63 research outputs found
Distribution and Conservation of the Harlequin Duck, Histrionicus histrionicus, in Greenland
The breeding range of the Harlequin Duck (Histrionicus histrionicus) in Greenland includes West Greenland to as far north as 72º 30’ N and a few sites in East Greenland. The breeding population is guessed at a few thousand pairs. During winter Harlequin Ducks occur along the West Greenland coast between Maniitsoq and Nanortalik. The size of the winter population is unknown. As Canadian males, which have moulted in Southwest Greenland, also winter there, perhaps accompanied by females and juveniles, the numbers may be considerable. The peak period for clutch initiation seems to be mid- to late June. There is no immediate conservation concern for the small breeding population of Harlequin Ducks in Greenland. However, there is a risk from marine oil spills along coasts where congregations of non-breeding Harlequin Ducks from both Greenland and eastern Canada occur
The Lesser Black-backed Gull, Larus fuscus, in Greenland
The lesser black-backed gull (Larus fuscus) became a frequent visitor in Greenland in the mid-1980s. Breeding was confirmed in 1990, and today the species is a common breeder in at least two areas in Southwest Greenland between 60° and 66° N. The current breeding population is estimated at more than 700 pairs. Even though the colonization of Greenland by this species may be primarily the result of an increasing source population in Northwest Europe, climate change most likely will facilitate its expansion farther north in Greenland and probably also farther west to eastern Canadian coasts.Le goéland brun (Larus fuscus) est un visiteur fréquent du Groenland depuis le milieu des années 1980. La reproduction de cette espèce y a d’ailleurs été confirmée en 1990 et de nos jours, elle se reproduit régulièrement dans au moins deux régions du sud-ouest du Groenland, entre 60° et 66° N. En ce moment, la population de reproduction est évaluée à plus de 700 paires. Bien que la colonisation du Groenland par cette espèce puisse être attribuable à une population source de plus en plus grande dans le nord-ouest de l’Europe, le changement climatique facilitera vraisemblablement son foisonnement plus au nord du Groenland et probablement plus à l’ouest vers la côte est canadienne
Ross's Gulls (Rhodostethia rosea) Breeding in Greenland: A Review, with Special Emphasis on Records from 1979 to 2007
This review summarizes breeding records of Ross’s gull in Greenland with special emphasis on the period between 1979 and 2007. The review comprises both previously published records (including some published only in Danish) and unpublished reports and breeding records from 2004 and 2006. The majority of the Greenland breeding records fall into two geographically isolated areas that differ in habitat and climate: the Disko Bay area in West Greenland and the Northeast Water Polynya in Northeast Greenland. Despite the fact that antagonistic interactions with arctic terns are common, Ross’s gulls show a nest site preference for the edge of tern colonies, suggesting breeding association between these species. A general increase in breeding records in Greenland since 1978 is most likely the result of increased ornithological effort. Successful breeding has not yet been confirmed, and a Ross’s gull fledgling remains to be seen in Greenland. The Greenland breeding records suggest an opportunistic strategy in choice of breeding site among vagrant and possibly first-time breeders.Nous présentons ici un résumé des enregistrements de reproduction de la mouette rosée au Groenland, plus particulièrement pendant la période s’échelonnant entre 1979 et 2007. Cela comprend des enregistrements déjà publiés (dont certains n’ont été publiés qu’en danois) de même que des rapports inédits et des enregistrements de reproduction pour la période allant de 2004 à 2006. La majorité des enregistrements de reproduction du Groenland touchent des régions géographiquement isolées dont l’habitat et le climat diffèrent : la région de la baie Disko dans l’ouest du Groenland et la région Northeast Water Polynya dans le nord-est du Groenland. Même si des interactions antagonistes avec la sterne arctique s’avèrent courantes, la mouette rosée préfère que son nid se situe en bordure des colonies de sternes, ce qui laisse croire qu’il y a une association de reproduction entre ces espèces. Depuis 1978, l’augmentation générale des enregistrements de reproduction au Groenland est fort probablement attribuable aux efforts ornithologiques plus intenses qui ont été déployés. Toujours rien ne permet de confirmer si la reproduction est réussie, et aucune mouette rosée en bas âge n’a été repérée au Groenland. Les enregistrements de reproduction du Groenland laissent présumer l’existence d’une stratégie opportuniste en ce qui a trait au choix de lieu de reproduction chez les reproducteurs vagabonds et peut-être même chez les reproducteurs qui en sont à leur première fois
Distribution, Abundance and Reaction to Aerial Surveys of Post-breeding King Eiders (Somateria spectabilis) in Western Greenland
Moulting and post-breeding king eiders in western Greenland were surveyed in late August and early September of 1993, 1994, and 1995. We counted all eiders observed during fixed-winged aircraft flights along coastlines and offshore transects. The coastline in the survey area is roughly 13 400 km long, and our flightlines totalled approximately 16 500 km. The areas optimal for the birds were covered fully several times; in less suitable areas, only a fraction of the coastline was covered. Using the largest count for coastlines covered more than once, we counted a total of 22 980 king eiders. Large numbers of king eiders were observed at a number of remote localities on the west coast of Disko Island and in southern Upernavik. At localities considered to have frequent disturbance, few birds were observed. Highest densities were found along coasts with sandy or muddy areas at the shorelines. Overall we estimate that 30 000 to 40 000 king eiders reside in the coastal zone of western Greenland in late August. Even allowing for a high turnover rate, as different individuals may occupy the moulting areas during the extended period from July to October, this figure can account for only half of a 1950s estimate that 200 000 males and immatures were moulting in western Greenland.Fin août et début septembre en 1993, 1994 et 1995, on a dénombré les eiders à tête grise durant la mue et après la reproduction dans l'ouest du Groenland. On a compté tous les eiders aperçus durant des vols effectués par des aéronefs à voilure fixe le long de transects longeant la côte et au large. La côte de la zone étudiée fait en gros 13 400 km de long et nos vols ont couvert une distance d'environ 16 500 km. Les meilleures zones pour les oiseaux ont été complètement couvertes plusieurs fois; dans les zones leur convenant moins bien, on n'a couvert qu'une partie de la côte. En se basant sur les plus grands nombres dans le cas des lignes côtières couvertes plus d'une fois, on a compté un total de 22 980 eiders à tête grise. On a observé de grands nombres d'eiders à tête grise dans plusieurs localités reculées, sur la côte occidentale de l'île Disko et dans l'Upernavik méridional. On a observé peu d'oiseaux dans les localités considérées comme subissant des perturbations anthropiques fréquentes. Les densités les plus fortes se trouvaient sur les côtes possédant des zones sableuses ou boueuses le long du rivage. On estime que, dans l'ensemble, de 30 000 à 40 000 eiders à tête grise résident dans la zone côtière du Groenland occidental à la fin du mois d'août. Même en tenant compte du haut taux de renouvellement, car différents individus peuvent occuper les mêmes zones de mue durant la période prolongée de juillet à octobre, ce chiffre ne représente que la moitié de celui des années 1950, alors qu'on estimait à 200 000 le nombre d'oiseaux mâles et immatures qui muaient dans le Groenland occidental
Seabird Breeding Colonies in East and North Greenland: A Baseline
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
The Greenland muskox population status 1990
The indigenous population of muskoxen (Ovibos moschatus) in North and Northeast Greenland is estimated at 9 500-12 500 which is about the half of the previous estimate. This difference is mainly explained by a much better basis for estimating and to a lesser extent by a general population decrease in Northeast Greenland. The introduced population in the Kangerlussuaq (Søndre Strømfjord) area is still increasing, and is now (1990) estimated at c. 2 600. Quota based harvesting has been allowed since 1988. New populations have been introduced to the Ivittuut-area in Southwest Greenland in 1987 and to three locations in the Avanersuaq (Thule) area in Northwest Greenland in 1986. The present status of the latter populations are more or less unknown, while the Ivittuut population is thriving and has a very high rate of increase
The relative importance of physiologcal and behavioural adaptation in diving endotherms: a case study with Arctic Cormorants.
Extensive morphological and physiological adjustments are assumed to underpin the adaptations of diving birds to high thermoregulatory costs. However, the role of behavioral adaptations has received little consideration. We have assessed the relative importance of physiological and behavioral adjustments in aquatic endotherms by studying the case of the poorly insulated great cormorant (Phalacrocorax carbo) in two contrasting thermal environments: Normandy (water temperature 12°C) and Greenland (water temperature 5°C). Major differences were found in the feeding behavior of birds breeding in the two regions. Greenland birds showed a 70% reduction in time spent swimming relative to those in Normandy. Reduction in Greenland was achieved first by reducing time spent on the surface between dives and secondly by returning to land in between intensive bouts of diving. Total daily energy intake of cormorants was similar in both areas but prey capture rates in Greenland were 150% higher than those in Normandy. Our study shows that in a cold foraging environment, poorly insulated great cormorants significantly increase their foraging efficiency. To do this they rely on ecological adaptive patterns (minimization of time spent swimming in cold water and increased prey capture rates) far more than physiological adaptations (minimizing instantaneous costs). This finding supports predictions by Grémillet and Wilson (1999) that great cormorants can cope with a wide range of abiotic parameters despite their morphological handicaps, provided they can adjust their distribution to exploit dense prey patches
The Status of Glaucous Gulls Larus hyperboreus in the Circumpolar Arctic
The entire world population of the Glaucous Gull Larus hyperboreus breeds in the circumpolar Arctic. Some local populations appear to be declining significanty. In this paper, we summarize the current state of knowledge on Glaucous Gull populations and trends. The total Arctic population is estimated at approximately 171 000 breeding pairs (> 342 000 breeding individuals) distributed among at least 2700 colonies (many not documented). Population declines may be attributable to egg harvest, contaminants, or food shortages, but other factors operating outside the breeding season should not be excluded. We recommend collaborative conservation efforts that will include better population estimates in most countries, as well as standardized monitoring programs.Toute la population mondiale de goélands bourgmestres Larus hyperboreus se reproduit dans l’Arctique circumpolaire. Certaines populations locales semblent diminuer considérablement. Dans cette communication, nous résumons l’état actuel des connaissances sur les populations et les tendances concernant le goéland bourgmestre. La population arctique totale est estimée à environ 171 000 couples reproducteurs (> 342 000 individus reproducteurs) répartis dans au moins 2 700 colonies (dont grand nombre n’ont pas été consignées). Les déclins de population peuvent être attribuables à la récolte des œufs, aux contaminants ou aux pénuries de nourriture, bien qu’il ne faille pas exclure d’autres facteurs ne se rapportant pas à la saison de reproduction. Nous recommandons des efforts de conservation communs qui comprendront de meilleures estimations de population dans la plupart des pays de même que des programmes de surveillance normalisés
Effects of oil and oil burn residues on seabird feathers
It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified. To protect seabirds, a rapid removal of oil is crucial and in situ burning could be an efficient method. In the present work exposure effects of oil and burn residue in different doses was studied on seabird feathers from legally hunted Common eider (Somateria mollissima) by examining changes in total weight of the feather and damages on the microstructure (Amalgamation Index) of the feathers before and after exposure. The results of the experiments indicate that burn residues from in situ burning of an oil spill have similar or larger fouling and damaging effects on seabird feathers, as compared to fresh oil
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