Individual adaptation to a dynamic environment in geese

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The purpose of the experiment is to study the effect of climate change (phenology of migration and breeding), goose numbers (intraspecific competition, density), diseases and pollution on a flock of arctic breeding barnacle geese. Individual reproductive success depends on age, pairbond, dominance and timing and varies between years and social classes. We want to understand the best individual strategies to cope with a fast changing environment. This project will put one individually coded coloured plastic leg rings on barnacle geese to identify individuals during field encounters. The birds will also be equipped with the standard metal migration ring of Stavanger Museum as a permanent marking on the other leg. When the birds are free ranging, observations on status (pair bond, reproductive success, clutch size, survival of young), behavior (dominance, food intake, condition) and location (timing, terrain use and migration) are monitored to build complete life histories. These life histories are combined with data collected during the catch on size, growth, body condition and health parameters from blood sampling.

Catching of wild birds will cause some distress, but has no clear effects after release. The ringing and blood sampling is generally mild, the leg rings have no observed negative effects even when a geolocator is attached to the ring.

The benefit of the research is mainly scientific as the long detailed time series spans several generations and a whole ecosystem. There is also relevance for population management, especially now climate change is accelerating and population reduction by hunting might be introduced in this species as a management tool.

Annually, the experiment will catch 250 barnacle geese, of which 125 will receive a new colour ring, all will be measured, 100 individuals will be sampled for blood and tracheal swaps. Priority will be on goslings.

The whole study is based on a long data series which has been optimized in the past for animal numbers and methodology. The fast changes in the environment, the high variability in reproductive output and the potential change in management make a relative constant effort in this population important to document population parameters and adaptation.