Colour ringing reseach in the context of the Black-headed Gull in the context of RAS is being pursued in Harderwijk and Zoetermeer.
In addition to this as on a yearly basis some Mediterranean Gulls are being (colour)ringed from by-catch.

See here for a unique list of all ring recoveries from by me, in the breeding season ringed Black-headed gulls. See each month on the map.


On the Veluwemeer near Harderwijk I have started ringing approx. 500 young Back-headed Gulls every year since 1998. As only a metal ring was being used the numbers of resightings was low.
Therefore, in 2005 in the context of RAS a start was made of colour ringing of approx. 100 young every year. This provides more foreign resightings, as opposed to all the resightings from all the preceeding years taken together. In addition to this, since 2006 approx. 25 adult breeding birds are caught on the nest and colour ringed on a yearly basis.

Ringing site Harderwijk, Veluwemeer (green marker) and foreign readings:
During the breeding season (red marker) and outside the breeding season (blue marker),

Google Maps: markers are clickable, zooming in and -out, and sliding is possible.

In the context of this RAS research, in 2006 a start was made with reading (colour) rings on a small dyke adjacent to the colony. During the seasons 2006-2009 this has resulted in almost 5,500 observations on almost 950 individuals.

Reading site on the dyke near the colony. April 2008

Number of ringed Black-headed Gulls, young and adult breeding birds Veluwemeer, Harderwijk:
Year Metal ring Colour ring Adults returned from earlier years
1998 392 0 0
1999 400 0 0
2000 521 0 2
2001 514 0 2
2002 505 0 2
2003 446 0 19
2004 322 0 4
2005 19 92 19
2006 289 122 177
2007 72 126 331
2008 53 116 360
2009 65 135 356
2010 105 209 380
2011 23 109 272
Total ringed 3726 988  

The colour ringing of a not yet fully mature Black-headed Gull (white E3CS). Jun 3rd 2008.
Codes used:
White, starting with the letter E, followed by 1 number and 2 letters:

Nestling Black-headed Gull with egg. May 7th 2008.

Video images:

There are more photo's of the ringing of breeding birds (adult birds and young) to be seen (Photo & video Benny Middendorp):
Gallery May 7th 2008
Gallery Jun 6th 2008

White E1SS (born in colony Harderwijk) in Spain. November 2009.


In 2009 a similar RAS research project was started at the Benthuizerplas, near Zoetermeer in The Netherlands (52,04,32 N - 4,31,58 E). Here, at the beginning of June 2009 in total 56 adult breeding birds were given a white colour ring and approx. the same number of Black-headed Gulls have all obtained a metal ring.
More information about the ringing research in 2009 and reading rings near Zoetermeer you can find in an article from artikel van Benny Middendorp (Dutch).

Kokmeeuwen kolonie Benthuizerplas, Zoetermeer, 2010. Benny Middendorp

Ringing site Zoetermeer, Benthuizerplas (green marker) and observations outside the colony:
During the breeding season (red marker) and outside the breeding season (blue marker)

Google Maps: markers are clickable, zooming in and -out, and sliding is possible.

Black-Headed Gulls breeding birds ringing for the RAS-project in 2013
In 2013 on 16th June pullus are colour ringed, in the Black-headed gulll colony Benthuizerplas near city Zoetermeer (The Netherlands).

RAS-project in 2012
RAS project in 2010

On June 2nd under supervision of Frank Majoor, Black-Headed Gulls have been ringed in the colony Benthuizerplas at Zoetermeer. In total 122 full grown Black-Headed Gulls were caught and 11 non-fledged young. Some of the full grown gulls were ringed already. In total 118 new metal rings were given (one is re-ringed), of which 55 were also given a white colour ring from the E5-series. For these full grown birds the age composition is as follows: 5 in the 2nd calender year, 5 after second calender year, 2 in the 3rd calender year and 106 in the after 3rd calender year. In total 111 non-fledgled young were caught and given a metal ring, of these 87 were given a white colour ring from the E5 series. Of all birds the biometric data were collected, such as wing length, head length, beak height and weight. In addition influenza samples were taken.

Below several photo's from the ringing on June 2nd 2010.

Ringing Black-headed gulls near kolonie Benthuizerplas, Zoetermeer in 2010. Maarten van Kleinwee & Benny Middendorp

Year Metal ring Colour ring Adults returned from earlier years (update 23-07-2010)
2009 61 56 0
2010 86 142 80
2011 41 83 153
2012 66 73 149
2013 88 69 144
Total ringed 342 423  

Black-headed gull colony Benthuizerplas, Zoetermeer, 2009.

Black-headed gull reading site colony Benthuizerplas (not far from Noordhovense plas), Zoetermeer, 2009.
Photo's Benny Middendorp

White E5AP near colony Benthuizerplas, Zoetermeer. Benny Middendorp

Wit E5RF beach Le Portel, Normandie, Frankrijk - juli 2010. Maarten van Kleinwee.

White E5EJ on beach Omaha, Normandie, France - september 2010. Emmanuel Chabot.

Wit E5CP near Trouville-Sur-Mer, Normandie, Frankrijk - september 2010. Tony Le Huu Nghia

© Frank Majoor. Website update 12-02-2014.