreath, Ashley Ann (Master thesis, 2016)Consistent individual differences in behavior, also known as animal personality, have been described across a wide range of taxa. In this study, evidence for animal personality was investigated in the European lobster, an ... -
Bet-hedging across generations can affect the evolution of variance-sensitive strategies within generations
Haaland, Thomas; Wright, Jonathan; Ratikainen, Irja Ida (Journal article; Peer reviewed, 2019)In order to understand how organisms cope with ongoing changes in environmental variability, it is necessary to consider multiple adaptations to environmental uncertainty on different time scales. Conservative bet-hedging ... -
Characteristics determining host suitability for a generalist parasite
Stokke, Bård Gunnar; Ratikainen, Irja Ida; Moksnes, Arne; Røskaft, Eivin; Schulze-Hagen, Karl; Leech, David I.; Møller, Anders pape; Fossøy, Frode (Journal article; Peer reviewed, 2018)Host quality is critical for parasites. The common cuckoo Cuculus canorus is a generalist avian brood parasite, but individual females show strong preference for a specific host species. Here, we use three extensive datasets ... -
Differential allocation of parental investment and the trade-off between size and number of offspring
Ratikainen, Irja Ida; Haaland, Thomas; Wright, Jonathan (Journal article; Peer reviewed, 2018)When parents decide how much to invest in current versus future offspring and how many offspring to divide their current investments between, the optimal decision can be affected by the quality of their partner. This ... -
Differential allocation revisited: When should mate quality affect parental investment?
Haaland, Thomas; Wright, Jonathan; Kuijper, Bram; Ratikainen, Irja Ida (Journal article; Peer reviewed, 2017)Differential allocation (DA) is the adaptive adjustment of reproductive investment (up or down) according to partner quality. A lack of theoretical treatments has led to some confusion in the interpretation of DA in the ... -
Do the invasive fish species round goby (Neogobius melanostomus) and the native fish species viviparous eelpout (Zoarces viviparus) compete for shelter?
Gullichsen, Thea Bjørnsdatter (Master thesis, 2019)Introduksjon av arter forårsaket av mennesker har økt enormt over de siste tiårene, med økende transport og handel på tvers av landegrenser. Etablering av invasive arter i et nytt miljø kan resultere i drastiske endringer ... -
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 ... -
Environmental change and the rate of phenotypic plasticity
Burton, Tim; Ratikainen, Irja Ida; Einum, Sigurd (Peer reviewed; Journal article, 2022)With rapid and less predictable environmental change emerging as the ‘new norm’, understanding how individuals tolerate environmental stress via plastic, often reversible changes to the phenotype (i.e., reversible phenotypic ... -
Foraging in a variable world: Adaptations to stochasticity
Ratikainen, Irja Ida (Doktoravhandlinger ved NTNU, 1503-8181; 2012:70, Doctoral thesis, 2012) -
How to quantify thermal acclimation capacity?
Einum, Sigurd; Ratikainen, Irja Ida; Wright, Jonathan; Pelabon, Christophe; Bech, Claus; Jutfelt, Fredrik; Stawski, Clare; Burton, Tim (Peer reviewed; Journal article, 2019)The capacity of organisms to acclimate will influence their ability to cope with ongoing global changes in thermal regimes. Here we highlight methodological issues associated with recent attempts to quantify variation in ... -
Individual and temporal variation in movement patterns of wild alpine reindeer and implications for disease management
Hjermann, Tilde Katrina Slotte; Herfindal, Ivar; Ratikainen, Irja Ida; Strand, Olav; Rauset, Geir Rune (Journal article; Peer reviewed, 2024)Animal behaviour is important for prevalence and outbreaks of infectious diseases, for instance by affecting individual interactions. Increasing the knowledge of individual movement patterns can provide better insight into ... -
“Individual Variation in Site Fidelity of Moose”
Dahal, Pooja (Master thesis, 2023)1. Site fidelity, the tendency of animals to return to the same areas within or among the years can contribute to maximizing individual fitness by improving survival and reproduction. Seasonal and temporal variation of ... -
An investigation into animal personality in early benthic phase European lobster (Homarus gammarus)
Gilbreath, Ashley Ann (Master thesis, 2016)Consistent individual differences in behavior, also known as animal personality, have been described across a wide range of taxa. In this study, evidence for animal personality was investigated in the European lobster, an ... -
Modelling activity of terrestrial insects in different temperature and water availability scenarios
Gilberg, Line Skåland (Master thesis, 2022)Klimaendringer er forventet å endre de ytre omgivelsene til levende organismer. For terrestriske ektoterme dyr vil den kombinerte effekten av høyere temperaturer og endrede nedbørsmøster kunne utgjøre en fundamental ... -
Modelling thermal preference and fitness consequences in scenarios of decreasing temperature predictability
Olsen, Tora (Master thesis, 2019)Klimaendringane er venta å auke snittemperaturen, men også variasjon og føreseielegheit i temperatur. Nøyaktige predikasjonar av framtidig førekomst og foredling av artar må difor ta omsyn også til desse faktorane. Fordi ... -
Plant environmental memory: implications, mechanisms and opportunities for plant scientists and beyond
Auge, Gabriela; Hankofer, Valentin; Groth, Martin; Antoniou-Kourounioti, Rea; Ratikainen, Irja Ida; Lampei, Christian (Peer reviewed; Journal article, 2023)Plants are extremely plastic organisms. They continuously receive and integrate environmental information and adjust their growth and development to favour fitness and survival. When this integration of information affects ... -
Round goby (Neogobius melanostomus) - a potential threat to northern pike (Esox lucius) recruitment in the Swedish Baltic Sea coastline?
Andresen, Katrine (Master thesis, 2019)Invasive arter er en stor trussel mot akvatisk biodiversitet verden over, da de fører til sterke økologiske virkninger i akvatiske økosystemer. En svært suksessfull invasiv fiskeart er svartmunnet kutling (Neogobius ...