Blar i forfatter "Irvine, R. Justin"

Viser treff 1-3 av 3

    • Determinants of heart rate in Svalbard reindeer reveal mechanisms of seasonal energy management 

      Trondrud, Liv Monica; Pigeon, Gabriel; Albon, Steve; Arnold, Walter; Evans, Alina; Irvine, R. Justin; Król, Elżbieta; Ropstad, Erik; Stien, Audun; Veiberg, Vebjørn; Speakman, John R.; Loe, Leif Egil (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-28)
      Seasonal energetic challenges may constrain an animal's ability to respond to changing individual and environmental conditions. Here, we investigated variation in heart rate, a well-established proxy for metabolic rate, in Svalbard reindeer (Rangifer tarandus platyrhynchus), a species with strong seasonal changes in foraging and metabolic activity. In 19 adult females, we recorded heart rate, ...

    • Fat storage influences fasting endurance more than body size in an ungulate 

      Trondrud, Liv Monica; Pigeon, Gabriel; Król, Elżbieta; Albon, Steve; Evans, Alina; Arnold, Walter; Hambly, Catherine; Irvine, R. Justin; Ropstad, Erik; Stien, Audun; Veiberg, Vebjørn; Speakman, John R.; Loe, Leif Egil (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-26)
      <ol> <li>The fasting endurance hypothesis (FEH) predicts strong selection for large body size in mammals living in environments where food supply is interrupted over prolonged periods of time. The Arctic is a highly seasonal and food restricted environment, but contrary to predictions from the FEH, empirical evidence shows that Arctic mammals are often smaller than their temperate conspecifics. ...

    • Stress responses to repeated captures in a wild ungulate 

      Trondrud, Liv Monica; Ugland, Cassandra Regine; Ropstad, Erik; Loe, Leif Egil; Albon, Steve; Stien, Audun; Evans, Alina; Thorsby, Per Medbøe; Veiberg, Vebjørn; Irvine, R. Justin; Pigeon, Gabriel (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-29)
      While capture-mark-recapture studies provide essential individual-level data in ecology, repeated captures and handling may impact animal welfare and cause scientific bias. Evaluating the consequences of invasive methodologies should be an integral part of any study involving capture of live animals. We investigated short- and long-term stress responses to repeated captures within a winter on the ...