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|V 1CY, 2025, colony Lelystad, 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|V and metal NLA 5.641.094, ringed as pullus Larus cachinnans on May 13 2025 at Lelystad, the Netherlands. Ringed by Roland-Jan Buijs ringing team (Mars Muusse / Thijs Horst / Fred Cottaar).
Mother: adult Caspian Gull g-M|1.
Father: adult Caspian Gull.
Nest: 'vuilnisbakkie' (252) g-M|1. In 2025, g-T|V fledged, other 2 chicks died, stuck between rocks. Fledging rate for this nest 2025 = 1,0.

Recoveries:
13-06-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read Thijs Horst
25-06-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read Thijs Horst
29-06-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read T. Horst & M. Muusse
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
11-07-2025 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read Thijs Horst

Visits and data 2025, 'vuilnisbakkie' (252) g-M|1.

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|1 (252) cach cach 73,7 49 73,4 48,6 73 49,8 3
dam:
dam 2 west
location:
Vuilnisbakkie (nest 252), was nest g-A|D in 2024, but g-A|D not seen in 2025
ouders:
new female cachinnans, not g-A|D. Trapped this year, now g-M|1. Male is same as 2024, unringed.
ringed:
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
23-04-2025 g-M|1 5641002 nest Vuilinisbakkie cach F >4CY 454 887 124 54,8 68,4 17,4 6  
13-05-2025 g-T|V 5641094 252 PONT pullus 302
09-06-2025 g-T|V
5641094
 PONT pullus 673 CONTROL
OBSERVATIONS:
01-04-2025 nest
cach breeding, Not g-A|D, but unringed female
12-04 nest
flying adult
21-04 nest
Now several spoonbills surrounding this nest
21-04 adult
2x caspian gulls at nest, 1 is incubating. Attempt to trap a breeding bird, failed.
23-04 eggs 3 eggs
23-04 adult
trapped female, now g-M|1, incubating 3 eggs at nest Vuilnisbakkie
01-05 chicks
2x wet chicks, 1x egg
08-05-2025 adult
both partners present and 1 chick
13-05-2025 chicks
1 chick ringed, 2 chicks dead stuck between rocks.
09-06-2025 chicks
g-T|V found and measured. This chick fledged.

below: Caspian Gull cachinnans T|V 1CY, July 11 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.

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

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

Chick g-T|V & mother g-M|1.

below: Caspian Gull cachinnans T|V 1CY, June 29 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans T|V 1CY, June 25 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans T|V 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
13-05-2025 G-T|V .5641094 252 PONT   pullus   302         Ringed pullus
09-06-2025 G-T|V .5641094   PONT   pullus   673          
14-06-2025 G-T|V dam 2 WATER PONT pullus          

below: Caspian Gull cachinnans T|V 1CY, May 13 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.