The breeding behavior of Atlantic walruses, Odobenus rosmarus rosmarus, in the Canadian High Arctic

The breeding behavior of Atlantic walruses, Odobenus rosmarus rosmarus, overwintering at the Dundas Island polynya (76 °09′N, 94 °52′W) in the Canadian High Arctic was studied from 1981 to 1990. Approximately 25–65 walruses frequented the polynya area each winter; their distribution was determined by sea-ice features (e.g., thin annual ice, cracks) that ensured easy access to open water. The mating system of walruses breeding in the area is best described as female-defense polygyny. A large mature male had exclusive access to a herd of walruses containing several females for 1–5 days at a time. Although there were numerous males in the polynya capable of attending a herd during the breeding season, one or two males spent significantly more time with a herd. It was not evident that female preference was important in determining which male became the attending male. When attending a herd, a male continuously repeated a complex, stereotyped underwater song. Other sexually mature males in the area behaved as silent herd members, vocal satellite males, or, in some cases, both. The small number of walruses at the polynya, the sedentary nature of the population due to ice conditions, and the inherent gregariousness of female walruses appear to be important factors influencing the evolution of social behavior and the mating system in walruses

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The migratory behaviour of narwhals (Monodon monoceros)

Canadian Journal of Zoology ◽

10.1139/z03-117 ◽

2003 ◽

Vol 81 (8) ◽

pp. 1298-1305 ◽

Cited By ~ 51

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.

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

Arctic Science ◽

10.1139/as-2020-0026 ◽

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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Abundance of Atlantic walrus in Western Nares Strait, Baffin Bay Stock, during summer

NAMMCO Scientific Publications ◽

10.7557/3.2611 ◽

2014 ◽

Vol 9 ◽

pp. 123 ◽

Cited By ~ 5

Author(s):

Robert EA Stewart ◽

Erik W Born ◽

Rune Dietz ◽

Mads Peter Heide-Jørgensen ◽

Frank Farsø Rigét ◽

...

Keyword(s):

Water Surface ◽

Open Water ◽

Ellesmere Island ◽

Baffin Bay ◽

Nares Strait ◽

The North ◽

North Water Polynya ◽

Odobenus Rosmarus ◽

North Water ◽

Odobenus Rosmarus Rosmarus

Atlantic walruses (Odobenus rosmarus rosmarus) belonging to the Baffin Bay subpopulation occur year round in the North Water polynya (NOW) between NW Greenland and eastern Ellesmere Island (Canada). They are hunted for subsistence purposes by residents of the Qaanaaq area (NW Greenland) bordering the NOW to the east and by Canadian Inuit at the entrance to Jones Sound in Nunavut. During the open-water period NW Greenland is virtually devoid of walruses which concentrate along eastern and southern Ellesmere Island at this time of the year. To determine the abundance of walruses in the NOW area, aerial surveys were conducted in August of 1999, 2008, and 2009. In July 2009, nine satellite-linked transmitters were deployed in nearby Kane Basin. Surveys on 9 and 20 August 2009 along eastern Ellesmere Island were the most extensive and were augmented with concomitant data on haul-out and at water surface activity from three (1 F, 2 M) of the nine tags that were still functioning. We therefore focus on the 2009 surveys. Walruses were observed on the ice and in water primarily in Buchanan Bay and Princess Marie Bay where the remaining functional tags were located. The Minimum Counted population (MCP) was 571 on 20 August. Adjusting the MCP of walruses on ice for those not hauled out, the estimate of abundance of walruses in the Baffin Bay stock was 1,251(CV=1.00, 95% CI = 1,226) when adjusted by the proportion of tags ‘dry’ at the time of the survey and 1,249 (CV=1.12, 95% CI = 1,370) when adjusted by the average time tags were dry. The surveys did not cover all potential walrus summering habitat along eastern Ellesmere Island and are negatively biased to an unknown degree.

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Stock discrimination of Atlantic walrus (Odobenus rosmarus rosmarus) in the eastern Canadian Arctic using lead isotope and element signatures in teeth

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-155 ◽

1999 ◽

Vol 56 (1) ◽

pp. 105-112 ◽

Cited By ~ 19

Author(s):

P M Outridge ◽

R EA Stewart

Keyword(s):

Canadian Arctic ◽

Isotope Ratios ◽

High Arctic ◽

Trace Element Composition ◽

Pb Isotope ◽

Foxe Basin ◽

Stock Discrimination ◽

Odobenus Rosmarus ◽

Odobenus Rosmarus Rosmarus ◽

Atlantic Walrus

Atlantic walrus (Odobenus rosmarus rosmarus) harvested from three regions of the Canadian Arctic, and by different communities within two of those regions, were distinguished using the stable Pb isotope or trace element composition of their tooth cementum. Walrus from Foxe Basin (Igloolik, Hall Beach), the High Arctic (Grise Fiord, Resolute Bay), and eastern Hudson Bay (Akulivik, Inukjuak) were each characterized by specific combinations of Pb isotope ratios and Co concentrations, and we conclude that they represent different regional stocks. Walrus landed at Akulivik and Inukjuak were further discriminated by significant differences in 208Pb/207Pb, even though the communities are only 250 km apart. There was more overlap between walrus from Igloolik and Hall Beach, which are 80 km apart, but significant differences between sites in Pb isotope ratios and in concentrations of V, Zn, and Mo suggested that more than one Foxe Basin stock was being harvested. Particularly at Hall Beach, the herds contained a few individuals with isotope ratios significantly different from the rest of the population. These "outliers" may represent either immigrants from other geological provinces or animals caught in other areas. Further investigation of the outliers could provide information regarding hunting patterns, walrus home ranges, and the rates and demographics of interstock migrations.

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Investigating the anomalous sea-ice conditions in the Canadian High Arctic (Queen Elizabeth Islands) during summer 1998

Annals of Glaciology ◽

10.3189/172756401781818761 ◽

2001 ◽

Vol 33 ◽

pp. 507-512 ◽

Cited By ~ 27

Author(s):

Sharon Jeffers ◽

Tom A. Agnew ◽

Bea Taylor Alt ◽

Roger de Abreu ◽

Steve McCourt

Keyword(s):

Time Series ◽

Sea Ice ◽

High Arctic ◽

Canadian High Arctic ◽

Sea Ice Extent ◽

Ice Melt ◽

Digital Database ◽

Ice Conditions ◽

Fast Ice ◽

Thermal Preconditioning

AbstractThe Queen Elizabeth Islands of the Canadian Arctic Archipelago exhibit one of the most complex sea-ice regimes in the Northern Hemisphere. Time series of minimum monthly passive-microwave sea-ice area (1979−98), minimum sea-ice extent, melting degree-days (1961−98) and minimum sea ice from the new Canadian Ice Service digital database (1968−98) are examined. The extreme nature of the amount of sea-ice melt in the summers of 1998 and 1962 is evident in these time series. The 38 year record of minimum ice, to date, shows no significant trend. Details of the sea-ice behavior during summer 1998 were then examined within 13 individual sea-ice regimes. The multi-year fast-ice plugs in both Sverdrup Channel and Nansen Sound broke up and became truly mobile in 1998. Discussion focuses on the areas surrounding the multi-year plugs, relating sea-ice conditions to weather. Results emphasize the importance of the timing of synoptic events in combination with strong thermal preconditioning in determining the sea-ice conditions in this area during summer 1998.

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A catch history for Atlantic walruses (Odobenus rosmarus rosmarus) in the eastern Canadian Arctic

NAMMCO Scientific Publications ◽

10.7557/3.3065 ◽

2014 ◽

Vol 9 ◽

pp. 219 ◽

Cited By ~ 8

Author(s):

D Bruce Stewart ◽

Jeff W Higdon ◽

Randall R Reeves ◽

Robert EA Stewart

Keyword(s):

Canadian Arctic ◽

High Arctic ◽

Bowhead Whale ◽

Steady Increase ◽

Odobenus Rosmarus ◽

Inuit Population ◽

Minimum Numbers ◽

Over Time ◽

Eastern Canadian Arctic ◽

Odobenus Rosmarus Rosmarus

Knowledge of changes in abundance of Atlantic walruses (Odobenus rosmarus rosmarus) in Canada is important for assessing their current population status. This catch history collates available data and assesses their value for modelling historical populations to inform population recovery and management. Pre-historical (archaeological), historical (e.g., Hudson Bay Company journals) and modern catch records are reviewed over time by data source (whaler, land-based commercial, subsistence etc.) and biological population or management stock.Direct counts of walruses landed as well as estimates based on hunt products (e.g., hides, ivory) or descriptors (e.g., Peterhead boatloads) support a minimum landed catch of over 41,300 walruses in the eastern Canadian Arctic between 1820 and 2010. Little is known of Inuit catches prior to 1928, despite the importance of walruses to many Inuit groups for subsistence. Commercial hunting from the late 1500s to late 1700s extirpated the Atlantic walrus from Quebec and the Atlantic Provinces, but there was no commercial hunt for the species in the Canadian Arctic until ca. 1885. As the availability of bowhead whale (Balaena mysticetus) declined, whalers increasingly turned to hunting other species, including walruses. Modest numbers (max. 278/yr) were taken from the High Arctic population in the mid-1880s and large catches (up to 1400/yr) were often taken from the Central Arctic population from 1899 -1911, while the Foxe Basin stock (Central Arctic population) and Low Arctic population were largely ignored by commercial hunters. Land-based traders (ca. 1895-1928) continued the commercial hunt until regulatory changes in 1928 reserved walruses for Inuit use. Since 1950, reported walrus catches have been declining despite a steady increase in the Inuit population. Effort data are needed to assess whether lower catches stem from declining hunter effort or decreased walrus abundance. The recent take of walruses by sport hunting has been small (n=141, 1995-2010), sporadic and local.These landed catch estimates indicate the minimum numbers of walruses removed but do not account for under-reporting or lost animals that were killed but were not secured. Unreported and lost animals may represent a significant fraction of the total removals and must be considered in any modelling exercise. The sources, quality and completeness of the catch data vary widely over time and space and between the different hunt types. This variability confounds interpretation and contributes to the uncertainty that needs to be incorporated into any modelling. The data on Inuit subsistence catches before ca. 1928 are particularly fragmentary and uncertain.

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Diet dichotomy between two migrant seabirds breeding near a high Arctic polynya

Royal Society Open Science ◽

10.1098/rsos.160982 ◽

2017 ◽

Vol 4 (3) ◽

pp. 160982 ◽

Cited By ~ 3

Author(s):

Isabeau Pratte ◽

Kelly A. Boadway ◽

Shanti E. Davis ◽

Mark Maftei ◽

Mark L. Mallory

Keyword(s):

Open Water ◽

High Arctic ◽

Canadian High Arctic ◽

Long Distance ◽

Sterna Paradisaea ◽

Xema Sabini ◽

Reliable Source ◽

Dietary Niche ◽

Sabine’S Gull ◽

Ground Nesting

High Arctic polynyas are predictable areas of open water, which offer long-distance migrant seabirds a reliable source of food during a period when they have to replenish and accumulate energy for reproduction. Investigating the interaction between species nesting sympatrically in the vicinity of polynyas should provide insights into the role that such oceanographic features play for pre-breeding seabirds. We used stable isotopes (δ 13 C and δ 15 N) to compare the diet of two ground-nesting seabirds, Sabine's gull ( Xema sabini ) and Arctic tern ( Sterna paradisaea ), nesting on an island adjacent to a recurring polynya in the Canadian high Arctic in 2008 and 2009. We show that, unlike Arctic terns, the diet of Sabine's gulls appears to include a non-negligible amount of terrestrially derived prey during early incubation, and that overall both species segregate their dietary niche during pre-laying and early incubation.

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