Forsøksdyr: Timing of wing moult in barnacle geese related to environmental changes

Godkjenningsdato 07.04.2020

Godkjenningsperiode 14.07.2020-13.07.2022

1 Purpose
The project is part of a long-term study on population dynamics in barnacle geese breeding in Svalbard. A main aspect of the study concerns monitoring of survival and reproduction rates for scientific and applied reasons. Can we understand and predict processes in the population that are related to environmental change (such as by climate warming)? The work is based on animals that can be identified individually and whose activities are recorded at consecutive steps in the annual cycle. Currently we focus on two main issues. (1) Barnacle geese exhibit a striking shift in distribution while staging along the Norwegian coast during spring migration. Given potential economic consequences (crop damage), knowledge on this development is urgently needed. (2) Throughout the Arctic, including Svalbard, the hydrology of tundra lakes runs an increasing risk of collapse by elevated evaporation and permafrost degradation. During wing moult, barnacle geese depend on these lakes for food and safety. How flexible are the geese in timing of wing moult such that moulting is completed before the lakes have dried up? We hypothesize that geese are only able to advance the onset of moult by shifting forward the timing of migration and egg-laying.

2 Distress
To identify the geese, we use plastic rings with letter codes that can be read at distances of hundreds of meters. The rings are small for the size of a goose (3 cm tall and weighing 3 g, or 0.2% of the average body weight). This type of rings is used since the onset of the study in the 1970s, and adverse effects on the birds' performance have never been suspected.
3 Expected benefit
By better understanding in which way important events in the annual cycle are constrained, population models can be improved. Predictions of population size is important to estimate positive and negative effects of climate change. These results provide the tools for management actions for protecting the geese or predicting crop damage.
4 Number of animals, and what kind
We aim to catch 627 individuals of barnacle goose Branta leucopsis, of which 330 to mark..

5 How to adhere to 3R
The barnacle goose is the target of field study per se, which precludes replacement. We reduce the number of birds marked to such an extent that we will have a sufficient number of birds with observation records during migration, egg-laying and moult. We improve the method of catching by making the catching corral from cotton rather than from nets. To reduce the number of catching events we only mark once every five years.