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 N|A 4CY, 2025, the Netherlands. Picture: Folko van den Brink, 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-N|A and metal NLA 5.641.010, ringed as breeding adult Larus cachinnans on April 28 2025 at Lelystad, the Netherlands. Ringed by Roland-Jan Buijs ringing team (Mars Muusse / Thijs Horst / Fred Cottaar).

Recoveries:
08-05-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read Thijs Horst
25-05-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read T. Horst & M. Muusse
26-11-2025 Lelystad (Oostvaardersdijk), Flevoland, NL 5.228,00 N 519,00 E colourring read Folko van den Brink

Visits and data 2025 nest g-N|A (092).

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-N|A (092) cach cach 74,6 48,8 70,2 48,8 70,3 47,8 3
dam: dam 1
location:
underneath 'round' tree opposite pumping station, Red jerrycan on boulder at waterfront.
ouders:
new female, trapped art nest and ringed g-N|A.
ringed:
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
28-04-2025 g-N|A 5641010 92 PONT F 4CY 446 876 127,9 55,8 68,8 16,8 5,5
25-05-2025 g-T|2 5641856 92 PONT pullus 114 ringed pullus
25-05-2025 g-T|3 5641857 92 PONT pullus 130 ringed pullus
25-05-2025 5641858 92 ?? ?? pullus 56 ringed pullus
09-06-2025 G-T|2
5641856
 PONT pullus 464 CONTROL
09-06-2025 G-T|3
5641857
 PONT pullus 323 CONTROL
OBSERVATIONS:
25-03-2025 nest
2x cach present, 2024 was 2x 4cy cach.
04-04 nest
2x cach present, Nest is really way underneath the bush.
21-04 nest
1 egg, Not measured, Red jerrycan placed at boulder in front of nest.
25-04 nest 2 eggs.
28-04 adult
3 eggs, adult trapped now g-N|A.
08-05 adult
both partners present.
13-05 nest 3 eggs.
adult
tried to trapped unringed male, but again female caught, and released.
food
vomit bolus is Roach.
25-05 chicks
3x ringed, not sure if 3rd chick belongs to nest.
30-05 chicks
metal ringed chick found dead, metal ring reused.
09-06 chicks
2 chicks found and measured.
30-06-2025 chicks
g-T|2 found dead, ring can be reused.
    Conclusion: g-T|2 found dead & g-T|3 not seen after ringing, 3rd metal only (probably this nest) found dead. Likely failed season.

below: Caspian Gull cachinnans N|A 4CY, November 26 2025, Lelystad, the Netherlands. Picture: Folko van den Brink.

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

below: Caspian Gull cachinnans N|A 4CY, May 08 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.

below: Caspian Gull cachinnans N|A 4CY, April 28 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.

date darvic metal nest species sexe age wing mass head+ bill bill tarsus gonys barcode greyscale comments
28-4-2025 G-N|A .5641010 nest 92 PONT F 4CY 446 876 127,9 55,8 68,8 16,8 25B00550 5,5 Trapped by ringer. Breeder on 3 eggs.