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-CU & g-N|P (272).
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).
- In 2025: nest 272 positioned on dam 2 west section: is nest "Yellow Rope", between Blue Rope and nest 14. High on dam.
- ID certain in 2025: male is 4CY cachinnans r-CU (offspring nest 14-2022), and female is 5CY cachinnans trapped in 2025, now g-N|P.
- ID certain in 2026: male is unringed cachinnans and female is 6CY cachinnans g-N|P.
| location | April 23 2025: nest Yellow Rope. | April 23 2025: nest Yellow Rope. | April 22 2026: 3 eggs (full clutch). |
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| partner 1 | April 21 2025: 4CY male Caspian Gull r-CU. | May 08 2025: 4CY male Caspian Gull r-CU. | May 08 2025: 4CY male Caspian Gull r-CU. |
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| partner 2 | April 21 2025: 5CY female Caspian Gull. | May 01 2025: 5CY female Caspian Gull g-N|P. | May 01 2025: 5CY female Caspian Gull g-N|P. |
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| chicks | June 29 2025: chick g-C|0. Fledged. | . | . |
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Data for nest r-CU & g-N|P (272).
| 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:
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# eggs | |
| r-CU & g-N|P (272 Yellow Rope) |
cach | cach | 69 | 48,5 | 66,1 | 46,1 | 2 | |||||||
| dam: | dam 2 west
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| location: | Between Blue Rope and nest 14
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| parents: | new, r-CU is pullus 2022 of nest 14
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| ringed: | ||||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | |
| 01-05-2025 | g-N|P | 5641021 | r-CU & g-N|P | PONT | F | 5CY | 431 | 938 | 126 | 57,3 | 69,1 | 17,8 | 7,5 | |
| 31-05-2025 | g-C|0 | 5641923 | r-CU & g-N|P | PONT | pullus | 348 | ||||||||
OBSERVATIONS:
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| 16-03-2025 | adult | r-CU present, is 2022 chick from nest 14 (which is only 10 meters away!
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| 01-04 | adult | r-CU present
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| 12-04 | adult | r-CU present
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| 23-04 | eggs | 2 eggs, measured
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| adult | unringed female cachinnans
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| 01-05 | adult | trapped female cachinnans 5CY, now g-N|P.
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| eggs | 2x eggs | |||||||||||||
| 08-05 | adult | r-CU present
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| 13-05 | nest | 2x eggs | ||||||||||||
| 31-05 | nest | 1 chick ringed, other one not found
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Visits and data 2026.
| 2026 | parent 1 | parent 2 | A_length | A_width | A_volume | B_length | B_width | B_volume | C_length | C_width | C_volume | TOTAL NEST:
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# eggs | |
| g-N|P (272) | cach | cach | 73,4 | 49,4 | 72,4 | 48,5 | 72,1 | 48,0 | ||||||
| ringed: | ||||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | tarsus | head+ bill | bill | gonys | mass | barcode | |
| 27-04-2026 | g-N|P | CONTROLL | Blue Rope | 26B02660 | ||||||||||
OBSERVATIONS:
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| 22-04-2026 | nest | 3 eggs, measured. | ||||||||||||
| parents | Unringed male Caspian, female is Caspian g-N|P. This season r-CU not seen. | |||||||||||||
| 26-04-2026 | nest | 3 eggs, | ||||||||||||
| 27-04-2026 | parents | Attempt to trap unringed male Caspian. Instead, we trapped g-N|P again. | ||||||||||||