Forsøksdyr: Individual adaptation to a dynamic environment

Godkjenningsdato 13.06.2018

The purpose of the experiment is to study individual behaviour and reproductive success in relation to annual variation in food availability and predation and the effect of climate change in migratory bird species. Birds receive unique engraved plastic leg rings which can be read from a distance with a telescope without interfering with normal behaviour. We study phenology of migration and breeding, annual variation in reproductive success, intra-specific competition, density, body condition and health status. We want to understand population dynamics and the optimal strategies to cope with a fast changing environment and relate individual behaviour to breeding succes, density and survival using . 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. A subsample of the birds will get geolocators and a few even GPS loggers which on retrieval provide more detailed information on the spatial use and migration timing.

Catching of wild birds will cause some distress. The ringing and blood sampling is generally mild stress. Engraved plastic leg rings, geolocators and GPS-loggers (only for geese) have been tested and used without clear negative effects.

The research tries to understand population processes, constraints and adaptation in a fast changing environment. As the fate of individuals determines all population processes, individual based studies are essential to give insights which can be used for integrated population modelling.
Goose populations keep increasing and management is considered along the flyway. Arctic terns are of concern due to decreasing population numbers and food availability and predation vary annually in both species.

Each year, we will try to catch birds to ring and measure body condition and health status.
Totals over two years:
Barnacle geese 600 caught, 300 newly ringed with engraved plastic rings, 200 sampled for blood, 20 geolocators attached and retrieved, 10 GPS loggers as backpacks.
Arctic terns 120 caught, 80 newly ringed with engraved plastic rings, 20 geolocators attached and retrieved.

The whole study is based on a long data series which has been optimised 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. New techniques with only slightly more distress are applied in small numbers.