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Recent decline in body condition of departing Common Guillemots Uria aalge at Hornøya, North Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2010)
Since 1980, there has been large variation and a recent decline in the mass and body condition of Common Guillemot Uria aalge chicks departing from the nest site in NE Norway. This may be related to deterioration in the feeding conditions off the colony and is alarming considering the critically endangered status of the species in Norway. To measure body condition, earlier studies have caught, weighed ...
Virological and serological surveillance for type A influenza in the black-legged kittiwake (Rissa tridactyla)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
The epidemiology of avian influenza viruses (AIVs) in gulls is only partially known. The role of the world's most numerous gull species, the black-legged kittiwake (Rissa tridactyla), as a potential AIV reservoir species has been unclear. The prevalence of AIV and humoral response against AIV were therefore studied in a colony of apparently healthy black-legged kittiwakes breeding in a nesting cliff ...
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
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-04-29)
Predicting the impact of global climate change 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 of the consequences of these changes on populations is limited. The North Atlantic Oscillation (NAO) has been used as a proxy for “climate” in several ecological studies, but this ...
Long-term decline in egg size of Atlantic puffins Fratercula arctica is related to changes in forage fish stocks and climate conditions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
Due to major shifts in the marine ecosystem, many seabirds in the NE Atlantic have experienced short- and long-term breeding failures and population changes. One such seabird is the Atlantic puffin Fratercula arctica, the populations of which have declined in Norway at an annual rate of 2% over a ~30 yr period. Parallel to this decline, we found a significant decline in egg volume at 2 widely ...
Ocean climate and egg investment in the black-legged kittiwake Rissa tridactyla.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-14)
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 thus vary in response to food availability prior to egg laying. We investigated the variation in egg and clutch size of black-legged kittiwakes Rissa tridactyla in a North Norwegian ...
When things go wrong: intra-season dynamics of breeding failure in a seabird
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-01-16)
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 individual behavior, carry-over effects, dispersal decisions and population
dynamics, little information is currently available on these dynamics at fine temporal scales. Here, ...
On the polar edge: the status of the northern gannet (Morus bassanus) in the Barents Sea in 2015-2016.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-27)
During its population recovery in the North Atlantic in the early 1900s, the northern gannet (Morus bassanus) established its first colony in Norway at Runde in 1946. Since the 1960s,
gannets have established (and later abandoned) several small colonies in the north of the country. These colonies have been regularly monitored, and in 2015–16 ca. 3300 apparently
occupied nests (AON) were counted ...
Prey density in non-breeding areas affects adult survival of black-legged kittiwakes Rissa tridactyla
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-08-27)
In migratory birds, environmental conditions in both breeding and non-breeding areas may affect adult survival rates and hence be significant drivers of demographic processes. In seabirds, poor knowledge of their true distribution outside the breeding season, however, has severely limited such studies. This study explored how annual adult survival rates of black-legged kittiwakes Rissa tridactyla ...
Upwind or downwind: the spring arrival of Arctic Terns Sterna paradisaea at Troms, north Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-13)
Arctic Terns Sterna paradisaea have a record-long migration between their breeding grounds in the Arctic and wintering areas in the Antarctic. Nevertheless, return dtaes to north Norway were remarkably constant over a 35-y period (1981-2015), arriving in Troms within a 13-d time window in mid to late May. Since 1993, arrival dates have advanced by about four days. No relationships were found between ...
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 ...