• Antiparasite treatments reduce humoral immunity and impact oxidative status in raptor nestlings 

      Hanssen, Sveinn Are; Bustnes, Jan Ove; Schnug, Lisbeth; Bourgeon, Sophie; Johnsen, Trond Vidar; Ballesteros, Manuel; Sonne, Christian; Herzke, Dorte; Eulaers, Igor; Jaspers, Veerle; Covaci, Adrian; Eens, Marcel; Halley, Duncan John; Moum, Truls Borg; Ims, Rolf Anker; Erikstad, Kjell E (Journal article; Peer reviewed, 2013)
      Parasites are natural stressors that may have multiple negative effects on their host as they usurp energy and nutrients and may lead to costly immune responses that may cause oxidative stress. At early stages, animals ...
    • Circumpolar dynamics of a marine top-predator track ocean warming rates 

      Descamps, Sebastian; Anker-Nilssen, Tycho; Barrett, Robert T; Irons, D; Merkel, Flemming; Robertson, Gregory J.; Yoccoz, Nigel Gilles; Mallory, Mark L; Montevecchi, William A.; Boertmann, D.; Artukhin, Yuri; Christensen-Dalsgaard, Signe; Erikstad, Kjell E; Gilchrist, H. Grant; Labansen, Aili; Lorentsen, Svein Håkon; Mosbech, Anders; Olsen, Bergur; Petersen, Aevar; Rail, Jean-Francois; Renner, Heather M.; Strøm, H.; Systad, Geir Helge; Wilhelm, Sabina I.; Zelenskaya, Larisa (Journal article; Peer reviewed, 2017)
      Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of ...
    • Climate fluctuations and differential survival of bridled and non-bridled Common Guillemots Uria aalge 

      Reiertsen, Tone Kristin; Erikstad, Kjell E; Barrett, Robert T; Sandvik, Hanno; Yoccoz, Nigel (Journal article; Peer reviewed, 2012)
      Climate fluctuations and its effects on ecological processes are evident in most areas worldwide but whether such climatic effects are induced phenotypic plasticity or whether animals adapt to the new environment through ...
    • Forage fish abundance is a predictor of timing of breeding and hatching brood size in a coastal seabird 

      Lorentsen, Svein-Håkon; Anker-Nilssen, Tycho; Erikstad, Kjell E; Røv, Nils (Journal article; Peer reviewed, 2015)
      Current and future climate alterations might impact ecological processes like timing of breeding. We used multivariate linear models to assess the importance of food availability and climate on timing of breeding and ...
    • Later at higher latitudes: large-scale variability in seabird breeding timing and synchronicity 

      Burr, Zofia M.; Varpe, Øystein; Anker-Nilssen, Tycho; Erikstad, Kjell E; Descamps, Sébastien; Barrett, Robert T; Bech, Claus; Christensen-Dalsgaard, Signe; Lorentsen, Svein-Håkon; Moe, Børge; Reiertsen, Tone Kristin; Strøm, Hallvard (Journal article; Peer reviewed, 2016-05-28)
      In seasonal environments, organisms are expected to optimally schedule reproduction within an annual range of environmental conditions. Latitudinal gradients generate a range of seasonality to which we can expect adaptations ...
    • Modelled drift patterns of fish larvae link coastal morphology to seabird colony distribution 

      Sandvik, Hanno; Barrett, Robert T; Erikstad, Kjell E; Myksvoll, Mari Skuggedal; Vikebø, Frode Bendiksen; Yoccoz, Nigel Gilles; Anker-Nilssen, Tycho; Lorentsen, Svein-Håkon; Reiertsen, Tone; Skardhamar, Jofrid; Skern-Mauritzen, Mette; Systad, Geir Helge (Journal article; Peer reviewed, 2016-05-13)
      Colonial breeding is an evolutionary puzzle, as the benefits of breeding in high densities are still not fully explained. Although the dynamics of existing colonies are increasingly understood, few studies have addressed ...
    • Moult location and diet of auks in the North Sea inferred from coupled light-based and isotope-based geolocation 

      Glew, Katie St. John; Wanless, Sarah; Harris, Michael P.; Daunt, Francis; Erikstad, Kjell E; Strøm, Hallvard; Trueman, Clive N. (Journal article; Peer reviewed, 2018)
      Many pelagic seabirds moult their feathers while at sea, which is an energetically costly behaviour. Mortality rates during moult can be high, so spatial and trophic ecology during this critical period is important for ...
    • Ocean climate and egg investment in the black-legged kittiwake Rissa tridactyla. 

      Barrett, Robert T; Erikstad, Kjell E; Reiertsen, Tone (Journal article; Peer reviewed, 2017)
      Birds allocate substantial resources to their eggs during the laying period, resources also needed for other concurrent costly processes such as mate acquisition, nest building and site defence. Egg and clutch sizes may ...
    • Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment 

      Lorentsen, Svein Håkon; Anker-Nilssen, Tycho; Erikstad, Kjell E (Journal article; Peer reviewed, 2018)
      In fisheries management, assessing year-class strength and recruitment to commercial stocks is essential, but can be difficult to do for fish species where the young stages are inaccessible to ship-based surveys. This is ...
    • Sympatric Atlantic puffins and razorbills show contrasting responses to adverse marine conditions during winter foraging within the North Sea 

      St. John Glew, Katie; Wanless, Sarah; Harris, Michael P.; Daunt, Francis; Erikstad, Kjell E; Strøm, Hallvard; Speakman, John R.; Kürten, Benjamin; Trueman, Clive N. (Journal article; Peer reviewed, 2019)
      Background: Natural environments are dynamic systems with conditions varying across years. Higher trophic level consumers may respond to changes in the distribution and quality of available prey by moving to locate new ...
    • The stress hormone corticosterone in a marine top predatorreflects short-term changes in food availability 

      Barrett, Robert; Erikstad, Kjell E; Sandvik, Hanno; Myksvoll, Mari Skuggedal; Jenni-Eiermann, Susi; Kristensen, Ditte Lyngbo; Moum, Truls; Reiertsen, Tone; Vikebø, Frode Bendiksen (Journal article; Peer reviewed, 2015)
      In many seabird studies, single annual proxies of prey abundance have been used to explain variability in breeding performance, but much more important is probably the timing of prey availability relative to the breeding ...
    • There is more to climate than the North Atlantic Oscillation: a new perspective from climate dynamics to explain the variability in population growth rates of a long-lived seabird 

      Mesquita, Michel d. S.; Erikstad, Kjell E; Sandvik, Hanno; Reiertsen, Tone; Barrett, Robert; Anker-Nilssen, Tycho; Hodges, Kevin I.; Bader, Jürgen (Journal article; Peer reviewed, 2015)
      Predicting the impact of global climat echange on the biosphere has become one of the most important efforts in ecology. Ecosystems worldwide are changing rapidly as a consequence of global warming, yet our understanding ...
    • When things go wrong: intra-season dynamics of breeding failure in a seabird 

      Ponchon, Aurore; Grémillet, David J.H.; Christensen-Dalsgaard, Signe; Erikstad, Kjell E; Barrett, Robert T.; Reiertsen, Tone Kristin; McCoy, Karen D.; Tveraa, Torkild; Boulinier, Thierry (Journal article; Peer reviewed, 2014)
      During breeding, long-lived species face important time and energy constraints that can lead to breeding failure when food becomes scarce. Despite the potential implications of intra-season dynamics in breeding failure for ...