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norskBlar i forfatter Norges arktiske universitetsmuseum "Lorentsen, Svein-Håkon"
Viser treff 1-14 av 14
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The decline of Norwegian kittiwake populations: modelling the role of ocean warming.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014)The black-legged kittiwake Rissa tridactyla is a pelagic seabird whose population has recently declined in most parts of the North Atlantic and which is red-listed in most bordering countries. To investigate a possible cause for this decline, we analysed the population dynamics of 5 kittiwake colonies along the Norwegian coast, ranging from 62° to 71° N, over the last 20 to 35 yr. By quantifying the ... -
Global phenological insensitivity to shifting ocean temperatures among seabirds
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-02)Reproductive timing in many taxa plays a key role in determining breeding productivity, and is often sensitive to climatic conditions. Current climate change may alter the timing of breeding at different rates across trophic levels, potentially resulting in temporal mismatch between the resource requirements of predators and their prey. This is of particular concern for higher-trophic-level organisms, ... -
Later at higher latitudes: large-scale variability in seabird breeding timing and synchronicity
(Journal article; Tidsskriftartikkel; 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 to have evolved, and can be used to explore drivers of timing strategies across species’ distribution ranges. This study compares the timing of egg hatching in four seabird ... -
Levedyktighetsanalyser for norske lomvibestander
(Research report; Forskningsrapport, 2007-03)Hekkebestandene av lomvi (Uria aalge) langs norskekysten har hatt en sterk nedgang i løpet av de siste 45 årene. Den norske fastlandsbestanden utgjør i dag ikke mer enn ca 15 000 par, mens den til sammenligning ble beregnet til 120-160 000 par i begynnelsen av 1960-årene. Den største bestanden i norske områder finnes i dag på Bjørnøya hvor det hekker ca 100 000 par, men også her er bestanden ... -
Metapopulation regulation acts at multiple spatial scales: Insights from a century of seabird colony census data
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-27)Density-dependent feedback is recognized as important regulatory mechanisms of population size. Considering the spatial scales over which such feedback operates has advanced our theoretical understanding of metapopulation dynamics. Yet, metapopulation models are rarely fit to time-series data and tend to omit details of the natural history and behavior of long-lived, highly mobile species such as ... -
Modelled drift patterns of fish larvae link coastal morphology to seabird colony distribution
(Journal article; Tidsskriftartikkel; 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 the initial formation of colonies, and empirical tests are rare. Using a high-resolution larval drift model, we here document that the distribution of seabird colonies along the ... -
Multicolony tracking reveals the winter distribution of a pelagic seabird on an ocean basin scale
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011-11-26)Aim An understanding of the non-breeding distribution and ecology of migratory species is necessary for successful conservation. Many seabirds spend the nonbreeding season far from land, and information on their distribution during this time is very limited. The black-legged kittiwake, Rissa tridactyla, is a widespread and numerous seabird in the North Atlantic and Pacific, but breeding ... -
Population status, breeding biology and diet of Norwegian Great Cormorants
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-01)Two subspecies of the Great Cormorant breed in Norway, the continental Phalacrocorax carbo sinensis in the south, along the Skagerrak coast, and the marine P. c. carbo from central Norway and northwards. Here we review the information existing until 2017 on population status and trends, breeding performance and diet of these two subspecies in Norway. The most recent national population estimates are ... -
Prevailing weather conditions and diet composition affect chick growth and survival in the black-legged kittiwake
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-04)To identify priorities for management of seabirds during the breeding season, it is important to understand the ecological mechanisms driving chick growth and survival. In this study, we examined the effects of diet and prevailing weather on the growth and survival of chicks of black-legged kittiwakes Rissa tridactyla over a 10 yr period at Anda, a seabird colony in northern Norway. We show that ... -
SEAPOP studies in the Barents and Norwegian Seas in 2007
(Research report; Forskningsrapport, 2008-04)This is the third annual report of the SEAPOP programme, which was initiated in 2005. In 2007, the work continued at full scale in the Lofoten-Barents Sea area, and similar studies were initiated in the southern part of the Norwegian Sea. The report is divided into three sections. The first is an executive summary, the second presents five selected highlights from the studies in 2007, whereas the ... -
SEAPOP studies in the Lofoten and Barents Sea area in 2006
(Research report; Forskningsrapport, 2007-04)This is the second annual report of the SEAPOP programme, which was initiated in 2005. In 2006, the programme was extended to the near full scale in the Lofoten-Barents Sea area, but it is aimed for implementation at the national level within few years. The report is divided into three sections. The first is an executive summary, the second presents five selected highlights from the studies in ... -
SEAPOP. Et nasjonalt sjøfuglprogram for styrket beslutningsstøtte i marine områder
(Research report; Forskningsrapport, 2005-01)SEAPOP (Seabird population management and petroleum operations) er et nasjonalt, kunnskapsoppbyggende program om sjøfugl tilrettelagt for å gi styrket beslutningsstøtte for marine områder. Konseptet ble først utviklet for oljeindustrien i et samarbeid mellom Norsk institutt for naturforskning (NINA) og Den norske stats oljeselskap as (Statoil), men er senere videreutviklet i samarbeid med Norsk ... -
The status and trends of seabirds breeding in Norway and Svalbard
(Research report; Forskningsrapport, 2015-03)This report presents the updated sizes, trends and spatial distributions of the breeding populations of 17 seabird species breeding in Norway and Svalbard. The analyses are based on available census and monitoring data from SEAPOP; the Norwegian monitoring and mapping program for seabirds. In addition, the report presents results from a species-specific literature review of the most important ... -
Twilight foraging enables European shags to survive the winter across their latitudinal range
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-14)Species breeding at high latitudes face a significant challenge of surviving the winter. Such conditions are particularly severe for diurnal marine endotherms such as seabirds. A critical question is therefore what behavioural strategies such species adopt to maximise survival probability. We tested 3 hypotheses: (1) they migrate to lower latitudes to exploit longer day length (‘sun-chasing’), (2) ...
