| Summary: | During spring migration, Pink-footed Geese Anser brachyrhynchus stop in mid Norway to refuel before their onward flight to the Svalbard breeding grounds. In mid Norway, geese feed on pastures, stubble as well as newly sown grain fields. The aim of the paper is to describe diurnal variations in the behaviour of geese and to examine whether these variations are driven by digestibility of food geese feed on or also by external factors such as distance to the roost, disturbance and flock size. Based on diurnal flock scans of activity budgets (observations carried out between 05h00 and 22h00 hrs) in each habitat type, we fitted a model containing all predictors we believe may influence geese behaviour. The number of feeding and alert geese on fields displayed a strong diurnal trend, which varied among habitat types, frequent and sporadic disturbance, but not flock size. On roost sites, geese also showed diurnal variation in resting and alertness. The observed diurnal variation differed from what has been found on the wintering grounds indicating that during spring, birds increase their foraging intensity in order to meet energetic and nutritional demands in a short time. Seasonal availability of habitats as well as density dependence due to a rapidly growing population size may also shape diurnal variations in goose behaviour. This study, in combination with diurnal variation in habitat choice derived from a combination of flock scanning and detailed GPS satellite telemetry, may give an input for establishing detailed energy budgets for geese at studied stopover sites.
|
|---|