39 research outputs found

    Polar Research in Tromsø 2003

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    A revision of the fossil genus Miocepphus and other Miocene Alcidae (Aves: Charadriiformes) of the Western North Atlantic Ocean

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    This study reviews and describes all known fossils of Alcidae from the Miocene of the western North Atlantic. Because the majority of alcid fossils recovered from Miocene sediments are allied with the genus Miocepphus Wetmore, 1940, the genus is revised here. Three new species of Miocepphus are described: Miocepphus bohaskai and Miocepphus blowi from the Early to Late Miocene, and Miocepphus mergulellus of uncertain Neogene age but probably Miocene. A new genus and species, Pseudocepphus teres, from the Middle and Late Miocene, has uncertain relationships within the Alcinae (a clade comprising Miocepphus, Alle, Uria, Alca and Pinguinus). The genus Alca is also reported from Late Miocene sediments. The newly recognised presence of three genera of the Alcinae in the Miocene of the North Atlantic indicates that the diversity of the subfamily was considerably greater than was evident previously. Miocepphus may be regarded as ancestral to modern Alcinae. The Alcinae as a group was well established in the Early Miocene, indicating that the divergence of the family Alcidae predates 20 Ma. The divergence of Uria and Alca predates 10 M

    The Status of marine birds breeding in the Barents Sea region

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    Land cover in Norway based on an area frame survey of vegetation types

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    The Norwegian area frame survey of land cover and outfield land resources (AR18X18), completed in 2014, provided unbiased statistics of land cover in Norway. The article reports the new statistics, discusses implications of the data set, and provides potential value in terms of research, management, and monitoring. A gridded sampling design for 1081 primary statistical units of 0.9 km2 at 18 km intervals was implemented in the survey. The plots were mapped in situ, aided by aerial photos, and all areas were coded following a vegetation type system. The results provide new insights into the cover and distribution of vegetation and land cover types. The statistic for mire and wetlands, which previously covered 5.8%, has since been corrected to 8.9%. The survey results can be used for environmental and agricultural management, and the data can be stratified for regional analyses. The survey data can also serve as training data for remote sensing and distribution modelling. Finally, the survey data can be used to calibrate vegetation perturbations in climate change research that focuses on atmospheric–vegetation feedback. The survey documented novel land cover statistics and revealed that the national cover of wetlands had previously been underestimated.publishedVersio

    A Phylogenetic Analysis of Extinct and Extant Pan-Alcidae (Charadriiformes: Aves)

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    Pan-Alcidae is a clade of birds consisting of the crown-clade Alcidae and the extinct Mancallinae. They include 24 extant species, 1 recently extinct species, and a fossil record extending as far back as the Eocene. All extinct and extant Pan-alcid diversity exhibit an exclusively Holarctic distribution with the majority of extant diversity found in the Pacific. The relationships of the Pan-Alcidae have been a long-standing subject of debate. Early systematic hypotheses placed Pan-Alcidae as close relatives of various water birds, however modern phylogenetic hypotheses have supported their placement within Charadriiformes. Their exact placement within Charadriiformes has yielded multiple hypotheses with further difficulty found in resolving the relationships within the clade itself. Until recently, most work on Pan-Alcidae systematics focused primarily on extant diversity, neglecting to include data from their robust fossil record. By performing molecular, morphological, and combined analyses of Pan-Alcidae and a dense outgroup of Charadriiformes representatives, this study proposes hypotheses for the relationships of extinct and extant species. A novel hypothesis is proposed for the placement of the extinct Aethia rossmoori among the Brachyramphus. This relationship makes A. rossmoori the earliest known fossil from this lineage and extends the Brachyramphus lineage’s fossil record into the Late Miocene. Additionally, all analyses support the placement of Pseudocepphus teres as sister to the Cepphus extending their temporal and geographic range to include the Middle to Late Miocene Atlantic. A Bayesian total-evidence dating analysis estimated a divergence of Alcidae from other Charadriiformes during the Early Eocene. The divergence of the major Alcidae clades (the Fraterculinae and Alcinae) was estimated to have occurred during the Oligocene. Of 29 fossil Pan-Alcidae species, 6 were inferred to be sampled ancestors. Notably, Mancalla cedrosensis was inferred to be a direct ancestor of Mancalla californiensis providing a novel hypothesis for their previously supported close relationship

    Molecular phylogenetics of the Bombycillidae and Limosa (Scolopacidae)

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    Thesis (M.S.) University of Alaska Fairbanks, 2000The Bombycillidae and their allies and Limosa and their allies represent ideal groups in which to use phylogenetic reconstruction to examine historic patterns of intercontinental colonization between North America and Eurasia and the role of intercontinental colonization in diversification. Molecular phylogenetic reconstruction suggests a Neotropical origin for the Bombycillidae and a subsequent colonization of Eurasia via Beringia, which is an exception to the normal pattern of a faunal exchange between these two continents. Molecular and morphological phylogenetic reconstructions suggest most relationships within Limosa are polytomous. Further analysis of the polytomous relationships indicates that the species of Limosa speciated relatively rapidly in relation to the average age of the lineages, and that intercontinental colonization probably played an important role in their diversification

    A supertree approach to shorebird phylogeny

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    BACKGROUND: Order Charadriiformes (shorebirds) is an ideal model group in which to study a wide range of behavioural, ecological and macroevolutionary processes across species. However, comparative studies depend on phylogeny to control for the effects of shared evolutionary history. Although numerous hypotheses have been presented for subsets of the Charadriiformes none to date include all recognised species. Here we use the matrix representation with parsimony method to produce the first fully inclusive supertree of Charadriiformes. We also provide preliminary estimates of ages for all nodes in the tree. RESULTS: Three main lineages are revealed: i) the plovers and allies; ii) the gulls and allies; and iii) the sandpipers and allies. The relative position of these clades is unresolved in the strict consensus tree but a 50% majority-rule consensus tree indicates that the sandpiper clade is sister group to the gulls and allies whilst the plover group is placed at the base of the tree. The overall topology is highly consistent with recent molecular hypotheses of shorebird phylogeny. CONCLUSION: The supertree hypothesis presented herein is (to our knowledge) the only complete phylogenetic hypothesis of all extant shorebirds. Despite concerns over the robustness of supertrees (see Discussion), we believe that it provides a valuable framework for testing numerous evolutionary hypotheses relating to the diversity of behaviour, ecology and life-history of the Charadriiformes

    Contrasting body burdens of organohalogenated contaminants in two Arctic glaucous gull Larus hyperboreus populations in relation to their dietary ecology

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    This study compared body burdens of organohalogenated contaminants (OHCs) between glaucous gull populations from Bjørnøya and Kongsfjorden, Svalbard and if OHC levels was influenced by their dietary ecology and biological variables (body condition index and sex). To do so, blood from 112 adult glaucous gulls were sampled during the breeding seasons of 2015 until 2019 in Bjørnøya and Kongsfjorden. We measured plasma concentrations of OHCs including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and perfluorinated alkylated substances (PFASs). Feather stable isotopes of nitrogen (δ15N) and carbon (δ13C) were analyzed to indicate trophic level and feeding habitat, respectively. Body burdens of OHCs differed significantly between the two populations for all 5 sampling years. Overall, the population at Bjørnøya had plasma concentrations of OHCs 5.3 times higher than the Kongsfjorden population. The most quantitatively abundant contaminants found in the glaucous gulls were ΣPCBs and ΣPFASs in Bjørnøya and ∑PCBs in Kongsfjorden. No differences in relative trophic position between both breeding populations were reported although Kongsfjorden individuals varied significantly in δ15N across sampling years, while Bjørnøya individuals remained stable over time. In addition, we highlighted no relationship between plasma OHCs and feather δ15N (trophic position) although the lack of association might be due to both tissues (i.e blood and feathers) reflecting different time scales. Only ΣPFSAs and ΣPFCAs showed a positive relationship with δ13C, suggesting that feeding habitat, more than trophic position, might explain variance in contaminant exposure
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