Phenotypic Variation among Thick-billed Murres from Colonies in Hudson Strait

Thick-billed Murres (Uria lomvia) breeding in the Canadian Arctic are restricted to a small number of colonies, all comprising more that 10,000 pairs. Five of these colonies are scattered through Hudson Strait. We collected adult breeders at three of the colonies - Digges Island, Hantzsch Island, and Akpatok Island - and compared wing and bill measurements and body weights to look for inter-colony differences. Significant inter-colony differences were present for all measurements and a discriminant function analysis showed that some individuals fall completely outside the range of variation for the other colonies. Because of the presence of the Laurentide ice-sheet over Hudson Strait, the present colony sites could not have been occupied for more than 10,000 years. If the observed differences reflect differences in genotype then their evolution must have occurred over this period.Key words: Thick-billed murre, Uria lomvia, phenotypic variation, Hudson Strait, evolutionMots clés: Marmettes de Brunnïch, Uria lomvia, variation des phénotypes, détroit d'Hudson, évolutio

The Distribution of Larger Species of Birds Breeding on the Coasts of Foxe Basin and Northern Hudson Bay, Canada

Aerial surveys of large birds on the coasts of Foxe Basin and northern Hudson Bay were carried out in late June and early July in 1979, 1983 and 1984. Greatest numbers of birds were seen along low-lying coasts backed by wet lowland tundra, particularly where these merged into extensive inter-tidal flats. These areas have emerged from the sea only during the past 2000 years. Even in areas of wet lowland tundra, all species except jaegers appeared to be patchy in their distribution, the patches being unrelated to obvious features of the habitat. We suggest that breeding habitat for many species is not completely occupied, at least in normal breeding seasons. We propose that statutory protection be extended to all or parts of Prince Charles and Air Force islands, which support high numbers of several species and are currently unprotected.Key words: arctic birds, coastal breeding, aerial surveys, Foxe Basin, Hudson BayMots clés: oiseaux arctiques, nidification côtière, inventaires aériens, bassin Foxe, baie d'Hudso

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

The Dark Energy Survey : more than dark energy – an overview

This overview paper describes the legacy prospect and discovery potential of the Dark Energy Survey (DES) beyond cosmological studies, illustrating it with examples from the DES early data. DES is using a wide-field camera (DECam) on the 4 m Blanco Telescope in Chile to image 5000 sq deg of the sky in five filters (grizY). By its completion, the survey is expected to have generated a catalogue of 300 million galaxies with photometric redshifts and 100 million stars. In addition, a time-domain survey search over 27 sq deg is expected to yield a sample of thousands of Type Ia supernovae and other transients. The main goals of DES are to characterize dark energy and dark matter, and to test alternative models of gravity; these goals will be pursued by studying large-scale structure, cluster counts, weak gravitational lensing and Type Ia supernovae. However, DES also provides a rich data set which allows us to study many other aspects of astrophysics. In this paper, we focus on additional science with DES, emphasizing areas where the survey makes a difference with respect to other current surveys. The paper illustrates, using early data (from ‘Science Verification’, and from the first, second and third seasons of observations), what DES can tell us about the Solar system, the Milky Way, galaxy evolution, quasars and other topics. In addition, we show that if the cosmological model is assumed to be +cold dark matter, then important astrophysics can be deduced from the primary DES probes. Highlights from DES early data include the discovery of 34 trans-Neptunian objects, 17 dwarf satellites of the Milky Way, one published z > 6 quasar (and more confirmed) and two published superluminous supernovae (and more confirmed)