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-M|9 & g-N|U
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).
- 2025: location on breakwater 2, end of pier at T-split dam 2. At foot of green lighthouse, a new nest in 2025.
- 2026: again at pier at T-split dam 2, but more central (50 mtr from lighthouse).
- ID in 2025 certain: both Caspian Gulls. Both ringed in 2025: male is g-M|9 and female is g-N|U.
- ID in 2026: same pair cachinnans, male is g-M|9 and female is g-N|U.
| location | April 28 2025, nest end dam 2 T split. | April 13 2026: 3 eggs in clutch. | . |
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| partner 1 | May 1st, 2025: female Caspian Gull g-N|U. | May 1st, 2025: female Caspian Gull g-N|U. | May 1st, 2025: female Caspian Gull g-N|U. |
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| partner 2 | April 28th, 2025: male Caspian Gull g-M|9. | April 28th, 2025: male Caspian Gull g-M|9. | April 28th, 2025: male Caspian Gull g-M|9. |
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| pullus | June 29th, 2025: chick Caspian Gull g-R|P. | . | . |
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Data for nest g-M|9 & g-N|U 2025.
| 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: | # eggs | |
| g-M|9 | cach | cach | 71,2 | 49,9 | 67,1 | 48,9 | 66,5 | 48,5 | 3 | |||||
| dam: | dam 2 T | |||||||||||||
| location: | end of pier at T-split dam 2, underneath green lighthouse, new nest.
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| parents: | New. Both Caspian Gulls trapped this season, now male is g-M|9 and female is g-N|U. | |||||||||||||
| ringed: | ||||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | |
| 28-04-2025 | g-M|9 | 6254495 | dam 2 lighthouse | PONT | M | >4CY | 463 | 1241 | 137,1 | 65,6 | 72,7 | 21 | ||
| 01-05-2025 | g-N|U | 5641023 | dam 2 lighthouse | PONT | F | 5CY | 443 | 966 | 122,5 | 55,1 | 70 | 18,2 | ||
| 31-05-2025 | g-R|P | 5641911 | g-M|9 en g-N|U | PONT | pullus | 522 | ringed pullus | |||||||
| 14-06-2025 | g-R|P | dam 2 WATER | PONT | pullus | 746 | CONTROL | ||||||||
| OBSERVATIONS: | ||||||||||||||
| 28-04-2025 | nest | 3 eggs, measured.
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| nest | male cachinans trapped on nest, now g-M|9
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| 01-05 | adult | trapped female, Male present as well
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| egg | 3x eggs | |||||||||||||
| 31-05 | chicks | trapped one chick, other 2 not found
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| 09-06 | chicks | g-R|P present and trapped, not measured
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| 14-06-2025 | chicks | g-R|P caught on water, probably only chick.
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Visits and data for nest g-M|9 & g-N|U 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-M|9 & g-N|U | cach | cach | 72 | 50,6 | 68,8 | 49,4 | 67,2 | 50,3 | 3 | |||||
| ringed: | ||||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | |
| 10-05-2026 | Y-0:U | .5646709 | g-M|9 & g-N|U | PONT | PULL | 81 | ||||||||
| 10-05-2026 | Y-0:V | .5646710 | g-M|9 & g-N|U | PONT | PULL | 121 | ||||||||
OBSERVATIONS:
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| 04-04-2026 | nest | 3 eggs, measured. Nest now 40 mtr towards centre of dam 2 Split. | ||||||||||||
| 27-04-2026 | parents | Both present. | ||||||||||||
| 10-05-2026 | pullus | 2x pullus ringed. 3rd chick not found. | ||||||||||||