• Congruent responses to weather variability in high arctic herbivores 

      Stien, Audun; Ims, Rolf Anker; Albon, Steve D.; Fuglei, Eva; Irvine, R.J.; Ropstad, Erik; Halvorsen, Odd; Langvatn, Rolf; Loe, Leif Egil; Veiberg, Vebjørn; Yoccoz, Nigel (Journal article; Tidsskriftartikkel; Peer reviewed, 2012-09-26)
      Assessing the role of weather in the dynamics of wildlife populations is a pressing task in the face of rapid environmental change. Rodents and ruminants are abundant herbivore species in most Arctic ecosystems, many of which are experiencing particularly rapid climate change. Their different life-history characteristics, with the exception of their trophic position, suggest that they should show ...
    • Context-dependent fitness costs of reproduction despite stable body mass costs in an Arctic herbivore 

      Pigeon, Gabriel; Albon, Steve; Loe, Leif Egil; Bischof, Richard; Bonenfant, Christophe; Ropstad, Erik; Veiberg, Vebjørn; Stien, Audun (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-20)
      1.The cost of reproduction on demographic rates is often assumed to operate through changing body condition. Several studies have found that reproduction depresses body mass more if the current conditions are severe, such as high population densities or adverse weather, than under benign environmental conditions. However, few studies have investigated the association between the fitness components ...
    • 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, ...
    • Don't go chasing the ghosts of the past: habitat selection and site fidelity during calving in an Arctic ungulate 

      Paulsen, Ingrid M.; Soininen, Eeva M; Ravolainen, Virve; Loe, Leif Egil; Hansen, Brage Bremset; Irvine, Justin R; Stien, Audun; Ropstad, Erik; Veiberg, Vebjørn; Fuglei, Eva; Pedersen, Åshild Ønvik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-01)
      Predator avoidance and food availability are both factors known to influence habitat selection and site fidelity around calving in caribou and reindeer. Here, we assess habitat selection and site fidelity during the calving period in the solitary, Arctic Svalbard reindeer Rangifer tarandus platyrhynchus, which is subject to limited predation risk and human disturbance. In this largely predator-free ...
    • 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. ...
    • High seasonal overlap in habitat suitability in a nonmigratory High Arctic ungulate 

      Pedersen, Åshild Ønvik; Soininen, Eeva M; Hansen, Brage Bremset; Le Moullec, Mathilde; Loe, Leif Egil; Paulsen, I.M.G.; Eischeid, Isabell; Karlsen, Stein Rune; Ropstad, Erik; Stien, Audun; Tarroux, Arnaud; Tømmervik, Hans; Ravolainen, Virve (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-26)
      Understanding drivers of space use and habitat selection is essential for management and conservation, especially under rapid environmental change. Here, we develop summer and winter habitat suitability models for the endemic wild Svalbard reindeer (Rangifer tarandus platyrhynchus). The High Arctic Svalbard tundra is currently subject to the fastest temperature increases on Earth, and reindeer ...
    • The neglected season: Warmer autumns counteract harsher winters and promote population growth in Arctic reindeer 

      Loe, Leif Egil; Liston, Glen E.; Pigeon, Gabriel; Barker, Kristin; Horvitz, Nir; Stien, Audun; Forchhammer, Mads C.; Getz, Wayne M.; Irvine, Robert Justin; Lee, Aline Magdalena; Movik, Lars K.; Mysterud, Atle; Pedersen, Åshild Ønvik; Reinking, Adele K.; Ropstad, Erik; Trondrud, Liv Monica; Tveraa, Torkild; Veiberg, Vebjørn; Hansen, Brage Bremset; Albon, Steve D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-24)
      Arctic ungulates are experiencing the most rapid climate warming on Earth. While concerns have been raised that more frequent icing events may cause die‐offs, and earlier springs may generate a trophic mismatch in phenology, the effects of warming autumns have been largely neglected. We used 25 years of individual‐based data from a growing population of wild Svalbard reindeer, to test how warmer ...
    • Perfluoroalkyl acids potentiate glutamate excitotoxicity in rat cerebellar granule neurons 

      Berntsen, Hanne Friis; Moldes-Anaya, Angel; Bjørklund, Cesilie Granum; Ragazzi, Lorenzo; Haug, Trude M; Strandabø, Rønnaug; Verhaegen, Steven; Paulsen, Ragnhild Elisabeth; Ropstad, Erik; Tasker, Andrew (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-04)
      Perfluoroalkyl acids (PFAAs) are persistent man-made chemicals, ubiquitous in nature and present in human samples. Although restrictions are being introduced, they are still used in industrial processes as well as in consumer products. PFAAs cross the blood-brain-barrier and have been observed to induce adverse neurobehavioural effects in humans and animals as well as adverse effects in neuronal in ...
    • Plasmid-associated antimicrobial resistance and virulence genes in Escherichia coli in a high arctic reindeer subspecies 

      Sunde, Marianne; Ramstad, Silje N.; Rudi, Knut; Porcellato, Davide; Ravi, Anuradha; Ludvigsen, Jane; das Neves, Carlos Gonçalo; Tryland, Morten; Ropstad, Erik; Slettemeås, Jannice S.; Telke, Amar A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-30)
      Objectives - In extreme environments, such as the Arctic region, the anthropogenic influence is low and the presence of antimicrobial-resistant bacteria is unexpected. In this study, we screened wild reindeer (Rangifer tarandus platyrhynchus) from the Svalbard High Arctic Archipelago for antimicrobial-resistant Escherichia coli and performed in-depth strain characterisation.<p> <p>Methods - Using ...
    • 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 ...
    • Svalbard reindeer winter diets: Long-term dietary shifts to graminoids in response to a changing climate 

      Hiltunen, Tamara A.; Stien, Audun; Väisänen, Maria; Ropstad, Erik; Aspi, Jouni O.; Welker, Jeffery M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-07)
      Arctic ecosystems are changing dramatically with warmer and wetter conditions resulting in complex interactions between herbivores and their forage. We investigated how Svalbard reindeer (Rangifer tarandus platyrhynchus) modify their late winter diets in response to long-term trends and interannual variation in forage availability and accessibility. By reconstructing their diets and foraging ...