Guillemots and razorbills are among the seabirds considered most vulnerable to displacement by offshore wind farms. Due to the challenge of tracking seabirds for a prolonged period of time, there is a knowledge gap when it comes to following their movements during non-breeding seasons and assessing the impact of offshore wind developments on these movements.
This project aims to provide detailed and accurate data on the year round movements of adult birds by using geolocator tags to collect movement data over several years which commenced in 2017. The tags are small enough to be fitted to a leg ring and have a battery life of up to five years. They can record light intensity and sea surface temperature (SST) on a time base memory chip. The combination of both measurements allows for a refined position estimate for guillemots and razorbills, particularly because SST varies considerably in different locations.
Both species have long lifespans and adults come back to the same nest site year after year. A number of ringing groups regularly visit accessible colonies and this project makes use of their knowledge and expertise to support in attaching tags to birds’ legs which can then be collected in subsequent years to recover and analyse. Data is being collected from a number of colonies within the north of the UK ranging from the Hebridean island Canna to the Farne Islands in Northumberland.
Ultimately, this project should inform any displacement concerns and allow for less uncertainty in impact assessment for these species which will be key to planning for future developments.
Professor Bob Furness, Principal Ornithologist at MacArthur Green, said: “It is very exciting to be able to deploy tags on guillemots and razorbills to learn about their migration routes and wintering areas. Until now, our knowledge of their migrations has mainly come from recoveries of ringed birds found dead on beaches in winter, which can give a very biased picture. This project will allow us to track the routes used by birds, and which areas they spend time in throughout the winter.
“We are particularly interested to find out if these migrations differ between birds from different colonies, and whether individuals use different areas from year to year or consistently go back to favourite locations. That knowledge will not only help in assessment of the impacts of offshore wind farms but will also help us understand how best to conserve these internationally important seabird populations that are an iconic part of Scotland’s wildlife heritage.”