Forsøksdyr: Use of glacier fronts as a way to compensate for a warming sea: a multi-colony and multi-species analysis

Godkjenningsdato 19.04.2018

Recent studies in several Arctic regions, including Svalbard, stress the importance of tidewater glaciers as key foraging areas for seabirds. It has been suggested that glacier melting and the increase in glacier discharge may counterbalance, at least over the short-term, the negative consequences of sea-ice loss by increasing coastal productivity. However, the fundamental understanding of this phenomenon, the relative importance of glacier fronts as foraging areas for seabirds and the spatial and temporal variation in use of these areas are unknown. Continued warming is expected to reduce the number of tidewater glaciers and also the overall length of calving fronts. How this will affect seabird foraging and then seabird populations remains unknown. Here, we propose to continue and develop a project that started in 2016 and that combines individual monitoring of Svalbard seabirds combined with demographic monitoring (i) to determine the importance of glacier front as key foraging hotspots in Svalbard and (ii) to assess whether or not different use of glacier fronts during the breeding season are associated with different breeding success and population trends.

The project will focus on black-legged kittiwakes and Brünnich’s guillemots. Each summer, 40 kittiwakes in 5 colonies on Svalbard and 20-30 Brünnich's guillemot in 1 colony will be fitted once with GPS logger (11g) during the breeding season. Loggers will stay only 2-4 days on the bird and such method has very minimal detrimental effects on the birds. Such loggers are widely used on seabirds and predicted harm will only be a small discomfort and potentially a slight increase in the foraging energetic effort. This will not lead to any long-term effect and will not affect bird reproduction or survival.
Compliance with the 3Rs:
Black legged kittiwakes and Brünnich's guillemots are the main focus of the project, and the study of their relationship with their environment require the use of animals from wild populations that can move and behave freely. Therefore, no other species or model can be used to answer our questions.
It is likely that 10-30% of the loggers will either not work properly and/or fall off the bird before recapture. We are dealing with cutting edge technology and miniaturization and there is always a probability that the logger will not work properly. Therefore, our sample sizes represent minimum samples to get a representative description of the foraging areas used by those birds in the different colonies.
We will be using some of the smallest loggers available on the market. Those GPS loggers weigh only 11 g (<4% of kittiwake body mass and <2% of guillemot body mass). This will ensure that bird behaviour is not significantly affected and minimize discomfort while maximizing data quality/relevancy.