IJmuiden Lesser Black-backed Gulls fitted with GPS-loggers – update November 2019

An update on the 9 first-calendar year Lesser Black-backed Gulls of our IJmuiden Forteiland project that have been fitted with a GPS logger in 2019. The main news is that one of them is now in Morocco!

The information is based on data up to November 9, 2019.

For information about the project, see the end of this post.

Request: images of these locations or of course these gulls are very welcome!


The following list shows the ring code, logger code, and latest location:

  • YCWF 5946 France
  • YCWT 5797 Spain
  • YCWU 5951 Spain
  • YCXJ 5952 United Kingdom
  • YCZN 5942 Spain (new location)
  • YCZP 5943 Spain (new location)
  • YCZR 5944 The Netherlands
  • YCZS 5950 Died in the Netherlands, September 2019.
  • YCZT 5953 Morocco (new location)


We’re excited to see that YCZT/5953 has reached Morocco and is now at Rabat! It got there via northern France and the coast of Spain and Portugal.

YCZT on a beach near the IJmuiden gull colony when I saw it in August 2019:

United Kingdom

The last known position of YCXJ/5952 is still near Newbury. However, this dates back from mid-October so it may have moved since then.


YCWF/5946 is still in Northern France, roughly in the Calais, Boulogne-sur-Mer, Saint-Omer triangle.


YCZP/5943 and YCZN/5942 have joined YCWT/5797 and YCWU/5951 in Spain.

YCZN moved from the UK to the south of Madrid.

YCZP/5943 moved from France to Andalusia, Spain via Zaragoza and Malaga.

YCWT/5797 is still in south-west Spain and is currently just south of Seville.

YCWU/5951 is still on the east coast of Spain at Deltebre, just south of Barcelona.

The Netherlands

YCZR/5944 was still in and around Amsterdam at the end of October.

About the project

(Source: http://www.uva-bits.nl/project/daily-movements-of-gulls-from-forteiland-ijmuiden/)

The tracking study is part of an ongoing collaboration between the University of Amsterdam UvA (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.


If you come across any of our gulls from the IJmuiden Forteiland project, please let us know.

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