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 T|4 1CY, July 13 2025, colony De Kreupel, the Netherlands. Picture: Thijs Horst & Mars Muusse.

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

Tibia G-T|4 and metal NLA 5.641.860, ringed as pullus Larus cachinnans on May 25 2025 at Lelystad, the Netherlands. Ringed by Roland-Jan Buijs ringing team (Mars Muusse / Thijs Horst / Fred Cottaar).
Mother: adult Caspian Gull g-A|M.
Father: adult Caspian Gull r-7L.
Nest: r-7L & g-A|M. In 2025: g-T|4 only fledged chick. Fledging rate for this nest 2025 = 1,0.

Recoveries:
31-05-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read T. Horst & M. Muusse
13-07-2025 IJsselmeer (De Kreupel), Noord-Holland, NL 5.247,00 N 513,00 E colourring read T. Horst, M. Muusse & N. Colpaert
18-07-2025 IJsselmeer (De Kreupel), Noord-Holland, NL 5.247,00 N 513,00 E colourring read T. Horst & M. Muusse

Visits and data 2025 for nest r-7L & g-A|M.

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
r-7L & g-A|M cach cach 70,8 51 70,2 51,4 68,7 51 3
dam:
dam 1 west
location:
cluster 60: nest Urker Flag, at edge tarmac and vegetation, 5 mtr E of nest 60
parents:
moved paired, new nest, was LBBG
ringed:
date darvic metal location / nest# species sex age wing mass head+ bill bill tarsus gonys greyscale
23-04-2025 r-7L 6214904 Nest g-A|M & r-7L cach M >4CY 465 1160 136,7 64,3 76,2 20,4 8 Fred Cottaar
25-05-2025 g-T|4 5641860 r-7L & g-A|M PONT pullus 399
OBSERVATIONS:
21-04-2025 eggs
3x eggs measured,
adult
g-A|M lands at nest,
nest
No longer nest 62-2024, but moved to Flag Urk, at edge vegetation, Only visible from S-side,
23-04 adult
CONTROL: trapped male r-7L, incubating 3 eggs,
28-04 eggs 3 eggs
01-05 eggs 3 eggs
25-05 nest
1 chick ringed, 1 rotten egg, 3rd egg?
31-05 chicks
g-T|4 present, not measured

below: Caspian Gull cachinnans T|4 1CY, July 13 2025, colony De Kreupel, the Netherlands. Picture: Thijs Horst & Mars Muusse.

below: Caspian Gull cachinnans T|4 1CY, May 25 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.

date darvic metal nest species sexe age wing mass head+ bill bill gonys barcode comments
25-5-2025 G-T|4 .5641860 r-7.L & g-A|M PONT   pullus   399         Ringed pullus