The adult Lesser Black-backed Gulls in the colony at IJmuiden Forteiland, the Netherlands, are currently incubating their eggs for the 2021 breeding season. For those which have been fitted with a UvA-BitS GPS logger in 2019 or 2020, the downloaded data has revealed where they have spent the previous winter and how they got there and back.
Some of the chicks that were born in 2019 and 2020 also have been fitted with a GPS logger from which the data is sent remotely at regular intervals. Based on the latest data from the beginning of April, they were still in their wintering locations (this is normal because young Lesser Black-backed Gulls don’t start breeding until they are at least 3 years old).
The overviews below (for which Prof dr. Judy Shamoun-Baranes from the University of Amsterdam has kindly given me permission to show them here) show these locations and routes. Click for a larger view. For more information about the project, see the end of this post.
The adults showed a wide variation in wintering locations, ranging from as close to the colony as the United Kingdom and France, to as far south as Morocco and Algeria.
Young from 2019 and 2020
The young that were born in 2019 and 2020 are in their wintering locations in France, Spain, Portugal, and Morocco.
The ones that were born in 2019 could possibly return this year to Forteiland or another colony to inspect a future breeding location, or else do so next year. In 2022 they will be 3 years old (in their 4th calendar year) which is the earliest age at which Lesser Black-backed Gulls breed for the first time.
About the project
The tracking study is part of an ongoing collaboration between the University of Amsterdam UvA (Prof dr. Judy Shamoun-Baranes) and the Royal Netherlands Institute for Sea Research NIOZ (Dr. Kees Camphuysen).
The study is being conducted within the project “Interactions between birds and offshore wind farms: drivers, consequences and tools for mitigation” funded by NWO Applied and Engineering Sciences Open Technology Programme, Rijkswaterstaat and Gemini windpark.
The tracking study will provide complementary information on the movement patterns of gulls breeding along the North Sea coast, with similar objectives to the studies conducted on Texel and Schiermonnikoog.
The main aim is to identify intrinsic and external drivers of movement from fine scale flight behaviour to seasonal migrations. While adult gulls from other colonies have been tracked since 2008, little is still known about the daily movements and flight behaviour of juveniles and how this differs from adults.
This study will contribute to our knowledge on how juvenile birds develop their foraging and migration strategies and how their flight behaviour differs from adults.