Fly or Float? A glaucous-winged gull story (Part 2 of 2)
September 05, 2012
With our sixteen-foot pontoon boat strategically loaded beyond its brim, I put on my Mustang float coat and survival gear, took a pill to relieve seasickness, and motored out of Seward Harbor bound for the outer reaches of Resurrection Bay. No Name Island, about 25 miles away, was our first stop. Glaucous-winged gulls nest on islands like No Name in the vegetation that clings to exposed ledges. These gulls live in colonies of varying sizes throughout the park. Since colonies are numerous, we're able to compare survey methods (e.g. boat-based versus helicopter-based surveys) across different colonies and environmental conditions covering a large spatial scale. Once we determine a preferred method for surveying the glaucous-winged gull population, we hope to adapt these methods to other cliff-nesting seabirds such as kittiwakes, murres, and cormorants for future studies.
At No Name Island we measured our distance from the cliff and recorded the time, tide, wind, cloud cover, temperature, and visibility - factors affecting our ability to detect birds. Within the colony we counted a subplot of gulls and photographed the birds from various angles. Over the winter Jen will compare observer counts to boat-based photographs and to helicopter-based photographs to determine the accuracy, efficiency, and costs associated with each survey method. These same survey methods were applied to colonies on nearby Chat Island. We repeated alternating surveys at these two sites to document change in colony attendance throughout the day.
That night we traded choppy swells on the outer coast for the stable ground of the Aialik Bay Ranger Station. We ate a much anticipated hot meal on the rocky beach and took in the view of Aialik Glacier calving in the distance. We rested and repeated with similar trips on 10-day stints throughout June and July. Our surveys aim to account for the variation in breeding adult attendance across counts, days, and time of season. As the summer progressed, vegetation and chicks grew up simultaneously around the adults.
While I bundled myself in multiple layers of wool and fleece and worked amid the wind, rain and, at times, sun, I was often amazed at how well cliff nesters like kittiwakes and glaucous-winged gulls thrive in such exposed conditions. Even in hard, driving rain and large, white-capped waves they fly and float as if it's just any other day - and for them I suppose it is. They're one tough group.
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Did You Know?
Snowfall on the Harding Icefield can exceed 100 feet each year. After 4-10 years of compression snow turns into glacial ice.