Morten Frederiksen

Morten Frederiksen
Aarhus University | AU · Department of Ecoscience

PhD, DSc

About

134
Publications
38,713
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Introduction
My research is focused along two lines of inquiry. Firstly, I am interested in the role of seabirds as top predators in marine ecosystems, and how they adapt to changing environments. Secondly, I use demographic analyses and modelling to investigate how changes in animal populations over time are determined by the environment they live in, including both abiotic, biotic and anthropogenic factors. My work is often linked to applied issues in conservation biology or wildlife management.
Additional affiliations
November 2002 - August 2007
April 2002 - November 2002
February 2001 - March 2002
Education
March 1995 - March 1998
University of Copenhagen
Field of study
  • Biology

Publications

Publications (134)
Article
Full-text available
We explored the implications of reaching the Paris Agreement Objective of limiting global warming to <2°C for the future winter distribution of the North Atlantic seabird community. We predicted and quantified current and future winter habitats of five North Atlantic Ocean seabird species (Alle alle, Fratercula arctica, Uria aalge, Uria lomvia and...
Article
Full-text available
The conservation of migratory marine species, including pelagic seabirds, is challenging because their movements span vast distances frequently beyond national jurisdictions. Here, we aim to identify important aggregations of seabirds in the North Atlantic to inform ongoing regional conservation efforts. Using tracking, phenology, and population da...
Article
Full-text available
Based on the Baltic Earth Assessment Reports of this thematic issue in Earth System Dynamics and recent peer-reviewed literature, current knowledge of the effects of global warming on past and future changes in climate of the Baltic Sea region is summarised and assessed. The study is an update of the Second Assessment of Climate Change (BACC II) pu...
Article
Full-text available
The rapidly changing climate in the Arctic is expected to have a major impact on the foraging ecology of seabirds, owing to changes in the distribution and abundance of their prey but also that of competitors (e.g. southerly species expanding their range into the Arctic). Species can respond to interspecific competition by segregating along differe...
Article
Full-text available
Understanding spatiotemporal variation in vital rates and population growth rates is a central aim of population ecology, and is critical to conservation of migratory species where different populations may spend the non-breeding season in sometimes widely separated areas. However, estimating those parameters and identifying the underlying drivers...
Article
Full-text available
We describe long-term changes in the distribution of 2249 freshly dead winter recoveries of 94,352 Great Cormorant chicks ringed between 1940 and 2018 in Denmark. The entire wintering range was divided into four major compartments to assess changes in (1) migratory distance and (2) the spatial distribution of recoveries. In the south-eastern winter...
Article
Density-dependent prey depletion around breeding colonies has long been considered an important factor controlling the population dynamics of colonial animals.1, 2, 3, 4 Ashmole proposed that as seabird colony size increases, intraspecific competition leads to declines in reproductive success, as breeding adults must spend more time and energy to f...
Article
Full-text available
Climate change alters species distributions by shifting their fundamental niche in space through time. Such effects may be exacerbated by increased inter-specific competition if climate alters species dominance where competitor ranges overlap. This study used census data, telemetry and stable isotopes to examine the population and foraging ecology...
Article
Southwest Greenland constitutes an internationally important wintering area for seabirds, including thick-billed murres (Uria lomvia Linnaeus, 1758), but their prey may be affected by the general warming of this sub-Arctic region. We compare murre diet collected in winter in the 1990s and 2010s around Nuuk. Fish made up 36% of the diet (wet mass) a...
Article
Full-text available
Segregation by sex can allow partitioning of resources in time, space, or both. Little, however, is known about causes of sexual segregation, especially in species with little to no sexual size dimorphism. Female and male thick-billed murres (a seabird, Uria lomvia) use habitat differently at subpolar latitude, and they temporally and spatially seg...
Article
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Each winter, the North Atlantic Ocean is the stage for numerous cyclones, the most severe ones leading to seabird mass-mortality events called ‘‘winter wrecks.’’ During these, thousands of emaciated seabird carcasses are washed ashore along European and North American coasts. Winter cyclones can therefore shape seabird population dynamics by affect...
Technical Report
Full-text available
This Climate Change Fact Sheet provides the latest scientific knowledge on how climate change is currently affecting the Baltic Sea and how it is expected to develop in the foreseeable future. It is aimed at guiding policymakers to take climate change into account, but also to the general public. Updated Baltic Sea Climate Change Fact Sheets are ex...
Preprint
Full-text available
Based on the Baltic Earth Assessment Reports of this thematic issue in Earth System Dynamics and recent peer-reviewed literature, current knowledge about the effects of global warming on past and future changes in climate of the Baltic Sea region is summarized and assessed. The study is an update of the Second Assessment of Climate Change (BACC II)...
Article
Differential migration strategies in the same population provide an opportunity to investigate the development and constraints of the migratory programme. We used data from birds ringed from the large Danish breeding population of Great Cormorants, Phalacrocorax carbo sinensis, to investigate age- and sex-specific differences in migratory patterns,...
Technical Report
Full-text available
The species status assessment for the Marine Strategy Framework Directive is structured around five Good Environmental Status (GES) criteria, i.e., by-catch rate, population abundance, population demographic characteristics, species distribution and habitat for the species. The MSFD Biodiversity theme for species includes, among others, some highly...
Article
An estimated 50% decline in Taiga Bean Geese A. fabalis between the mid-1990s and 2015 contrasted increasing numbers of Tundra Bean Goose A. serrirostris wintering in Western Europe at the same time. Seber dead-recovery analysis of metal-ringed individuals used to investigate year- and age effects on survival estimates from historical ringing data...
Article
Seabirds rarely cross major terrestrial barriers during seasonal migration, possibly because they have a limited ability to build up fat stores. For the first time, we tracked two Ivory Gulls with GPS loggers during spring migration from the wintering area in Davis Strait to the breeding colony in northeast Greenland. While one bird migrated in Mar...
Article
Full-text available
Spatio-temporal variation in population dynamics of migratory populations is shaped by exposure to different environments during the annual cycle. Hence, exposure to similar environments should translate into synchrony in vital rates. Despite a wide-ranging breeding population, the Baltic/Wadden Sea flyway population of eiders (Somateria m. molliss...
Article
Despite their unfavourable conservation status, little is known about the population status, trends and demography of Common Scoter Melanitta nigra. Capture-mark-recapture (CMR) data from 154 recapture events of 88 individually marked breeding female Common Scoter Melanitta nigra in the Aðaldalur valley, northeast Iceland, during 2009–2018 generate...
Chapter
Full-text available
EXECUTIVE SUMMARY • The seabird declines that commenced at the end of the last century have continued during the last two decades. • Further research into the causes of these declines is required if we are to fully understand the complex mechanisms operating, which are known to vary geographically. Climate change is considered to be one of the main...
Technical Report
Full-text available
This report describes the results from fieldwork carried out on breeding seabirds in Northeast Greenland as part of the Northeast Greenland Environmental Study Program. Results of GPS-tracking of Sabine’s gulls and ivory gulls are described, as well as surveys of thick-billed murre colonies and a variety of studies on little auks.
Article
Development of integrated population models (IPMs) assume the absence of systematic bias in monitoring programs, yet many potential sources of systematic bias in monitoring data exist (e.g., under-counts of abundance). By integrating multiple sources of data, we can assess whether various sources of monitoring data provide consistent inferences abo...
Article
Full-text available
The great auk was once abundant and distributed across the North Atlantic. It is now extinct, having been heavily exploited for its eggs, meat, and feathers. We investigated the impact of human hunting on its demise by integrating genetic data, GPS-based ocean current data, and analyses of population viability. We sequenced complete mitochondrial g...
Article
Full-text available
1. Harvested species population dynamics are shaped by the relative contribution of natural and harvest mortality. Natural mortality is usually not under management control, so managers must continuously adjust harvest rates to prevent overexploitation. Ideally, this requires regular assessment of the contribution of harvest to total mortality and...
Article
Full-text available
Brünnich's guillemot (Uria lomvia), or thick-billed murre, is an abundant pan-Arctic seabird, but several Atlantic breeding populations are declining. The species is subject to traditional harvest in the important wintering areas off west Greenland and Newfoundland, and has been subject to chronic oil pollution on the east coast of Canada. Until re...
Article
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Alternatives in ecosystem‐based management often differ with respect to trade‐offs between ecosystem values. Ecosystem or food‐web models and demographic models are typically employed to evaluate alternatives, but the approaches are rarely integrated to uncover conflicts between values. We applied multistate models to a capture–recapture dataset on...
Article
Full-text available
Like many seabirds, auks spend most of the year in offshore areas. Information on which oceanic areas they rely on throughout the winter is therefore important in understanding their population dynamics and establishing appropriate conservation measures. The breeding populations of Thick-billed Murres (Uria lomvia), Common Murres (Uria aalge) and R...
Article
Full-text available
Populations of migratory birds often mix to a considerable extent in their wintering areas. Knowledge about the composition of wintering populations is highly relevant to management, not least for species such as the great cormorant Phalacrocorax carbo sinensis, prone to conflicts with human interests. However, few studies have been able to estimat...
Article
Full-text available
The Spectacled Eider Somateria fischeri is a rare sea duck confined to breeding in the Yukon–Kuskokwim Delta and Arctic coasts of Alaska and Russia. Almost nothing is known about its status and breeding biology in the Russian Arctic. Stratified systematic nest searches were conducted annually of Spectacled Eider nests on Ayopechan Island in the Cha...
Article
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The Cormack-Jolly-Seber (CJS) model assumes that all marked animals have equal recapture probabilities at each sampling occasion, but heterogeneity in capture often occurs and should be taken into account to avoid biases in parameter estimates. Although diagnostic tests are generally used to detect trap-dependence or transience and assess the overa...
Article
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Carry-over effects, whereby events in one season have consequences in subsequent seasons, have important demographic implications. Although most studies examine carry-over effects across 2 seasons in single populations, the effects may persist beyond the following season and vary across a species’ range. To assess potential carry-over effects acros...
Article
The duration of parental care in animals varies widely, from none to lifelong. Such variation is typically thought to represent a trade-off between growth and safety. Seabirds show wide variation in the age at which offspring leave the nest, making them ideal to test the idea that a trade-off between high energy gain at sea and high safety at the n...
Article
Great Black-backed (Larus marinus), Lesser Black-backed (L. fuscus) and Herring (L. argentatus) gulls have all shown population increases and range expansion in Greenland in recent decades, but in very different ways. Great Black-backed Gulls increased from at least the 1960s from an established, local population. Lesser Black-backed Gulls immigrat...
Book
Full-text available
Climate change affects all components of marine ecosystems. For endothermic top predators, i.e. seabirds and marine mammals, these impacts are often complex and mediated through trophic relationships. In this Research Topic, leading researchers attempt to identify patterns of change among seabirds and marine mammals, and the mechanisms through whic...
Article
Ritenbenk/Innaq in Disko Bay is the only remaining Thick-billed Murre colony in central West Greenland. It has declined by 72% since 1980 and now (2012) holds c.1,100 breeding pairs. In 2005–2006 and 2011–2012, a number of studies were carried out in this colony to improve our understanding of the population decline and its causes. Hunting has prev...
Article
Sympatric nesting seabird species are often found to differ in one or more aspects of their foraging ecology. This is usually interpreted as resource partitioning, potentially due to current or past competition, but other explanations have been proposed. Three closely related species of alcids breeding together in subarctic southwest Greenland diff...
Article
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The ability to estimate mark loss of ringed animals is important to assess demographic parameters from mark-recapture studies correctly. Based on 23 years of neck collar recovery data from the Svalbard breeding population of Pink-footed Geese, we estimate an overall average annual loss rate of 3.2%. Neck collar loss was similar between males and fe...
Article
Full-text available
Lesser Snow Geese Chen caerulescens caerulescens (hereafter Snow Geese) use two wintering habitats in southwest Louisiana. Snow Geese in coastal marshes generally have larger bodies and proportionally thicker bills, longer skulls and longer culmen lengths than do those in adjacent rice-prairies. An important question is whether or not these morphs...
Thesis
Full-text available
Animal populations fluctuate in size over time, as a consequence of variation in their vital rates: per capita numbers of births and deaths. But what drives this variation? In broad terms, vital rates are affected by the environment animals find themselves in, including e.g. climate, availability of food, presence of predators, and impacts of human...
Technical Report
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As part of the environmental studies in connection with oil exploration in Baffin Bay, baseline studies of seabird ecology were carried out at colonies north of Upernavik during the summers of 2008-13. The main study species were thick-billed murre and black-legged kittiwake. GPS tracking of both species showed that important foraging areas during...
Article
Full-text available
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...
Article
Large population declines were reported for the thick-billed murre (Uria lomvia) in Greenland for the period 1930s–1980s, but no national status has been published for the past 20 years. Meanwhile, the murres have gained more protection and several human-induced mortality factors have been markedly reduced. Here, we give an updated status based on...
Article
Full-text available
Conservation and management of migratory waterbirds use flyway populations as the basic unit, and knowledge of the delineation, rate of exchange and gene flow between populations is fundamental. However, for the majority of global flyway populations, information is too fragmentary to address connectivity between populations and, hence, insufficient...
Article
Full-text available
In a rapidly changing world, understanding and predicting population change is a central aim of applied ecologists, and this involves studying the links between environmental variation and vital rates (survival, fecundity, etc.). Demographic analysis and modelling can be daunting for practicing ecologists, and here we provide an overview of some of...
Article
Full-text available
Leg-mounted loggers are increasingly used in seabird activity studies, but few studies have validated the information obtained about bird behaviour with independent data. Using Brünnich’s Guillemot Uria lomvia as a study species, we show by comparing interpretations of time–depth recorder (TDR) data with visual observations that activity budgets in...
Article
Full-text available
When species competing for the same resources coexist, some segregation in the way they utilize those resources is expected. However, little is known about how closely related sympatric breeding species segregate outside the breeding season. We investigated the annual segregation of three closely related seabirds (razorbill Alcatorda, common guille...
Data
Spatial distribution of auks on an annual cycle. Distribution of razorbills (n = 8, blue), common guillemots (n = 8, red) and Brünnich’s guillemots (n = 6, black) during the non-breeding season in 2009/2010 and 2010/2011 based on GLS data. The panels show the monthly median position of each bird in August through to April. (TIF)
Article
Full-text available
Capsule: The presence of avian cholera depressed annual survival of female Common Eiders in a Danish colony. Aims: To estimate the annual survival of adult female Common Eiders in the colony of Helleholm, Denmark, and evaluate the effect of winter temperature and avian cholera on survival. Methods: Breeding females were captured and ringed during o...
Article
The boreal Northeast Atlantic is strongly affected by current climate change, and large shifts in abundance and distribution of many organisms have been observed, including the dominant copepod Calanus finmarchicus, which supports the grazing food web and thus many fish populations. At the same time, large-scale declines have been observed in many...
Technical Report
Full-text available
This report is a strategic environmental impact assessment of activities related to exploration, development and exploitation of oil in the Greenland sector of the Labrador Sea and the southeast Davis Strait.