Larus cachinnans in the Netherlands
(last update: August 16, 2020)
Albert de Jong
Merijn Loeve
Roland-Jan Buijs
Thijs Horst
Leon Kelder
Mars Muusse
Cachinnans - nest Lelystad n-F|8
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 n-F|8 positioned on dam 2: central, 8 mtr NW of 17, only visible from N side. Same location for 2023 - 2025.
- ID certain in 2023: male is 4CY n-F|8 and partner is adult female cachinnans.
- ID certain in 2024: male is 5CY n-F|8 and partner is adult female cachinnans.
- ID certain in 2025: male is 6CY n-F|8 and partner is adult female cachinnans.
| nest | April 21st, 2024: 1 egg. | March 31 2024: n-F|8 & partner at nest. | April 23rd, 2024: orange crate. |
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| nest | April 21 2025: 3 eggs. Exact same nest site. | April 21 2025: 3 eggs. Exact same nest site. | . |
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| partner 1 | April 27 2023: n-F|8 at dam 2. | April 27 2023: n-F|8 at dam 2. | May 13 2023: n-F|8. |
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| May 13 2023: n-F|8.. | March 25 2024: n-F|8. | April 23rd, 2024: n-F|8. |
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April 23rd, 2024: n-F|8. |
April 23rd, 2024: n-F|8. |
February 16 2025: early bird n-F|8. |
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| partner 2 | March 25 2024: n-F|8 & unringed partner. | April 23rd, 2024: female partner n-F|8. |
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| chicks | Fledged juvenile g-7|Y, June 25 2023. | Fledged juvenile g-8|A, June 25 2023. | May 31 2024: chick g-C|8. |
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| chicks | July 09 2025: fledged juvenile g-R|L. | June 30 2025: fledged juvenile g-R|M. | . |
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| food | May 14th, 2024: fish prey = Goby. | . | . |
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Visits and data 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 | nF|8 | 72,2 | 52,2 | 99,06 | 71,1 | 49,1 | 86,30 | 71 | 51,1 | 93,35 | 278,71 | new nest |
| ring pulli: -- | laying A egg: -- | hatch A egg: -- | ||||||||||
| catch: | date: | metal: | darvic: | mass: | wing: | head+bill: | ||||||
| Pullus | 18-05-2023 | 5.556.417 | g-7|Y | 163 | -- | 64,3 | ||||||
| Pullus | 27-05-2023 | 5.556.417 | g-7|Y | 470 | -- | -- | ||||||
| Pullus | 27-05-2023 | 5.625.191 | g-8|A | 487 | -- | -- | ||||||
| n-F|8 | ||||||||
| dam: | dam 2 central. | |||||||
| location: | Dam 2 central, 8 mtr NW of 17, only visible from N side. Behind red crate, close to bushes. Code sprayed. | |||||||
| breeders: | cach x cach | |||||||
| OBSERVATIONS: | ||||||||
| 27-04-2023 | adult: | |||||||
| 30-04-2023 | nest: | 3 eggs. Measured. Watertest: | A: 1 mm - floating | |||||
| adult: | nF8 breeding. Later: unringed partner. Both large birds. | B: 2 mm - floating | ||||||
| 11-05-2023 | nest: | 3 eggs hatching | C: 1/2 way - floating | |||||
| 18-05-2023 | pulli: | 1 chick ringed, other 2 not found | ||||||
| 27-05-2023 | pulli: | 1x control, 1x new chick ringed | ||||||
| 25-06-2023 | pulli: | g-7|Y, g-8|A and n-F|8 present | ||||||
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: | |
| n-F|8 2024 | cach | cach | 72 | 50,2 | 91,36 | 0,00 | 0,00 | 91,36 | |||||
| # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | |||||||
| 3 | 21-4-2024 | 19-5-2024 | |||||||||||
| dam: | dam 2 central | ||||||||||||
| location: | is n-F|8 - 2023, orange crate | ||||||||||||
| parents? | n-F|8 and partner 2023? | ||||||||||||
| ring pulli: | 24-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 31-05-2024 | g-C|8 | .5631132 | n-F|8 | PONT | 1CY | ||||||||
| OBSERVATIONS: | |||||||||||||
| 25-03-2024 | adult: | n-F|8 near nest site 2023. | |||||||||||
| 31-03-2024 | adult: | n-F|8 & partner near nest site 2023. | |||||||||||
| 21-04-2024 | eggs: | 1 egg, measured | |||||||||||
| 23-04-2024 | adult: | n-F|8 & partner near nest. | |||||||||||
| 26-04-2024 | eggs: | still only 1 egg. | |||||||||||
| 07-05-2024 | nest: | 1 tiny chick, not ringed. | |||||||||||
| 14-05-2024 | nest: | no chick found. | |||||||||||
| food: | 2x Round Goby & 1x Perch. | ||||||||||||
| 31-05-2024 | chicks: | 1x ringed. Is only chick. | |||||||||||
| 18-06-2024 | nest: | 2x adults present. g-C|8 dead. Failed season. | |||||||||||
Visits and data 2025.
| 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: | . | # eggs |
| n-F|8 | cach | cach | 72,4 | 51,6 | 72,1 | 50,7 | 71 | 52,1 | 3 | |||||
| dam: | dam 2 central, N-side | |||||||||||||
| location: | is n-F|8 - 2023-2024, orange crate
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| parents: | same as 2024
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| ringed: | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | |
| 31-05-2025 | g-R|L | 5641902 | n-F|8 | PONT | pullus | 818 | Ringed pullus
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| 31-05-2025 | g-R|M | 5641903 | n-F|8 | PONT | pullus | 772 | Ringed pullus
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| 09-06-2025 | G-R|L | 5641902 | PONT | pullus | 905 | CONTROL | ||||||||
OBSERVATIONS:
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| 16-03-2025 | nest | n-F|8 & partner near orange crate, location 2023-2024, North side dam 2, near nest 17,
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| 21-04 | eggs | 3x eggs measured,
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| 08-05 | adult | unringed partner present
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| 31-05 | chicks | 2x chicks ringed, 1 egg unfertile
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| food | mutiple fishes in nest, and feeding stone full of fish scraps,
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| 09-06 | chicks | g-R|L caught and measured
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