Report from Fågelsundet
It's early May on Sweden's east coast, just to the south of Gävle, where we will be GPS tracking a range of the larger gull species (herring, lesser black-backed, and greater black-backed) and the magnificent Caspian tern.
We are using solar-powered GPS trackers (see: http://www.uva-bits.nl/) which have a wi-fi like wireless connection to a base-station antenna. This system allows us follow both the foraging flights and migratory movements of the species in great detail.
We caught our male greater black-backed gull using a 'spring-trap', set at its nest. When he returned to incubate the eggs at the nest he was caught.
We then deployed a GPS tracker and took various measurements. In part these will be used to compare flight between gulls with different wing areas and aspect ratios (ratio of wing-span to wing-cord).
As we release him, we wonder, what story will we learn from his GPS tag?
written by Helena Osvath kl. 01:32