Blar i forfatter "Frafjord, Karl"
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Activity patterns of the soprano pipistrelle Pipistrellus pygmaeus throughout the year in southern Norway
Frafjord, Karl (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-09)<i>Background</i> - Most temperate bats are regular hibernators in the winter. Knowledge about the length of their active season and how they adjust their nightly activity throughout the season, is critical to conservation. The characteristics of these are likely to vary with climate as well as latitude. This study investigated the flight activity of the soprano pipistrelle <i>Pipistrellus pygmaeus</i> ... -
The distribution limit of the common tick, Ixodes ricinus, and some associated pathogens in north-western Europe
Hvidsten, Dag; Frafjord, Karl; Gray, Jeremy S.; Henningsson, Anna Jonsson; Jenkins, Andrew; Kristiansen, Bjørn Erik; Lager, Malin; Rognerud, Bjørg; Slåtsve, Arne Martin; Stordal, Frode; Stuen, Snorre; Wilhelmsson, Peter (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-03)In north-western Europe, the common tick, <i>Ixodes ricinus</i>, is widely established, its distribution appears to be increasing and the spread of tick-borne diseases is of increasing concern. The project <i>‘Flått i Nord’</i> (Ticks in northern Norway) commenced in spring 2009 with the intention of studying the tick’s distribution and that of its pathogens in northern Norway. Several methods were ... -
Grazing by sheep Ovis aries reduces island populations of water voles Arvicola amphibius
Frafjord, Karl (Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Influence of night length on home range size in the northern bat Eptesicus nilssonii
Frafjord, Karl (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-04)The northern bat Eptesicus nilssonii is widespread in Fennoscandia, with breeding populations well above the Arctic Circle. I studied this species at its extreme northern limit, at 69°N in Norway. I radio-tracked 17 bats from 2 maternity roosts during 2003–2006 to study the influence of the midnight sun and increasing lengths of darkness on activity (time spent out of roost) and home range size. ... -
The influence of night length: Activity of the northern bat Eptesicus nilssonii under conditions of continuous light in midnight sun compared to a southern population
Frafjord, Karl (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-13)Background - Nearly all insectivorous bats (Chiroptera) are strictly nocturnal, flying and feeding only between sunset and sunrise despite lower insect availability than by day, most likely to avoid predation by diurnal birds. This may represent a great challenge to bats living north of the Arctic Circle, which are exposed to bright nights in the period of the midnight sun. The northern bat Eptesicus ... -
Influence of Reproductive Status: Home Range Size in Water Voles (Arvicola amphibius)
Frafjord, Karl (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-26)The relationship between home range and reproductive status of water voles (Arvicola amphibius) was studied by radio-tracking on an island off the coast of northern Norway in 2006–2009. The aim was to test assumptions about the species’ social structure relative to other microtines. Juveniles used fairly small ranges (about 400 m²), with no difference between males and females. Subadults, overwintered ... -
Population dynamics of an island population of water voles Arvicola amphibius (Linnaeus, 1758) with one major predator, the eagle owl Bubo bubo (Linnaeus, 1758), in northern Norway
Frafjord, Karl (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-09)Predator–prey relationships are of great significance to ecosystems, and their effects on the population dynamics of voles and lemmings (Microtinae) in Boreal and Arctic environments have long been of particular interest. A simple ecosystem with one major prey and one major predator could be an ideal setting for a study of their interactions. This is the situation on several small islands on the ...