Larus cachinnans in the Netherlands
(last update: August 16, 2020)
Albert de Jong
Merijn Loeve
Roland-Jan Buijs
Thijs Horst
Leon Kelder
Mars Muusse
Caspian Gull cachinnans 6.V 1CY-4CY, May 2022 - April 2025, the Netherlands & England. Picture: Rob Creek, Thijs Horst & Mars Muusse.
Red tibia ring r[6.V] and metal NLA 5.625.173, ringed as pullus Larus cachinnans hybrid at nest X540 on May 30 2022 in colony Lelystad, the Netherlands. Ringer: Albert de Jong - Roland-Jan Buijs ringing team.
ID certain in 2022: one parent is adult cachinnans, other parent is German 5CY y[X540] which may have a bit of argentatus blood.
Recoveries:
18-10-2022 Manchester (vuiloverslag), Greater-Manchester, ENGELAND 5.327,00 N 212,00 W colourring read Rob Creek
30-07-2023 Neder-over-Heembeek (Vuiloverslag), Brussel, BELGIE 5.053,00 N 422,00 E colourring read Maurice Segers & Michel Janssens
17-09-2023 Neder-over-Heembeek (Vuiloverslag), Brussel, BELGIE 5.053,00 N 422,00 E colourring read Maurice Segers
12-04-2024 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read M. Loeve & M. Muusse
17-04-2024 Almere (De Vaart), Flevoland, NL 5.224,00 N 514,00 E colourring read Thijs Horst
02-05-2024 Alkmaar (Vuiloverslag), Noord-Holland, NL 5.236,00 N 445,00 E colourring read Maarten Hotting
31-05-2024 Lelystad (Bataviahaven), Flevoland, NL 5.230,00 N 525,00 E colourring read Merijn Loeve
27-07-2024 Almere (De Vaart), Flevoland, NL 5.224,00 N 514,00 E colourring read Eric Roeland
02-09-2024 Oostknollendam (De Merken), Noord-Holland, NL 5.230,00 N 449,00 E colourring read Kees Floris
10-04-2025 Almere (De Vaart), Flevoland, NL 5.224,00 N 514,00 E colourring read Thijs Horst
13-06-2025 Markermeer (Marker Wadden), Flevoland, NL 5.235,00 N 522,00 E colourring read Thijs Horst
21-07-2025 Almere (De Vaart), Flevoland, NL 5.224,00 N 514,00 E colourring read Thijs Horst
Data for nest X540-2022
| 19-04-2022 | behind nest 17, landing Caspian Gull and Caspian (hybrid?) y-X540. Best viewed from north side. | ||||||
| 29-04-2022 | 3 eggs | egg no: | width (mm) | length (mm) | volume (cm3): | water test on April 29th: | |
| A egg | 49,8 | 72,5 | -- | 50 - tip on bottom | |||
| B egg | 48,3 | 71,4 | -- | 90 - tip on bottom | |||
| C egg | 48,8 | 71,6 | -- | 65 - tip on bottom | |||
| 04-05-2022 | 2 adults at nest, including y-X540. | ||||||
| 09-05-2022 | 3 eggs. | ||||||
| 17-05-2022 | 2 eggs and 1 chick. B egg and C egg are hatching. | ||||||
| pullus ringed with metal NLA .5625133 | |||||||
| 30-05-2022 | 2 chicks | metal | darvic | Mass | Wing | Head+Bill | Bill |
| .5625172 | r-6U | 421 | 70 | 79,1 | 33,7 | ||
| .5625173 | r-6V | 410 | 84 | 78,5 | 28,2 | ||
| 3rd chick is dead in the nest. | |||||||
| 02-06-2022 | adult y-X540 present and aggressive. | ||||||
| 17-06-2022 | 3 ringed chicks are standing in nest 17, club of nest 17 together with nets 223 most likely. | ||||||
| 21-06-2022 | both parents present. | ||||||
| 28-06-2022 | adult y-X540 present. | ||||||
| 12-07-2022 | adult male present with chick r-6.U. | ||||||
| 17-07-2022 | adult male present with both chicks r-6.U & r-6.V. | ||||||
below: Caspian Gull cachinnans 6.V 4CY, April 10 2025, Almere - De Vaart, the Netherlands. Picture: Thijs Horst.
Offspring of y-X540 (hybrid-type), which lacks a mirror on P9 in 4CY.
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below: Caspian Gull cachinnans 6.V 3CY, September 02 2024, Oostknollendam, the Netherlands. Picture: Kees Floris.
below: Caspian Gull cachinnans 6.V 3CY, April 12 2024, colony Lelystad, the Netherlands. Picture: Merijn loeve & Mars Muusse.
below: Caspian Gull cachinnans 6.V 1CY, October 18 2022, Manchester, England. Picture: Rob Creek.
below: Caspian Gull cachinnans 6.V 1CY, July 17 2022, Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.
below: Caspian Gull cachinnans 6.V 1CY, May 30 2022, Lelystad, the Netherlands. Picture: Mars Muusse.
r[6.V] cachinnans from nest 223 y[X540]. Picture: May 30th, 2022.
Ringed on May 30th. Last positive ring reading from that date. Same for sibling r[6.U].
However, June 17th, several ringed chicks present in neighbor nest 17, likely including chicks from nest 223.
