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 056
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 056 positioned high on breakwater dam 2, near black table (flotsam and jetsam nearby nest), hence nest called "black table nest".
- ID certain in 2021, both parent's characteristics match pure Caspian Gull cachinnans.
- ID certain in 2024, both parent's Caspian Gull cachinnans. Trapped female in May 2024, now g-A|3.
| location | Nest "black table" on top of dam April 26th, 2021. | Nest April 24th, 2021: 3 eggs clutch. | Nest 15th, 2021: 1 hatched chick & 2 eggs. |
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| April 21st, 2024: full clutch, with 3 eggs. | April 21st, 2024: full clutch, with 3 eggs. | . | |
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| partner 1 | April 24th, 2021: cachinnans parent, moulting. | April 24th, 2021: cachinnans parent, moulting. | April 24th, 2021: cachinnans parent, moulting. |
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| partner 1 | April 26th, 2021: cachinnans parent, moulting. | April 21st, 2024: cachinnans male. | April 21st, 2024: cachinnans male. |
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| partner 1 | April 23 2024: cachinnans male. | April 23 2024: cachinnans male. | April 23 2024: cachinnans male. |
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| partner 2 | May 13th, 2021: cachinnans parent. | May 13th, 2021: cachinnans parent. | April 21st, 2024: cachinnans female. |
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| May 7th, 2024: cachinnans female, now g-A|3. | May 02 2024: female cachinnans. | May 02 2024: female cachinnans. | |
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Visits and data 2021.
| date | ||||||
| 16-04-2021 | Patrolling adult and landing at location. We did not climb the dam to search. | |||||
| 24-04-2021 | 3 eggs | egg no: | width (mm) | length (mm) | volume (cm3): | water test on April 24th: |
| A | 50,5 | 71,1 | 91,30 | 20 - flat on bottom | ||
| B | 49,8 | 67,2 | 83,91 | 30 - flat on bottom | ||
| C | 48,4 | 63,3 | 74,66 | 20 - flat on bottom | ||
| sum nest: | 249,87 | |||||
| 26-04-2021 | Moulting parent attacks from nest and start patrolling. | |||||
| 13-05-2021 | Partner 2 at nest and aggressive. Do they have chicks maybe? | |||||
| 15-05-2021 | 2 eggs in nest. | |||||
| 1 hatched chick (1 day old). Mass = 61 gr. | ||||||
| 28-05-2021 | 1 egg rotten in nest. | |||||
| Alarming parent, but chicks not found in dense vegetation, despite intense search. | ||||||
| 08-06-2021 | No birds present. | |||||
| 26-06-2021 | No chicks found. | |||||
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: | |
| cach | cach | 74,5 | 48 | 86,42 | 71,7 | 49,5 | 88,46 | 71,9 | 49,2 | 87,63 | 262,51 | ||
| 056-2024 | # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | ||||||
| 3 | 10-4-2024 | 8-5-2024 | |||||||||||
| dam: | dam 2 east | ||||||||||||
| location: | was Black table 2020/2021, 15 mtr E of 17B, now with white jerrycan | ||||||||||||
| parents? | New? | ||||||||||||
| ring pulli: | 12-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | 07-05-2024 | g-A|3 | .5631237 | 56 black table | PONT | F | >4CY | 449 | 1030 | 131,5 | 60,1 | 71,2 | 20,3 | 7 |
| OBSERVATIONS: | |||||||||||||
| 21-04-2024 | eggs: | 3 eggs, measured. | |||||||||||
| adult: | 2x Caspian Gull: incubating and guarding. | ||||||||||||
| 02-05-2024 | eggs: | 3 eggs. | |||||||||||
| 07-05-2024 | adult: | 1x trapped at nest. Food: pork chop & chicken drumstick (likely landfill feeder) | |||||||||||