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result(s) for
"Boertmann, David"
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Decline in the West Greenland population of a zooplanktivorous seabird, the little auk Alle alle
by
Wojczulanis-Jakubas, Katarzyna
,
Petersen, Aevar
,
Evans, Peter G. H.
in
631/158/2165
,
631/158/852
,
Alle alle
2024
The warming of the Arctic had lead to a diverse range of impacts on local biota, including northward shifts of some species range. Here, we report past and present distribution and abundance of an Arctic zooplanktivorous seabird, the little auk
Alle alle
in West Greenland south of 74° N, and examine the changes in sea surface temperature (SST) and sea ice concentration (SIC) in the birds foraging areas in 1850–2007. We estimated the little auk population in the studied region to be 5,200 pairs in the 1930s, 6,000–6,500 pairs in the 1940-1970s and 70–80 pairs by the 2000s. We found that periods with increased SST and reduced SIC, especially in the last few decades, coincided with little auk population declines. Besides, years with little auk presence in breeding sites were characterized by either low SST and low to moderate SIC or higher SST but moderate to high SIC. Observed contraction of the breeding range and a decrease in abundance of the little auk may be attributed to more complex climate-driven changes in the marine ecosystem at finer spatial and temporal scales and/or cannot be easily detected given the coarseness of data used. It is possible that the population in this region has never been very numerous being subjected to local impacts such as disease, bycatch, predation, etc. The climate warming that is currently being observed, along with corresponding shifts in zooplankton communities, may lead to extirpation of the studied little auk populations.
Journal Article
Observations of bowhead whales in west Greenland during summer
by
Johansen, Kasper L.
,
Raundrup, Katrine
,
Nymand, Josephine
in
Aquatic mammals
,
balaena mysticetus
,
Balaenidae
2023
Bowhead whales (Baleana mysticetus) are usually away from west Greenland waters during summer. Reported here is an observation of at least six bowhead whales in July 2022 in the Uummannaq Fjord system of west Greenland.
Journal Article
Animal behavioral adaptation to changing landscapes: spring-staging geese habituate to wind farms
by
Madsen, Jesper
,
Boertmann, David
in
Adaptation
,
Animal behavior
,
Animal, plant and microbial ecology
2008
Wind farms are positioned in open landscapes and may cause loss of wildlife habitat due to disturbance, fragmentation, and infrastructure development. Especially flocking geese, swans, ducks and waders are regarded as vulnerable to wind farm development. We compared past and current displacement effects of two onshore wind farms and a line of land-based turbines on spring-staging pink-footed geese (Anser brachyrhynchus) to see if there was evidence of habituation. In one wind farm area, geese previously (1998) (Larsen and Madsen 2000) kept a distance of c. 200 m (the distance at which 50% of peak densities is reached) and they did not go between the turbines; today (2008) they keep a distance of c. 100 m, but do still not enter the wind farm area. In another wind farm, where foraging geese previously (2000) kept a distance of more than 100 m and did not enter the wind farm, they now (2008) forage between the wind turbines and keep a distance of c. 40 m to turbines. In 1998, geese kept a distance of 125 m to a line of turbines, compared to 50 m now. We conclude that geese have behaviorally adapted to changing landscapes created by wind farms. The difference in avoidance between the sites may be due to the sizes of the turbines which in this study were small in both rotor-swept area and in height compared to more recent “industry standard” of 2.5 and 3.0 MW turbines. The study points to the need for longer term studies to properly assess the impact of wind farms on wildlife, including consequent increased risks from inclement weather events of feeding, rafting, and migrating waterfowl.
Journal Article
Latitudinal gradients in sea ice and primary production determine Arctic seabird colony size in Greenland
2008
Sea ice loss will indirectly alter energy transfer through the pelagic food web and ultimately impact apex predators. We quantified spring-time trends in sea ice recession around each of 46 thick-billed murre (Uria lomvia) colonies in west Greenland across 20° of latitude and investigated the magnitude and timing of the associated spring-time primary production. A geographical information system was used to extract satellite-based observations of sea ice concentration from the Nimbus-7 scanning multichannel microwave radiometer (SMMR, 1979-1987) and the Defence Meteorological Satellite Programs Special Sensor Microwave/Imager (SSMI, 1987-2004), and satellite-based observations of chlorophyll a from the moderate resolution imaging spectroradiometer (MODIS: EOS-Terra satellite) in weekly intervals in circular buffers around each colony site (150 km in radius). Rapid recession of high Arctic seasonal ice cover created a temporally predictable primary production bloom and associated trophic cascade in water gradually exposed to solar radiation. This pattern was largely absent from lower latitudes where little to no sea ice resulted in a temporally variable primary production bloom driven by nutrient cycling and upwelling uncoupled to ice. The relationship between the rate and variability of sea ice recession and colony size of thick-billed murres shows that periodical confinement of the trophic cascade at high latitudes determines the carrying capacity for Arctic seabirds during the breeding period.
Journal Article
Seabird Breeding Colonies in East and North Greenland
2020
This paper presents the results of a number of aircraft- and boat-based surveys for seabird breeding colonies in East and North Greenland carried out in the period 2003 to 2018 and gives the first comprehensive overview of the distribution and size of the seabird breeding colonies in this remote and mainly uninhabited region. Seventeen seabird species breed in approximately 800 sites distributed very unevenly along the coasts, with high concentrations at the polynyas and long stretches with very few breeding seabirds. Climate changes are in full progress in East and North Greenland, especially affecting the sea ice regime, and seabirds are expected to respond to these changes in different ways. For example, since the 1980s, Common Eiders (Somateria mollissima) have extended their breeding range more than two latitudinal degrees towards the north, now reaching the northernmost land on Earth. Lesser Black-backed Gulls (Larus fuscus) and Great Cormorants (Phalacrocorax carbo) have immigrated, and Sabine’s Gulls (Xema sabini) have increased and extended their range. Besides presenting survey results, this report may also serve as a baseline for future studies of the abundance of breeding seabirds in East and North Greenland.
Cet article présente les résultats de comptages de colonies d’oiseaux marins nicheurs menés en bateau et en avion dans l’est et le nord du Groenland entre 2003 et 2018. Il s’agit de la première synthèse globale consacrée à la distribution et à la taille des colonies de reproduction d’oiseaux marins pour cette région reculée et principalement inhabitée. Dix-sept espèces d’oiseaux marins se reproduisent sur environ 800 sites répartis de façon très irrégulière le long des côtes, avec de fortes concentrations aux alentours des polynies, mais aussi de grandes régions avec très peu d’oiseaux marins nicheurs. Les changements climatiques sont déjà très perceptibles dans l’est et le nord du Groenland. Ils y impactent fortement le régime de la banquise et on s’attend à ce que les oiseaux marins y répondent de différentes façons. L’eider à duvet (Somateria mollissima) a par exemple étendu son aire de distribution de plus de deux degrés de latitude vers le nord depuis les années 1980, atteignant les terres les plus septentrionales au monde. Le goéland brun (Larus fuscus) et le grand cormoran (Phalacrocorax carbo) se sont installés alors que la mouette de Sabine (Xema sabini) a étendu son aire de distribution et a vu ses effectifs augmenter. En plus de présenter des résultats de comptages, cette étude pourra également servir d’état initial pour évaluer à l’avenir les changements d’abondance et de distribution des oiseaux marins nicheurs dans l’est et le nord du Groenland.
Journal Article
Status of Greenland Populations of Great Black-Backed Gull (Larus marinus), Lesser Black-Backed Gull (Larus fuscus) and Herring Gull (Larus argentatus)
2016
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 immigrated from Iceland in the 1980s, spread rapidly over most of the southern part of Greenland and are common and abundant today. Herring Gulls also immigrated in the 1980s, but only established a small, scattered, and, at many sites, irregular breeding population. Here, we present the most recent information on the status and trends of Great Black-backed Gull, Lesser Black-backed Gull and Herring Gull populations in Greenland.
Journal Article
Ivory gulls breeding on ice
by
Boertmann, David
,
Gilg, Oliver
,
Olsen, Kent
in
Animal populations
,
Animal reproduction
,
Biodiversity
2010
A breeding colony of ivory gulls was discovered on an ice floe in northeast Greenland in August 2008. The ice floe resembled nearby islands in that it was covered with a thick layer of gravely moraine, and furthermore its position was fixed throughout most of the breeding season as the surrounding first year ice only broke up in mid August when most of the gull chicks had fledged.
Journal Article
Molecular phylogeny, morphology, pigment chemistry and ecology in Hygrophoraceae (Agaricales)
2014
Molecular phylogenies using 1–4 gene regions and information on ecology, morphology and pigment chemistry were used in a partial revision of the agaric family Hygro- phoraceae. The phylogenetically supported genera we recognize here in the Hygrophoraceae based on these and previous analyses are:
Acantholichen
,
Ampulloclitocybe
,
Arrhenia
,
Cantharellula, Cantharocybe, Chromosera
,
Chrysomphalina, Cora
,
Corella
,
Cuphophyllus, Cyphellostereum
,
Dictyonema, Eonema
,
Gliophorus, Haasiella
,
Humidicutis, Hygroaster, Hygrocybe
,
Hygrophorus
,
Lichenomphalia, Neohygrocybe, Porpolomopsis
and
Pseudoarmillariella
. A new genus that is sister to
Chromosera
is described as
Gloioxanthomyces
. Revisions were made at the ranks of subfamily, tribe, genus, subgenus, section and subsection. We present three new subfamilies, eight tribes (five new), eight subgenera (one new, one new combination and one stat. nov.), 26 sections (five new and three new combinations and two stat. nov.) and 14 subsections (two new, two stat. nov.). Species of
Chromosera
,
Gliophorus, Humidicutis,
and
Neohygrocybe
are often treated within the genus
Hygrocybe;
we therefore provide valid names in both classification systems. We used a minimalist approach in transferring genera and creating new names and combinations. Consequently, we retain in the Hygrophoraceae the basal cuphophylloid grade comprising the genera
Cuphophyllus, Ampulloclitocybe
and
Cantharocybe,
despite weak phylogenetic support. We include
Aeruginospora
and
Semiomphalina
in Hygrophoraceae based on morphology though molecular data are lacking. The lower hygrophoroid clade is basal to Hygrophoraceae s.s., comprising the genera
Aphroditeola, Macrotyphula, Phyllotopsis, Pleurocybella, Sarcomyxa, Tricholomopsis
and
Typhula
.
Journal Article
Declining trends in the majority of Greenland’s thick-billed murre (Uria lomvia) colonies 1981–2011
by
Linnebjerg, Jannie Fries
,
Mosbech, Anders
,
Merkel, Flemming
in
Animal and plant ecology
,
Animal populations
,
Animal, plant and microbial ecology
2014
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 the past 30 years of murre count data. The total Greenland population in 2011 was estimated to 468,300 birds (95 % CI 430,700–505,900) or around 342,000 breeding pairs, distributed within 19 colonies. This represents an overall reduction of 13 % since the mid-/late 1980s. In the same period, five colonies went extinct. Large and apparently stable colonies in Qaanaaq (Northwest Greenland) account for more than half the population (68 %), but most other colonies declined heavily, with up to 6 % p.a. in the most critical areas. So far, nothing indicates that food is a limiting factor in Greenland during the breeding season, although rather few colonies have been studied in details. In contrast, illegal hunting and disturbances during the breeding season are still a problem in Greenland, despite more restrictive hunting regulations, and may explain much of the continued population decline. In addition, recent studies from Svalbard indicate that a large-scale deterioration of the marine environment in the North Atlantic, due to oceanographic changes, may impact recruitment to some of the Greenland colonies. Murre colonies in southern Upernavik, Disko Bay, South Greenland and East Greenland are in urgent need of additional conservation initiatives to avoid further declines and local extinctions.
Journal Article