Blar i forfatter "Stokkan, Karl-Arne"
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Cryptic impact: Visual detection of corona light and avoidance of power lines by reindeer
Tyler, N. J. C.; Stokkan, Karl-Arne; Hogg, Christopher; Nellemann, C; Vistnes, Arnt Inge (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-06)Assessing the impact of human development on animals is complicated by the fact that overt effects may have covert causes. Cryptic impacts (sensu Raiter et al. 2014) can arise where sensory stimuli to which species respond fall outside the human sensory range. Ultraviolet (UV) light, which is detected by a range of nonprimate mammals, is a potential example. We review evidence that dark-adapted eyes ... -
The eyes of the deep diving hooded seal (Cystophora cristata) enhance sensitivity to ultraviolet light
Hogg, Chris; Neveu, Magella; Folkow, Lars; Stokkan, Karl-Arne; Kam, Jaimie Hoh; Douglas, Ron H; Jeffery, Glen (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-11)The mammalian visual range is approximately 400–700 nm, although recent evidence suggests varying ultraviolet (UV) extensions in diverse terrestrial species. UV sensitivity may have advantages in the dim, blue light shifted environment experienced by submerged marine mammals. It may also be advantageous when seals are on land as UV is reflected by snow and ice but absorbed by fur, enhancing visual ... -
Neither season nor sex affects the cost of terrestrial locomotion in a circumpolar diving duck: The common eider (Somateria mollissima)
Rose, Kayleigh A.; Tickle, Peter G.; Lees, John J; Stokkan, Karl-Arne; Codd, Jonathan R (Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Reduced Metabolic Cost of Locomotion in Svalbard Rock Ptarmigan (Lagopus muta hyperborea) during Winter
Lees, J; Nudds, R; Stokkan, Karl-Arne; Folkow, Lars; Codd, J (Journal article; Tidsskriftartikkel; Peer reviewed, 2010) -
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer
Stokkan, Karl-Arne; Folkow, Lars; Dukes, Juliet; Neveu, Magella; Hogg, Chris R; Siefken, Sandra Katharina Christiane; Dakin, Steven C; Jeffery, Glen (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-12-22)Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep ... -
Ultraviolet vision and avoidance of power lines in birds and mammals
Tyler, N. J. C.; Stokkan, Karl-Arne; Hogg, Chris; Nellemann, Christian; Vistnes, Arnt Inge; Jeffery, Glen (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)No abstract