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 hybrid XCHP 1CY-8CY, 2018-2025, Lelystad & Almere, the Netherlands. Picture: Pascal Lepretre, Thijs Horst & Mars Muusse.
DEH EA-211894 and y-XCHP, ringed as pullus Caspian Gull (Larus cachinnans) on June 06 2018 in a mixed Caspian Gull colony at Gräbendorfer See - Lausitz, Brandenburg, Germany (51°42'00"N 14°06'00"E).
In 2022 breeding bird at colony Lelystad, the Netherlands with male cachinnans in nest XCHP.
Visits and data for this nest 2022:
| 11-04-2022 | XCHP present, low on blocks. | ||||||||||||||
| 12-04-2022 | XCHP & partner present. | ||||||||||||||
| 15-04-2022 | XCHP & partner present. | ||||||||||||||
| length | width | water test | |||||||||||||
| 29-04-2022 | 2 eggs | A egg | 68,1 | 49,9 | float - 2 mm | XCHP & sub-adult partner. 2 eggs clutch. | |||||||||
| B egg | 68,6 | 51,1 | float - 1 mm | XCHP is hybrid type (no mirror P9) en 4CY is subad cach type. | |||||||||||
| 09-05-2022 | XCHP present. No chicks found. | ||||||||||||||
| 17-05-2022 | metal: | darvic: | mass: | Head + Bill | Bill | ||||||||||
| pullus | .5625128 | r-51 | 285 | 74,4 | -- | ||||||||||
| pullus | .5625129 | r-50 | 351 | 77,4 | -- | ||||||||||
| 22-05-2022 | No chicks found. | ||||||||||||||
| 30-05-2022 | metal: | darvic: | mass: | Head + Bill | Bill | ||||||||||
| pullus | .5625128 | r-51 | 764 | 99,5 | 36,6 | ||||||||||
| pullus | .5625129 | r-50 | 861 | 104,7 | 41 | ||||||||||
| 02-06-2022 | y-XCHP & partner present. | ||||||||||||||
| 21-06-2022 | y-XCHP & partner present. | ||||||||||||||
| r50 & r51 swimming and flying south of dam 2. | |||||||||||||||
| 28-06-2022 | y-XCHP & partner present. | ||||||||||||||
| r50 & r51 swimming and flying south of dam 2. | |||||||||||||||
| 17-07-2022 | photographed y-XCHP | ||||||||||||||
Visits & data for XCHP-2023:
| egg sizes & volume 2023 | ||||||||||||
| SPECIES | NEST | A_length | A_width | A_volume | B_length | B_width | B_volume | C_length | C_width | C_volume | TOTAL NEST: | known parents? |
| cach x cach | XCHP | 70,6 | 52,2 | 96,86 | 67 | 52,7 | 93,69 | 68,3 | 50,8 | 88,75 | 279,30 | same as 2022 |
| ring pulli: 12-mei | laying A egg: 7-apr | hatch A egg: 5-mei | ||||||||||
| catch: | date: | metal: | darvic: | mass: | wing: | head+bill: | ||||||
| Pullus | 11-05-2023 | 5.556.464 | r-8S | -- | -- | -- | ||||||
| Pullus | 11-05-2023 | 5.556.465 | r-89 | -- | -- | -- | ||||||
| Pullus | 18-05-2023 | 5.556.465 | r-89 | 550 | -- | 80,4 | ||||||
| Pullus | 27-05-2023 | 5.556.464 | r-8S | dead > 7 days ago. | ||||||||
| Pullus | 18-06-2023 | r-89 | 1103 | 362 | 130,7 | |||||||
| XCHP | ||||
| dam: | dam 2 east | |||
| location: | below large boulders, east side of blocks, closer to bitumen than 2022. | |||
| breeders: | cach x cach | |||
| OBSERVATIONS: | ||||
| 04-04-2023 | adult: | yXCHP present with partner. | ||
| 05-04-2023 | adult: | yXCHP present with partner. | ||
| 09-04-2023 | adult: | 2 adult cach present. One is yXCHP. | ||
| nest: | 2 eggs measured. No watertest, ring chicks in 1st session. | |||
| 26-04-2023 | nest: | 3 eggs, all measured. Red spot sprayed on stone. | ||
| 27-04-2023 | nest: | 3 eggs. | ||
| adult: | yXCHP present with partner. | |||
| 11-05-2023 | pulli: | 2 chicks ringed, 1 egg rotten | ||
| 13-05-2023 | adult: | yXCHP pictures. | ||
| 18-05-2023 | pulli: | R-89 present | ||
| 27-05-2023 | pulli: | dead chick near nest r-8S, dead >7 days. | ||
| 18-06-2023 | pulli: | r-89 present. Fledging success: 1 chick. | ||
| 25-05-2023 | pulli: | r-89 present with both parents | ||
Visits and data XCHP-2024:
| NEST code | parent 1 | parent 2 | A_length | A_width | A_volume | B_length | B_width | B_volume | C_length | C_width | C_volume | TOTAL NEST: | |
| XCHP 2024 | cach | cach | 70 | 52,6 | 97,51 | 69 | 52,8 | 96,85 | 68 | 51,6 | 91,16 | 285,53 | |
| # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | |||||||
| 3 | 10-4-2024 | 8-5-2024 | |||||||||||
| dam: | dam 2 east | ||||||||||||
| location: | below large boulders, east side of blocks, closer to bitumen than 2022. | ||||||||||||
| parents? | same as 2022, 2023 | ||||||||||||
| ring pulli: | 12-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 14-05-2024 | g-B|S | .5631170 | nest XCHP | PONT | 1CY | 200 | |||||||
| 14-05-2024 | g-B|T | .5631171 | nest XCHP | PONT | 1CY | 273 | |||||||
| OBSERVATIONS: | |||||||||||||
| 12-04-2024 | eggs: | 2, measured. | |||||||||||
| adults: | yXCHP & partner present | ||||||||||||
| 21-04-2024 | eggs: | 3 eggs, measured. | |||||||||||
| 23-04-2024 | adults: | yXCHP & partner present | |||||||||||
| 02-05-2024 | eggs: | 3 eggs. | |||||||||||
| 14-05-2024 | chicks: | 2x ringed and measured. | |||||||||||
| food: | Round Goby (zwartbekgrondel / Neogobius melanostomus) and worms. | ||||||||||||
| 04-06-2024 | adult: | y-XCHP & partner present and aggressive. | |||||||||||
| 18-06-2024 | chick: | CONTROLL: g-B|T at water. | |||||||||||
below: Caspian Gull cachinnans hybrid XCHP 8CY, April 12 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.
below: Caspian Gull cachinnans hybrid XCHP 8CY, March 16 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.
below: Caspian Gull cachinnans hybrid XCHP 7CY, October 13 2024, Nieuwpoort beach, Belgium. Picture: Pascal Lepretre.
below: Caspian Gull cachinnans hybrid XCHP 7CY, March 25 2024, colony Lelystad, the Netherlands. Picture: Thijs Horst.
below: Caspian Gull cachinnans hybrid XCHP 7CY, January 16 2024, Almere - De Vaart, the Netherlands. Picture: Thijs Horst & Mars Muusse.
below: Caspian Gull cachinnans hybrid XCHP 6CY, July 08 2023, Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.
below: Caspian Gull cachinnans hybrid XCHP 6CY, April 05 2023, Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.
below: Caspian Gull cachinnans hybrid XCHP 6CY, April 05 2023, Lelystad, the Netherlands. Picture: Mars Muusse.
Breeding at the very same spot as last season.
below: Caspian Gull cachinnans hybrid XCHP 5CY, November 07 2022, Westkapelle, the Netherlands.
Iris turning paler, and note again rather short and high bill.
below: Caspian Gull cachinnans hybrid XCHP 5CY, July 17 2022, Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.
below: Caspian Gull cachinnans hybrid XCHP 5CY, June 21 2022, Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.
Here it is explained why we consider this bird to be hybrid.
below: Caspian Gull cachinnans hybrid XCHP 5CY, April 11 2022, Lelystad, the Netherlands. Picture: Mars Muusse.
below: Caspian Gull cachinnans hybrid XCHP 4CY, July 27 2021, Oostvaardersdijk - Lelystad, the Netherlands.
below: Caspian Gull cachinnans hybrid XCHP 3CY, July 10 2020, Oostvaardersdijk - Almere, the Netherlands.
below: Caspian Gull cachinnans hybrid XCHP 1CY, December 07 2018, Le Portel, France.
Classic cachinnans in all aspects, at this age.
