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 Lelystad g-A|N (099)
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 099 positioned on artificial breakwater 1 west. Location is near Blackberry top of dam, 50 mtr E of r-7P. Code 99 sprayed on tarmac.
- Uncertainty on ID in 2024, one Herring Gull argenteus and one Caspian Gull cachinnans.
| location | April 21st, 2024: far west on dam 1. | April 21st, 2024: far west on dam 1. | April 21st, 2024: 1 egg. |
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| partner 1 | April 21st, 2024: Herring Gull and Caspian-type. | April 21st, 2024: Caspian-type. | May 02 2024: trapped Caspian Gull male, g-A|N. |
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| partner 1 | June 29 2025: male Caspian Gull g-A|N. | August 20 2025: male Caspian Gull g-A|N. | . |
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| partner 2 | May 02 2024: Herring Gull female. | May 02 2024: Herring Gull female. | May 02 2024: Herring Gull female. |
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| . | May 02 2024: Herring Gull female. | March 16 2025: pair Herring & Caspian Gull. | . |
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| pullus | May 14th, 2024: pullus g-C|V. | November 07 2025: hybrid chick g-R|U. | . |
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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: | |
| g-A|N | cach | teus | 81,9 | 48,1 | 95,41 | 0 | 0 | 0,00 | 0,00 | 95,41 | |||
| 099-2024 | # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | ||||||
| 20-4-2024 | 18-5-2024 | ||||||||||||
| dam: | dam 1 west | ||||||||||||
| location: | near Blackberry top of dam, 50 mtr E of r-7P. Code sprayed on tarmac. | ||||||||||||
| parents? | New | ||||||||||||
| ring pulli: | 22-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | 02-05-2024 | g-A|N | .5631218 | nest 99 dam 1 | PONT | M | >4CY | 455 | 1260 | 137 | 60,6 | 78,6 | 21,4 | 6 |
| 31-05-2024 | g-C|V | .5631121 | g-A|N (99) | cach x teus | 1CY | ||||||||
| 04-06-2024 | g-C|V | .5631121 | g-A|N (99) | cach x teus | 1CY | 64 | 324 | 75,0 | |||||
| OBSERVATIONS: | |||||||||||||
| 21-04-2024 | eggs: | 1 egg, measured. | |||||||||||
| adult: | likely mixed pair | ||||||||||||
| 02-05-2024 | eggs: | 2 eggs. Will not be a full clutch. | |||||||||||
| adult: | female is Herring Gull. Male is Caspian Gull, trapped today. Now g-A|N. | ||||||||||||
| 31-05-2024 | chicks: | 1x ringed. | |||||||||||
| 04-06-2024 | chick: | g-C|V present. measured. | |||||||||||
Visits and data 2025 for nest g-A|N (099).
| 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-A|N (099) | cach | teus | 73,2 | 48,1 | 67 | 46,9 | 72 | 48,9 | 3 | |||||
| dam: | dam 1 south
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| location: | near Blackberry top of dam, 50 mtr E of r-7P, Code sprayed on tarmac
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| parents: | same as 2024, hybrid couple of Caspian Gull g-A|N & Herring Gull
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| ringed: | ||||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | |
| 31-05-2025 | g-R|U | 5641916 | g-A|N | HYBRID | pullus | 120 | ||||||||
| 09-06-2025 | g-R|U | 5641916
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g-A|N | HYBRID | pullus | 398 | CONTROL | |||||||
OBSERVATIONS:
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| 16-03-2025 | nest | g-A|N & female HG, like in 2024, nest 99
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| 21-03-2025 | nest | G-A|N & female HG, like in 2024, nest 99
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| 25-03 | nest | G-A|N & female HG, like in 2024, nest 99
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| 21-04 | nest | ready, but still empty
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| 13-05 | nest | 3x eggs measured, g-A|N trapped at nest while we aimed for the Herring Gull partner.
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| 31-05 | chicks | 1 chick ringed, 1 dead in nest and 1 failed egg
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| 09-06-2025 | chicks | g-R|U found and measured
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