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 g-N|V (167-2025)
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 167 positioned on section "dam 1 blocks", just 2,5 meters south of nest y-P:U60. Nest visible from south side. Discovered late in season 2023.
- In 2024 & 2025: same location.
- ID certain in 2023: both parents are sub-adult Caspian Gull cachinnans.
- ID uncertain in 2024: one parent is adult Caspian Gull cachinnans. Other unknown, but likely Caspian.
- ID certain in 2025: both parents are adult Caspian Gull cachinnans. female ringed this year: g-N|V.
| nest | May 13th, 2023: 2 eggs & 1 chick hatching. | April 12th, 2024: 3 eggs clutch. | May 31st, 2024: nest 167. |
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| nest | April 23 2025: 3 eggs (full clutch). | April 23 2025: 3 eggs (full clutch). | . |
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| partner 1 | May 13th, 2023: 5CY cachinnans. | May 13th, 2023: 5CY cachinnans. | May 13th, 2023: 5CY cachinnans. |
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| partner 1 | May 13th, 2023: adult cachinnans. | June 04 2024: 2 parents at nest. | May 01 2025: adult cachinnans g-N|V. |
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| partner 1 | May 01 2025: adult cachinnans g-N|V. | May 01 2025: adult cachinnans g-N|V. | May 05 2025: adult cachinnans g-N|V. |
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| partner 2 | May 13th, 2023: adult cachinnans. | May 13th, 2023: adult cachinnans. | May 13th, 2023: adult cachinnans. |
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| partner 2 | May 13th, 2023: sub-adult cachinnans. | May 05 2024: adult cachinnans. | May 08 2025: adult cachinnans. |
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| pullus | June 25th, 2023: juvenile g[7|E]. | June 25th, 2023: juvenile g[7|F]. | May 7th, 2024: chick g-A|4. |
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| pullus | May 31 2024: chick g-A|5. | June 18th, 2024: chick g-A|7. | June 09 2025: adult cachinnans g-T|7. |
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| pullus | June 25 2025: adult cachinnans g-T|8. | . | . |
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Visits and data 2023:
| egg sizes & volume 2023 | ||||||
| SPECIES | NEST | |||||
| cach x cach | 167-2023 | |||||
| ring pulli: May 18th. | ||||||
| catch: | date: | metal: | darvic: | mass: | wing: | head+bill: |
| pullus | 18-5-2023 | 5556497 | G-7|E | 167 | 60,5 | |
| pullus | 18-5-2023 | 5556498 | G-7|F | 123 | 56,4 | |
| pullus | 18-6-2023 | g-7|E | ||||
| pullus | 18-6-2023 | g-7|F | ||||
| 167-2023 | NEW NEST | ||
| dam: | dam 1 | ||
| location: | Blocks dam 1 - 2,5 mtr SW of PU60. Visible from South. | ||
| breeders: | cach x cach | ||
| OBSERVATIONS: | |||
| 13-05-2023 | eggs | 1 egg, 1 egg hatching, 1 small pullus | |
| 13-05-2023 | adult | partner 2 = partner 1 nest 26-2022, that time 4cy cach. | |
| 18-05-2023 | pulli: | 2 chicks ringed, 3rd dead in nest | |
| 18-06-2023 | adult | partner 1 with chicks. | |
| 18-06-2023 | pulli: | both chicks g-7|E & g-7|F present. | |
| 25-06-2023 | pulli: | both chicks g-7|E & g-7|F present. Two chicks fledged. | |
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: | |
| 167-2024 | cach | 77,3 | 53 | 109,33 | 76,5 | 52,6 | 106,57 | 74,3 | 52,3 | 102,33 | 318,22 | ||
| # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | |||||||
| 3 | 8-4-2024 | 3-5-2024 | |||||||||||
| dam: | dam 1 blocks | ||||||||||||
| location: | Blocks dam 1 - 2,5 mtr SW of PU60. Visible from South. | ||||||||||||
| parents? | same as 2023? | ||||||||||||
| ring pulli: | 09-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 07-05-2024 | g-A|4 | .5631238 | 167 | PONT | 1CY | 150 | |||||||
| 07-05-2024 | g-A|5 | .5631239 | 167 | PONT | 1CY | 160 | |||||||
| 07-05-2024 | g-A|7 | .5631240 | 167 | PONT | 1CY | 162 | |||||||
| 04-06-2024 | g-A|4 | .5631238 | 167 | PONT | 1CY | 291 | 1007 | 113,2 | |||||
| OBSERVATIONS: | |||||||||||||
| 12-04-2024 | eggs: | 3 eggs, measured. Long, and brown. | |||||||||||
| 21-04-2024 | eggs: | 3 eggs, not measured. | |||||||||||
| 07-05-2024 | chicks: | 3x ringed. | |||||||||||
| 17-05-2024 | chicks: | g-A|7 with parent Caspian Gull. | |||||||||||
| 31-05-2024 | chicks: | 3x chicks & parents Caspian Gulls. | |||||||||||
| 04-06-2024 | chicks: | g-A|4 present, measured. Also present: g-A|5. | |||||||||||
| adult: | 2x Caspian Gull present. | ||||||||||||
| 18-06-2024 | chick: | CONTROLL: g-A|7 at water, g-A|4 & g-A|5 at nest site. | |||||||||||
Visits and data 2025 nest g-N|V (167).
| 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 |
| g-N|V (167) | cach | cach | 74,3 | 52,7 | 73 | 53,4 | 72,3 | 53 | 3 | ||||
| dam: | dam 1 blocks | ||||||||||||
| location: | Behind PU60-2024, same location as 2024. Code sprayed on block again.
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| parents: | same as 2024. This season trapped the female, now g-N|V. | ||||||||||||
| ringed: | |||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 01-05-2025 | g-N|V | 5641024 | 167 | PONT | F | >4CY | 452 | 970 | 131,3 | 57,8 | 69,2 | 17,2 | 7 |
| 25-05-2025 | g-T|7 | 5641863 | 167 | PONT | pullus | 960 | ringed pullus | ||||||
| 25-05-2025 | g-T|8 | 5641864 | 167 | PONT | pullus | 948 | ringed pullus | ||||||
| 09-06-2025 | G-T|7 | 5641863 | PONT | pullus | 1026 | CONTROL | |||||||
| 09-06-2025 | G-T|8 | 5641864 | PONT | pullus | 1026 | CONTROL | |||||||
| OBSERVATIONS: | |||||||||||||
| 23-04-2025 | eggs | 3 eggs, measured
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| 28-04-2025 | eggs | 3 eggs | |||||||||||
| 01-05-2025 | eggs | 3 eggs, 2x hatching
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| adult | trapped adult with Chinaloop
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| 08-05-2025 | adult | unringed partner present
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| 13-05-2025 | chicks | 1x dead chick, others not found
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| food | 2x duckling on nest
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| 25-05-2025 | chicks | 2 chicks ringed | |||||||||||
| 09-06-2025 | chicks | g-T|7 and T|8 found and measured, both fledged.
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