Diurnal variation in the behaviour of the Pink-footed Goose (Anser brachyrhynchus) during the spring stopover in Trøndelag, Norway

During the spring migration, the Pink-footed Goose Anser brachyrhynchus stops in mid-Norway to refuel before continuing its flight to the Svalbard breeding grounds. While in mid-Norway the geese feed on pasture, stubble and newly sown grain fields. Here, we describe the diurnal variation in goose behaviour at a staging site and assess the extent to which behavioural patterns are attributable to physiological factors (digestibility of the food) and environmental conditions (flock size, type and frequency of disturbance and distance to roost). We found that feeding activity peaked at mid-day, whereas the birds were most alert in the morning and afternoon. The behaviour of Pink-footed Goose also varied with habitat type, disturbance level and distance to roost. The diurnal variation in feeding activity differed from behaviour reported for geese on the wintering grounds, indicating that the birds have different energetic and nutrient demands when at spring staging sites. Seasonal changes in habitat availability as well as density dependence may also affect the birds' behavioural patterns. A sporadic, unpredictable disturbance reduced the proportion of geese feeding to a greater extent than a predictable, recurrent disturbance, but feeding activity was highest under undisturbed conditions.