Larus cachinnans in the Netherlands

(last update: August 16, 2020)

Coordinators:
Albert de Jong
Leon Kelder
Roland-Jan Buijs
Thijs Horst
Merijn Loeve
Mars Muusse

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Caspian Gull cachinnans R|4 1CY, 2025, Almere & Lelystad, the Netherlands. Picture: Thijs Horst.

You can participate in this project too! Please send in your observations of colour ringed birds to: ring@buijsecoconsult.nl

Tibia G-R|4 and metal NLA 5.641.930, ringed as pullus Larus cachinnans on June 09 2025 at Lelystad, the Netherlands. Ringed by Roland-Jan Buijs ringing team (Mars Muusse / Thijs Horst / Fred Cottaar).
Mother: adult Caspian Gull g-M|4.
Father: adult Caspian Gull.
Nest: Blue Rope (227) g-M|4. In 2025, G-R|4 fledged, while g-T|T & g-T|U not seen after ringing. Fledging rate for this nest 2025 = 1,0.

Recoveries:
30-06-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read Thijs Horst
09-07-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read T. Horst & M. Muusse
04-08-2025 Almere (De Vaart), Flevoland, NL 5.224,00 N 514,00 E colourring read Thijs Horst
20-08-2025 Almere (Dashorstdijk), Flevoland, NL 5.225,00 N 512,00 E colourring read Thijs Horst
24-08-2025 Almere (Dashorstdijk), Flevoland, NL 5.225,00 N 512,00 E colourring read Thijs Horst
06-09-2025 Lelystad (Oostvaardersdijk), Flevoland, NL 5.228,00 N 519,00 E colourring read Folko van den Brink
17-09-2025 Almere (De Blocq van Kuffeler), Flevoland, NL 5.225,00 N 513,00 E colourring read Thijs Horst
16-10-2025 Almere (De Vaart), Flevoland, NL 5.224,00 N 514,00 E colourring read Thijs Horst

Visits and data 2025, Blue Rope (227) g-M|4.

2025 parent 1 parent 2 A_length A_width A_volume B_length B_width B_volume C_length C_width C_volume
TOTAL NEST:
 # eggs
g-M|4 (227) cach cach 71 52 70,9 50,6 66,4 49,5 3
dam:
dam 2 west
location:
nest Blue Rope (227), 12 mtr E of Vuilnisbakkie, dam 2
parents:
same as 2024?
ringed:
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
25-04-2025 g-M|4 5641005 227/blauwe touw PONT F >4CY 455 935 122,5 52,4 68,3 18,3
13-05-2025 g-T|T 5641091 227 PONT pullus 105
13-05-2025 g-T|U 5641091 227 PONT pullus 81
09-06-2025 G-R|4 5641930 227/blauwe touw PONT pullus 664
OBSERVATIONS:
23-04-2025 eggs
3 eggs, measured.
nest
Blue rope flat, between boulders, harder to see.
25-04 nest
g-M|4 female cach trapped on nest, incubating 3 eggs. Now g-M|4.
01-05 chicks
2x wet chick, 1x egg
adult
2x Caspian present
08-05 adult
both partners present
13-05 chicks
2 chicks ringed, 1 egg hatching
09-06 chicks
1 chick found and ringed. Eventually: g-R|4 fledged, while g-T|T & g-T|U not seen after ringing.

below: Caspian Gull cachinnans R|4 1CY, October 16 2025, Almere, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans R|4 1CY, August 20 2025, Oostvaardersdijk - Almere, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans R|4 1CY, August 04 2025, Almere - De Vaart, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans R|4 1CY, July 09 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans R|4 1CY, June 30 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans R|4 1CY, June 09 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.

date darvic metal nest species sexe age wing mass head+ bill bill gonys barcode comments
9-6-2025 G-R|4 .5641930 227/blauwe touw PONT   pullus   664         Ringed pullus