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
Cachinnans - nest Lelystad nest g-N|R & br-BJ (230-2025).
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 230 positioned on dam 2, west. 2 mtr S of lighthouse dam 2. Nest of Herrings, is part of "Herring Gull control group".
- ID certain in 2022: both are argenteus.
- ID certain in 2023: both are argenteus.
- ID certain in 2024: both are argenteus.
- ID certain in 2025: female argenteus, ringed in 2025, now b/r-JB. Male is 5CY cachinnans, ringed in 2025, now g-N|R. Chicks are F1 hybrids.
| nest | April 29th, 2022: location of nest. | April 29th, 2022: full clutch, 3 eggs. | April 21st, 2024: 2 eggs. |
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| nest | April 23 2025: 2 eggs. | April 23 2025: 2 eggs. | May 05 2025: Caspian Gull g-N|R & Herring Gull b/r-JB. |
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| partner 1 | April 27th, 2023: adult Herring Gull. | May 1st, 2022: 2 Herring Gulls. | April 23 2025: male 5CY Caspian Gull. |
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| partner 1 | April 23 2025: male 5CY Caspian Gull. | May 01 2025: 5CY male Caspian Gull g-N|R. | May 01 2025: 5CY male Caspian Gull g-N|R. |
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| partner 2 | April 28th, 2025: Herring Gull b/r-JB. | April 28th, 2025: Herring Gull b/r-JB. | April 28th, 2025: Herring Gull b/r-JB. |
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| chicks | May 27th, 2023 pullus g[8|H]. | June 04 2024: chick b/w-AX. | May 31 2025: chick g-R|B. |
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| chicks | May 31 2025: chick g-R|C. | . | . |
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Visits and data 2022.
| nest 230Z-2022 | date A egg: April 24 | hatch A egg: May 22 | ring chicks: May 31 | |||
| 29-04-22 | 3 eggs | A egg | 69,4 | 48,3 | tip bottom - 30 gr | 2 mtr S of lighthouse dam 2. Nest of Herrings. |
| B egg | 67,6 | 47 | tip bottom - 40 gr | between bricks, red spot sprayed. | ||
| C egg | 70,6 | 48 | tip bottom - 30 gr | |||
| 01-05-22 | 2 adults at nest. | |||||
| 17-05-22 | 3 eggs. | |||||
| 17-06-22 | 2 adults and (at least) 2 chicks. | |||||
| 21-06-22 | 2 adults and (at least) 2 chicks. | |||||
| 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? |
| teus x ? | 230Z-2023 | 70,8 | 50,7 | 91,63 | 69 | 48,6 | 82,06 | 68 | 48,6 | 80,87 | 254,56 | No. |
| ring pulli: May 25 | laying A egg: April 20 | hatch A egg: May 18 | ||||||||||
| catch: | date: | metal: | darvic: | mass: | wing: | head+bill: | ||||||
| pullus | 27-05-2023 | 5.625.257 | g-8|H | 211 | ||||||||
| 230Z-2023 | was Herring Gull in 2022 | |||||
| dam: | dam 2 west | |||||
| location: | 2 mtr S of lighthouse. Close to nest X60J-2023 | |||||
| breeders: | teus x ? (probably teus x teus) | |||||
| OBSERVATIONS: | Water test: | |||||
| 26-04-2023 | nest: | 3 eggs. Measured & water test: | A | 20 - tip bottom | ||
| B | 20 - tip bottom | |||||
| 27-04-2023 | adult: | breeding ad Herring | C | 30 - tip bottom | ||
| 11-05-2023 | pullus: | r-77 in this nest? Should be from X60J? > Yes, from y-X60J. | ||||
| 27-05-2023 | pullus: | 1x chick ringed. | ||||
Visits and data 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: | |
| 230Z-2024 | teus | teus | 69,4 | 50 | 87,36 | 68,1 | 48,8 | 81,66 | 67,2 | 47,1 | 75,06 | 244,07 | |
| # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | |||||||
| 21-4-2024 | 19-5-2024 | ||||||||||||
| dam: | dam 2 west | ||||||||||||
| location: | 3 mtr south of lighthouse, Herring nest. | ||||||||||||
| parents? | Same as 2023. | ||||||||||||
| ring pulli: | 24-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 04-06-2024 | b/w-AX | .5631006 | Dam 2 torentje | Zilver | 1CY | 93 | 428 | 82,7 | |||||
| OBSERVATIONS: | |||||||||||||
| 31-03-2024 | nest: | nest is empty. | |||||||||||
| 21-04-2024 | eggs: | 2 eggs, measured. | |||||||||||
| 26-04-2024 | eggs: | C egg measured. | |||||||||||
| 07-05-2024 | eggs: | 3 eggs, not measured. | |||||||||||
| 14-05-2024 | eggs: | 3 eggs. | |||||||||||
| 04-06-2024 | chicks: | 1x ringed. | |||||||||||
Visits and data 2025 for nest g-N|R & br-BJ (230).
| 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 | |
| g-N|R & br-BJ | cach | teus | 73,4 | 53,2 | 72,1 | 52,5 | 72,7 | 51 | 3 | |||||
| (230) | ||||||||||||||
| dam: | dam 2 west
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| location: | 3 m S of lighthouse, Was 230Z-2024
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| parents: | new, with Caspian Gull this season. Both partners trapped and ringed. Male 5CY Caspian is g-N|R. Female Herring Gull is b/r-JB. | |||||||||||||
| ringed: | ||||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | |
| 28-04-2025 | b/r-JB | 6254497 | nest 230 | HERRING | F | >4CY | 428 | 895 | 110,8 | 48,1 | 65,6 | 18,6 | 5 | |
| 01-05-2025 | g-N|R | 6254558 | br-BJ (230) | PONT | M | >4CY | 453 | 1219 | 143,1 | 65,2 | 74,8 | 21,1 | 7 | 25B00657
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| 31-05-2025 | g-R|B | 5641887 | g-N|R & b/r-JB | HYBRID | pullus | 380 | 81,7 | |||||||
| 31-05-2025 | g-R|C | 5641888 | g-N|R & b/r-JB | HYBRID | pullus | 306 | 78 | |||||||
OBSERVATIONS:
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| 21-04-2025 | eggs | 1 egg. Assumed to be of Herring Gull, but proved wrong in the next week. Is Caspian.
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| 23-04-2025 | eggs | 2 eggs, measured.
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| adult | male 5CY cachinnans. Attempt to trap it. Failed.
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| 28-04-2025 | adult | male is 5CY cachinnans. Female is adult Herring Gull.
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| adult | trapped female HG, now b/r-JB. was Herring from nest nest 19-2024 at dam 1.
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| 01-05-2025 | adult | trapped 5CY male Caspian Gull, now g-N|R. | ||||||||||||
| 08-05-2025 | adult | both partners present.
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| 13-05-2025 | nest | 3x eggs. | ||||||||||||
| 31-05-2025 | nest | 2 chicks ringed, 3rd not found. Eventually, no chicks fledged in this nest.
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