Larus cachinnans in the Netherlands
(last update: August 16, 2020)
Albert de Jong
Leon Kelder
Roland-Jan Buijs
Thijs Horst
Merijn Loeve
Mars Muusse
Cachinnans - nest r-6M (270-2025)
General remarks:
- Eggs: Volume measured by Stonehouse (1964) and Spaans & Spaans (1975), which make comparison possible with data from Texel (Camphuysen pers comm 16.04.2020).
- Nest r-6M positioned on dam 2 central section, 3 meters east of Black Table, top of dam (only visible from N-side), White football "Derbystar" near nest.
- ID certain in 2025: male is 4CY cachinnans r-6M (from nest 139-2022), and female is adult cachinnans.
| location | April 21 2025: nest with 2 eggs. | April 21 2025: nest with 2 eggs. | . |
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| partner 1 | May 31 2025: male 4CY cachinnans r-6M. | April 01 2025: male 4CY cachinnans r-6M. | April 01 2025: male 4CY cachinnans r-6M. |
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| partner 2 | April 25 2025: female Caspian Gull. | April 25 2025: female Caspian Gull. | April 25 2025: female Caspian Gull. |
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| partner 2 | May 31 2025: pair cachinnans, with male r-6M. | May 31 2025: pair cachinnans, with male r-6M. | '. |
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Data for nest r-6M in 2025 (270):
| 2025 | parent 1 | parent 2 | A_length | A_width | A_volume | B_length | B_width | B_volume |
| r-6M (270) | cach | cach | 73,3 | 49,9 | 70,9 | 58,9 | ||
| dam: | dam 2 centraal | |||||||
| location: | 3 meters east of Black Table, top of dam (only visible from N-side). White football near nest. Football 'Derbystar' placed next to nest.
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| parents: | new: r-6M and female cach.
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| OBSERVATIONS: | ||||||||
| 4/21/2025 | eggs | 2x eggs measured.
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| 4/23/2025 | adult | r-6M and unringed Caspian present. Attempt to trap breeding adult. Failed.
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| eggs | still 2 eggs. | |||||||
| 5/8/2025 | adult | both partners present.
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