Annual movement patterns of endangered ivory gulls: the importance of sea ice.

Nora C Spencer,H Grant Gilchrist,Mark L Mallory,Hans-Ulrich Peter

doi:10.1371/journal.pone.0115231

Nora C Spencer, H Grant Gilchrist + Show 2 more

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https://doi.org/10.1371/journal.pone.0115231

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Abstract

The ivory gull (Pagophila eburnea) is an endangered seabird that spends its entire year in the Arctic environment. In the past three decades, threats from various sources have contributed to a >70% decline in Canada. To assess the annual habitat needs of this species, we attached satellite transmitters to 12 ivory gulls on Seymour Island, Nunavut in 2010, which provided up to four breeding seasons of tracking data. Analysis of migratory behaviour revealed considerable individual variation of post-breeding migratory route selection. Ivory gulls traveled a median of 74 days during post-breeding migration, but only 18 days during pre-breeding migration. In contrast to predictions, ivory gulls did not use the Greenland coast during migratory periods. Ivory gulls overwintered near the ice edge in Davis Strait, but also used the Labrador Sea in late February and March. We suggest that the timing of formation and recession and extent of sea ice plays a large role in ivory gull distribution and migratory timing.

Highlights

The Arctic marine environment is changing in response to from a variety of anthropogenic activities [1]
We suggest that the timing of formation and recession and extent of sea ice plays a large role in ivory gull distribution and migratory timing
Ivory gulls breeding at the Seymour Island colony used areas north of Parry Channel to forage during late migration (pre-breeding, during breeding, and principally north and south of Parry Channel post-breeding (Fig. 1)

Summary

Introduction

The Arctic marine environment is changing in response to from a variety of anthropogenic activities [1]. Climate trends and models show global temperatures increasing with anticipated reductions in sea ice cover, which may be accelerating interest in resource exploitation in the Arctic [2, 3]. Warming air temperatures and thinning sea ice mean that annual ice is replacing marine habitats that traditionally are covered in multi-year ice [4, 5]. In 1987, 57% of sea ice in the Arctic basin was $5 years old; in 2007 that number had dropped to 7% [6]. The Arctic is changing more rapidly in response to global warming than any other area of the world; continued assessment and monitoring of this sensitive environment and how warming trends are influencing.

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