Thick-billed murres and black guillemots in the Barrow Strait area, N.W.T., during spring: distribution and habitat use

1979 ◽  
Vol 57 (9) ◽  
pp. 1789-1802 ◽  
Author(s):  
Michael S. W. Bradstreet
Keyword(s):  
Habitat Use ◽  
Canadian Arctic ◽  
Open Water ◽  
High Arctic ◽  
Marine Water ◽  
Uria Lomvia ◽  
Cepphus Grylle ◽  
Aerial Surveys ◽  
Landfast Ice ◽  
Small Cracks

During the "spring" periods of 1974–1976, Uria lomvia and Cepphus grylle in the central Canadian Arctic were concentrated in the Barrow Strait area. Aerial surveys indicated that densities of both species were higher in interface habitats (i.e. along boundaries of land or ice and marine water) than in areas of open water distant from coasts or landfast ice. Murres occurred in higher densities along offshore than along coastal landfast ice edges; guillemots showed no preference between these two habitats. Guillemots, but not murres, occurred in small cracks in landfast ice. The overall preference of murres and guillemots for interface habitats was compared with the results of two other studies of the distribution of these alcids in high arctic areas.

Diet and foraging ecology of Black Guillemots in northeastern Hudson Bay

1987 ◽  
Vol 65 (5) ◽  
pp. 1257-1263 ◽  
Author(s):  
D. K. Cairns
Keyword(s):  
Foraging Ecology ◽  
Canadian Arctic ◽  
Open Water ◽  
Hudson Bay ◽  
Boreogadus Saida ◽  
Foraging Habitat ◽  
Decapod Crustaceans ◽  
Cepphus Grylle ◽  
Landfast Ice ◽  
Eastern Canadian Arctic

I examined diet and foraging habitat selection by Black Guillemots (Cepphus grylle) in the eastern Canadian arctic. Birds fed on fish (Boreogadus saida, Stichaeus punctatus, Eumesogrammus praecisus) and mysid, amphipod, and decapod crustaceans. Guillemots concentrated at landfast ice edges early in the breeding season. Open-water foraging occurred principally in waters 10–30 m deep within 13 km of breeding colonies. Guillemots were aggregated on the water, but their distributions were not correlated with those of schooling prey. Guillemots feeding in open water obtained much of their food on the bottom, but some prey was likely taken during transit to and from the bottom.

scholarly journals A First Count of Thick-billed Murres (Uria lomvia) and Black-legged Kittiwakes (Rissa tridactyla) Breeding on Bylot Island

2017 ◽  
Vol 131 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Anthony J. Gaston ◽  
Marc-Andre Cyr ◽  
Kieran O'Dononvan
Keyword(s):  
High Resolution ◽  
Image Quality ◽  
National Park ◽  
Canadian Arctic ◽  
High Arctic ◽  
Correction Factors ◽  
Uria Lomvia ◽  
Rissa Tridactyla ◽  
Canadian Population ◽  
Bylot Island

Bylot Island, part of Sirmilik National Park, supports two major breeding colonies of intermingled Thick-billed Murres (Uria lomvia) and Black-legged Kittiwakes (Rissa tridactyla): at Cape Hay near the northwest tip and at Cape Graham Moore at the opposite end of the island. Although the size of these colonies has been estimated previously, there is no information on how the estimates were made, except for Thick-billed Murres at Cape Hay in 1977, when the numbers were based on sampling only about 30% of the colony. In 2013, high-resolution digital photographs of the whole area of both colonies were taken in July, when most birds were probably incubating eggs. Individual birds were counted on the photographs, and the numbers were corrected for image quality and converted to numbers of breeding pairs based on correction factors from another High Arctic colony. Our estimates were similar to those from earlier years for kittiwakes at Cape Graham Moore and for murres at Cape Hay, but suggested that numbers of murres were higher than previously thought at Cape Graham Moore, while numbers of kittiwakes were lower at Cape Hay. The overall total for the Canadian population of Thick-billed Murres was unaffected by these changes, but the total number of Black-legged Kittiwakes nesting in the Canadian Arctic may be 20% lower than previously thought.

Thick-billed murres and black guillemots in the Barrow Strait area, N.W.T., during spring: diets and food availability along ice edges

1980 ◽  
Vol 58 (11) ◽  
pp. 2120-2140 ◽  
Author(s):  
Michael S. W. Bradstreet
Keyword(s):  
Water Column ◽  
Food Availability ◽  
Dry Weight ◽  
Boreogadus Saida ◽  
Associated Fauna ◽  
Uria Lomvia ◽  
Arctic Cod ◽  
Cepphus Grylle ◽  
Sea Bottom ◽  
Landfast Ice

From 5 June to 4 July 1976, I collected 98 thick-billed murres (Uria lomvia) and 47 black guillemots (Cepphus grylle) at ice edges in Barrow Strait, N.W.T., for diet studies. Alcids were collected at coastal ice edges and at the edges of landfast ice farther offshore; in both habitats food availability was also studied. At coastal ice edges, murre diet was dominated by Arctic cod (Boreogadus saida, 14% of dry weight biomass) and the amphipod Onisimus litoralis (18%); guillemot diet was dominated by cod (99%), decapods (0.4%), and amphipods (0.2%). At offshore ice edges murres took cod (96%), Parathemisto (2%), and Onisimus glacialis (2%); guillemots took cod (54%), O. glacialis (35%), and Apherusa glacialis (5%). Morisita's overlap values showed that diets of these two alcids were more similar at offshore than at coastal ice edges and that there were considerable habitat-related differences in diet. Data on food availability suggested that at offshore ice edges, murres were feeding in the water column and at the undersurface of the landfast ice; guillemots fed almost solely at the ice undersurface. At coastal ice edges, both alcids were probably feeding at the ice undersurface and on the sea bottom; in addition, murres fed in the water column. The importance of epontic (= ice-associated) fauna in the diets of alcids during spring is discussed.

scholarly journals Diversity and Keratin Degrading Ability of Fungi Isolated from Canadian Arctic Marine Bird Feathers

ARCTIC ◽  
2019 ◽  
Vol 72 (4) ◽  
pp. 347-359
Author(s):  
Brent M. Robicheau ◽  
Sarah J. Adams ◽  
Jennifer F. Provencher ◽  
Gregory J. Robertson ◽  
Mark L. Mallory ◽  
...  
Keyword(s):  
Multiple Correspondence Analysis ◽  
Canadian Arctic ◽  
Fungal Species ◽  
Somateria Mollissima ◽  
Uria Lomvia ◽  
King Eider ◽  
Rissa Tridactyla ◽  
Cepphus Grylle ◽  
Black Guillemot ◽  
Low Arctic

We present the first records of fungi associated with feathers from seabirds and sea ducks in the Canadian Arctic and sub-Arctic. Birds sampled in Nunavut and Newfoundland (Canada) included the Common Eider (Somateria mollissima), King Eider (S. spectabilis), Black-legged Kittiwake (Rissa tridactyla), Northern Fulmar (Fulmarus glacialis), Glaucous Gull (Larus hyperboreus), Black Guillemot (Cepphus grylle), and Thick-billed Murre (Uria lomvia). In total 19 fungal species were cultured from feathers, identified using ITS rDNA barcoding, and screened for their ability to degrade keratin using a keratin azure assay. Our results indicate that 1) of the 19 isolates, 74% were ascomycetes, while the remaining 26% were basidiomycetes (yeasts); 2) 21% of the ascomycete isolates demonstrated keratinolytic activity (a known pathogenicity factor for fungi that may potentially be harmful to birds); 3) the largest number of fungi were cultured from the sampled Thick-billed Murre; and 4) based on a multiple correspondence analysis, there is some indication that both the King Eider and the Thick-billed Murre collected in the low Arctic had distinct fungal communities that were different from each other and from the other birds sampled. Although our sample sizes were small, initial trends in point (4) do demonstrate that additional study is merited to assess whether the fungal community differences are influenced by variation in the known ecologies of the avian hosts and fungi identified.

scholarly journals On the Thermal Regime of a High-Arctic Valley Glacier

1976 ◽  
Vol 16 (74) ◽  
pp. 119-133 ◽  
Author(s):  
Fritz Müller
Keyword(s):  
Thermal Regime ◽  
Energy Input ◽  
Canadian Arctic ◽  
High Arctic ◽  
Canadian Arctic Archipelago ◽  
Valley Glacier ◽  
Drilling Technique ◽  
Percolation Zone ◽  
Mean Annual Air Temperature ◽  
Upper Boundary

AbstractThe 10 m temperatures were measured over several years at 16 sites on the White Glacier (lat. 80° N.), Axel Heiberg Island, Canadian Arctic Archipelago. At three sites deep profiles were made using a new drilling technique, reaching a maximum depth of 280 m. Large differences in the 10 m temperatures between locations and from year to year were observed. The deviations of these temperatures from the almost isothermal mean annual air temperature over the glacier are discussed. The heating effect of the melt water in the lower percolation zone was found to be very important. A conceptual model is developed to assess the influence of these irregularities in the energy input at the upper boundary on the thermal regime of the entire glacier. So far a quantitative analysis has been made only for the relatively simple 30 m temperature profile measured on the tongue of the glacier.

The migratory behaviour of narwhals (Monodon monoceros)

2003 ◽  
Vol 81 (8) ◽  
pp. 1298-1305 ◽  
Author(s):  
Mads Peter Heide-Jørgensen ◽  
Rune Dietz ◽  
Kristin L Laidre ◽  
Pierre Richard ◽  
Jack Orr ◽  
...  
Keyword(s):  
Open Water ◽  
High Arctic ◽  
Early Summer ◽  
Canadian High Arctic ◽  
Baffin Bay ◽  
Bay Area ◽  
Monodon Monoceros ◽  
Migratory Routes ◽  
Somerset Island ◽  
Wintering Ground

Sixteen female narwhals (Monodon monoceros) were tracked by satellite in 2000 and 2001 from their summering ground near Somerset Island in the Canadian High Arctic to their wintering ground in central Baffin Bay. The wintering ground location was spatially discrete from another narwhal wintering ground in southern Baffin Bay. Area extent of the summering ground was approximately 9464 km2 and area extent of the wintering ground was 25 846 km2. Two of the narwhals were tracked for more than 12 consecutive months. These whales used three focal areas between their spring and autumn migration: a coastal area in the open-water season in August in the Canadian High Arctic, a wintering area from November through April in the consolidated pack ice of Baffin Bay, and an early summer area in front of the receding fast ice edge in Lancaster Sound. The whales showed remarkable site fidelity to summering grounds and had specific migratory routes that followed sea ice formation and recession.

scholarly journals The littoral zone of polar lakes: inshore–offshore contrasts in an ice-covered High Arctic lake

2020 ◽  
pp. 1-24
Author(s):  
Paschale N. Bégin ◽  
Milla Rautio ◽  
Yukiko Tanabe ◽  
Masaki Uchida ◽  
Alexander I. Culley ◽  
...  
Keyword(s):  
Light Availability ◽  
Sharp Decrease ◽  
Open Water ◽  
High Arctic ◽  
Early Summer ◽  
Fatty Acid Profiles ◽  
Canadian High Arctic ◽  
Abrupt Increase ◽  
Horizontal Gradients

In ice-covered polar lakes, a narrow ice-free moat opens up in spring or early summer, and then persists at the edge of the lake until complete ice loss or refreezing. In this study, we analyzed the horizontal gradients in Ward Hunt Lake, located in the Canadian High Arctic, and addressed the hypothesis that the transition from its nearshore open-water moat to offshore ice-covered waters is marked by discontinuous shifts in limnological properties. Consistent with this hypothesis, we observed an abrupt increase in below-ice concentrations of chlorophyll a beyond the ice margin, along with a sharp decrease in temperature and light availability and pronounced changes in benthic algal pigments and fatty acids. There were higher concentrations of rotifers and lower concentrations of viruses at the ice-free sampling sites, and contrasts in zooplankton fatty acid profiles that implied a greater importance of benthic phototrophs in their inshore diet. The observed patterns underscore the structuring role of ice cover in polar lakes. These ecosystems do not conform to the traditional definitions of littoral versus pelagic zones but instead may have distinct moat, ice-margin, and ice-covered zones. This zonation is likely to weaken with ongoing climate change.

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