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

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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Breeding biology of Sabine’s gull (Xema sabini) in the Canadian high Arctic

Polar Biology ◽

10.1007/s00300-011-1079-x ◽

2011 ◽

Vol 35 (3) ◽

pp. 335-344 ◽

Cited By ~ 8

Author(s):

Mark L. Mallory ◽

Kelly A. Boadway ◽

Shanti E. Davis ◽

Mark Maftei

Keyword(s):

High Arctic ◽

Breeding Biology ◽

Canadian High Arctic ◽

Xema Sabini ◽

Sabine’S Gull

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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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Assessing regional populations of ground-nesting marine birds in the Canadian High Arctic

Polar Research ◽

10.3402/polar.v34.25055 ◽

2015 ◽

Vol 34 (1) ◽

pp. 25055 ◽

Cited By ~ 14

Author(s):

Mark Maftei ◽

Shanti E. Davis ◽

Mark L. Mallory

Keyword(s):

High Arctic ◽

Canadian High Arctic ◽

Marine Birds ◽

Ground Nesting

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

Canadian Journal of Zoology ◽

10.1139/z96-103 ◽

1996 ◽

Vol 74 (5) ◽

pp. 897-911 ◽

Cited By ~ 27

Author(s):

B. Sjare ◽

I. Stirling

Keyword(s):

Mating System ◽

Open Water ◽

High Arctic ◽

Easy Access ◽

Breeding Behavior ◽

Canadian High Arctic ◽

Odobenus Rosmarus ◽

Ice Conditions ◽

Female Defense Polygyny ◽

Odobenus Rosmarus Rosmarus

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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Tracking of Arctic terns Sterna paradisaea reveals longest animal migration

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0909493107 ◽

2010 ◽

Vol 107 (5) ◽

pp. 2078-2081 ◽

Cited By ~ 281

Author(s):

Carsten Egevang ◽

Iain J. Stenhouse ◽

Richard A. Phillips ◽

Aevar Petersen ◽

James W. Fox ◽

...

Keyword(s):

High Arctic ◽

The Arctic ◽

Migration Routes ◽

Long Distance ◽

Seasonal Movement ◽

The North ◽

Breeding Populations ◽

Flight Costs ◽

Sterna Paradisaea ◽

And Performance

The study of long-distance migration provides insights into the habits and performance of organisms at the limit of their physical abilities. The Arctic tern Sterna paradisaea is the epitome of such behavior; despite its small size (<125 g), banding recoveries and at-sea surveys suggest that its annual migration from boreal and high Arctic breeding grounds to the Southern Ocean may be the longest seasonal movement of any animal. Our tracking of 11 Arctic terns fitted with miniature (1.4-g) geolocators revealed that these birds do indeed travel huge distances (more than 80,000 km annually for some individuals). As well as confirming the location of the main wintering region, we also identified a previously unknown oceanic stopover area in the North Atlantic used by birds from at least two breeding populations (from Greenland and Iceland). Although birds from the same colony took one of two alternative southbound migration routes following the African or South American coast, all returned on a broadly similar, sigmoidal trajectory, crossing from east to west in the Atlantic in the region of the equatorial Intertropical Convergence Zone. Arctic terns clearly target regions of high marine productivity both as stopover and wintering areas, and exploit prevailing global wind systems to reduce flight costs on long-distance commutes.

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