IJmuiden Lesser Black-backed Gull GPS-project update – 20200814

In my last update on our GPS-project of the IJmuiden Forteiland colony back in May, I reported on the adult Lesser Black-backed Gulls that were fitted with a GPS logger. Much has happened since then so it is more than time to give another update. This includes:

  • Juveniles of 2020 season also fitted with a logger
  • Loggers recovered from gulls that didn’t make it
  • Where are the 2019 juveniles?

The juveniles of the 2020 season

In addition to the 9 juveniles that were fitted with a GPS logger last year, 9 more loggers were fitted on juvenile Lesser Black-backed Gulls this year. Due to the corona endemic, bad weather, and having to align the schedules of multiple people, this was quite a challenge.

As the juveniles are an important part of the GPS project, we’re very happy to have succeeded in this.

The codes are as follows (colour ring code/logger code):

  • YDDD/7009
  • YDDF/7010
  • YDDN/7011
  • YDCN/7012
  • YDCW/7015
  • YDFD/7017
  • YDFU/7018
  • YDFA/7019
  • YDFV/7020

At the time of writing, all juveniles are still hanging around in the colony where they are being fed by their parents, but they are also starting to explore the surrounding areas (click for a larger view, source: http://www.uva-bits.nl/project/daily-movements-of-gulls-from-forteiland-ijmuiden/).


The loggers of the juveniles will regularly send updates even when they are out of range of the antennas, so we will be able to follow them wherever they go.

Retrieved loggers

Unfortunately, some of the gulls of our GPS-project are no longer with us. Of some of these though, the logger has been retrieved.

Adult YASV/logger 5369

One of my favorite gulls was unfortunately found sick at the end of June and brought into a bird care center where she wasn’t able to recover.

She didn’t breed this year, but kept us entertained by making long and elaborate trips as the following overview shows (click for a larger view, the colony is in the top left corner).


One of my all-time favorite Lesser Black-backed Gull photos of the IJmuiden Forteiland project is of YASV, taken in May 2019:


Adult YBJC/logger 5419

Another one of our favorite gulls also passed away: YBJC. He was famous for very regularly visiting the Erasmusgracht in Amsterdam where he was frequently observed by admirers.

It was brought into a bird care center in Amsterdam in July in an extremely weak state. Although it took in lots of food, it died a few days later. He will be sorely missed.

A typical trip of YBJC from the IJmuiden Forteiland colony to Amsterdam looked like this:


One of the last photos I took of YBJC at the end of June 2020:


Adult YBBJ/logger 5584

We found this gull ourselves in the eastern part of the colony at the end of May 2020.

We had been waiting since the beginning of March for a signal from the logger to indicate that it had returned. It must have returned and died before the antennas were set up.

The logger has been handed over to the University of Amsterdam so that the data can be retrieved from it.


Juvenile YCZT/5953

After being born last year, YCZT travelled via France, Spain, and Portugal to Morocco. Earlier this year it took the same route back but died in a field in France. The location was given to a group of local birders who were able to find the logger. This resulted in a full year of valuable data, as project leader Judy tweeted:

The 2019 juveniles

The juveniles that were fitted with a GPS logger in 2019 are now in their second calendar year. They won’t start breeding until their fourth year at the earliest so until then they will freely roam about. So were are they now?

The ones that are still alive are in the following locations:

  • YCZP/5943 and YCZT/5953 are in northern France, east of Douai.
  • YCZN/5942 Is in the United Kingdom, around Thetford.
  • YCWT/5797 and YCXJ/5952 are in Spain, south of Seville.
  • YCWF/5946 Is in France, to the  east of Caen.

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. Feel free to include me on the e-mail: gulls at vankleinwee.com.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.