IJmuiden Lesser Black-backed Gull GPS-project update: juveniles on their way back and adults in the media

In this update on the Lesser Black-backed Gulls from our IJmuiden Forteiland project that are fitted with a GPS logger we can report that some of the juveniles from last year are making their way back to the Netherlands. Also, the behaviour of the adults has made the national media.

See the end of this post for information about this project.

The juveniles

Of the 6 juveniles that have been spending their winter in France, Spain, and Morocco, 5 have moved north, 4 of them quite considerably:

  • YCWF/5946 Is still in France and has moved from the east of Nantes a bit north to the east of Caen.
  • YCWT/5797 Is still in Morocco in the El Jadida – Safi region. It visited the landfill of Agadir, Morocco on May 6. It’s a place I know well after having visited it myself in 2017 and 2019.
  • YCXJ/5952 Is still in southern Spain and has moved from Málaga to the south-east of Seville.
  • YCZP/5943 Has moved from Casablanca, Morocco, to Leeuw, Belgium (close to Oostende near the coast and close to the Dutch border. It is only 175 km away from the colony!)
  • YCZN/5942 Has moved from the north of Málaga, Spain, via Madrid to Le Crotoy, France (south of Boulogne-sur-Mer).
  • YCZT/5953 Has moved from Rabat, Morocco, to Lille, France.

Click the image for a larger view (the photos are of the juveniles in 2019):


The adults

Of the 10 adult Lesser Black-backed Gulls that were fitted with a GPS logger last year, 7 have now returned. After returning from their wintering grounds, they immediately took up their usual trips to urban areas and the North Sea (see the next item about the corona virus).

YBJC with logger 5491 in the colony on 11 May 2020:


Trips inland

Some individuals also make long-ish trips inland.

YASV/5963 has made trips to Den Bosch and to a waste disposal site in Tilburg (both 100 kilometers south-west of IJmuiden).

Below: trip to Den Bosch in April via The Hague and Rotterdam, and back via Utrecht:


Below: trip to Tilburg in May:


YBKW/5861 made a trip to Den Bosch via Rotterdam mid-April:

YBKW 20200415 Den Bosch

Corona virus and the media

At the time of writing (early May 2020), the Covid-19 Corona pandemic has forced the Netherlands in an almost complete lock-down. From March until mid-May, all citizens were asked to stay home as much as possible and to only go out for shopping or a short walk. This has brought the country to an almost complete stand-still, resulting in empty streets, parks, and beaches.

This coincided with the Lesser Black-backed Gulls returning from their wintering grounds in southern Europe and northern Africa back to their breeding colonies in March. As the GPS-tracks from last year already showed, our Lesser Black-backed Gulls from IJmuiden regularly visit urban areas for food.

How has the Corona crisis affect their foraging behaviour?

The GPS tracks from this year show that the Lesser Black-backed Gulls from IJmuiden have not (yet) changed their foraging locations and are still visiting the same spots in Amsterdam and Hoofddorp (where people are still feeding them), while still also making regular trips out to the North Sea.

The following image shows the tracks from 3 April 2020 of 5 different individuals visiting their regular locations. (Click for a larger view.)


The Dutch media showed interest in how nature responds to the effect of having less people outside and wanted to know ‘where the gulls were getting their fries from’ and whether or not there are less gulls in the cities.

On 24 April an article appeared in the newspaper de Volkskrant and on 2 May the NOS made a tv-item for which they interviewed project leader Judy Shamoun-Baranes (the item starts at 10:10 minutes) and posted an article on their web site.

Judy Shamoun-Baranes later tweeted the following:

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.

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