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 229 (was yX56A in 2023)
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 229 positioned on dam 2: 25 mtr east of lighthouse, old Spoonbill nest, between bushes = nest 229-2022 of sub-adults.
- ID certain in 2022: both immature (4CY) cachinnans.
- ID certain in 2023: location now occupied by female is y-X56A (from nest 206-2022). Partner is adult male cachinnans.
- ID certain in 2024: same spot with female y-X56A breeding. Partner is adult male cachinnans, which has no black on P4 this season.
| location | April 29 2022: nest location in bushes. | April 29 2022: old nest of Spoonbill. | April 27 2023: location of nest. |
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| April 21st, 2024: location of nest. | April 23rd, 2024: X56A, Egret & Spoonbills. | . | |
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| eggs | April 29 2022: 2 eggs. | May 11 2023: egg hatching. | April 21st, 2024: full clutch, with 3 eggs. |
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| partner 1 | April 29 2022: with tiny mirror on P9. | June 17, 2022: partner 1. | June 21, 2022: partner 1. |
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| partner 1 | May 13 2023: male cachinnans, was partner 1-2022? | May 13 2023: male cachinnans partner. | April 23rd, 2024: male cachinnans of X56A. |
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| partner 1 | April 23rd, 2024: male cachinnans of X56A. | April 23rd, 2024: male cachinnans of X56A. | . |
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| partner 2 | May 04 2022: both parents in territory (front is partner 2). | May 04 2022: parent 2 is cachinnans. | May 04 2022: cachinnans, with larger P9 mirror. |
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| partner 2 | April 09 2023: cachinnans y-X56A. | April 27 2023: cachinnans y-X56A. | April 27 2023: cachinnans y-X56A. |
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| partner 2 | March 08 2024: cachinnans y-X56A. | April 23rd, 2024: X56A, Egret & Spoonbills. | April 23rd, 2024: X56A. |
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| pullus | cachinnans r-7.Y fledged in 2023. | cachinnans r-7.8 fledged in 2023. | cachinnans g-7|U fledged in 2023. |
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| chick | June 18 2024: cachinnans g-B|W. | June 18 2024: Roach is food of g-B|W. | . |
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Visits and data:
| nest 229-2022 | date A egg: April 15 | hatch A egg: May 13 | ring chicks: May 22 | |||
| 29-04-22 | 2 eggs | A egg | 70,8 | 47,3 | tip bottom - 90 gr | flag placed on branch in bush. |
| B egg | 68,2 | 48,7 | tip bottom - 90 gr | old nest of Spoonbill, right in the bushes, 25 mtr E oif lighthouse. | ||
| 01-05-22 | 1 sub-ad cachinnans at nest 229. | |||||
| 04-05-22 | 2 sub-adult cachinnans both present at nest 229. | |||||
| 09-05-22 | 3 eggs | |||||
| 17-05-22 | 3 eggs, 3rd egg never measured. | |||||
| 17-05-22 | 2 sub-adults present, with 2x unringed chicks. | |||||
| partner 1 aggressive. | ||||||
| 21-06-22 | 2 parents + 2 unringed chicks. Conclusion: 2x fledged chicks from nest 229-2022. | |||||
| 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 | 229-2023 | 74 | 50 | 93,15 | 72,7 | 50,5 | 93,35 | 70,2 | 51,5 | 93,75 | 280,24 | X56A &cach |
| ring pulli: 15-mei | laying A egg: 10-apr | hatch A egg: 8-mei | ||||||||||
| catch: | date: | metal: | darvic: | mass: | wing: | head+bill: | ||||||
| pullus | 11-5-2023 | 5.556.455 | r-7Y | -- | -- | -- | ||||||
| pullus | 11-5-2023 | 5.556.456 | r-78 | -- | -- | -- | ||||||
| pullus | 18-5-2023 | 5.556.410 | g-7|U | 166 | -- | 63 | ||||||
| pullus | 18-5-2023 | 5.556.455 | r-7Y | 221 | -- | 65 | ||||||
| pullus | 27-5-2023 | 5.556.410 | g-7|U | 362 | -- | -- | ||||||
| pullus | 27-5-2023 | 5.556.455 | r-7Y | 499 | -- | -- | ||||||
| pullus | 25-6-2023 | 5.556.456 | r-78 | 1028 | 355 | 128,1 | ||||||
| 229-2023 | y[X56A] is breeding in 229 (X56A was at nest 206 in 2022) | |
| dam: | dam 2 west | |
| location: | 25 mtr east of lighthouse, old Spoonbill nest, between bushes = nest 229-2022 of sub-adults. | |
| breeders: | cach x cach | |
| OBSERVATIONS: | ||
| 09-04-2023 | y-X56A present north of dam. (27/4: yX56A not breeding at this nest in 2023). | |
| 26-04-2023 | eggs: | 3 eggs. Measured and water test: A/B/C:all are 90 - tip bottom. |
| nest: | code 229 sprayed on entrance block. | |
| 27-04-2023 | adult: | parent 1 = yX56A |
| 11-05-2023 | pulli: | 2 chicks ringed, 3rd egg hatching. |
| 13-05-2023 | adult: | partner 2 is cach. |
| 18-05-2023 | pulli: | 2 chicks present (R-7Y and unringed one, which is now ringed). |
| 27-05-2023 | pulli: | 2x ringed birds measured: g-7|U & r-7Y. |
| 18-06-2023 | adult: | ad yX56A easy at bread. |
| 25-06-2023 | pulli: | r-78 and g-7|U 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: | |
| X56A-2024 | cach | cach | 75,1 | 51,3 | 99,51 | 74,3 | 52 | 101,16 | 70,4 | 50,3 | 89,68 | 290,35 | |
| # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | |||||||
| 3 | 15-4-2024 | 13-5-2024 | |||||||||||
| dam: | dam 2 west | ||||||||||||
| location: | Between Spoonbills and Little Egret, was X56A-2023 | ||||||||||||
| parents? | same as 2023 | ||||||||||||
| ring pulli: | 18-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 14-05-2024 | g-B|W | .5631174 | nest X56A | PONT | 1CY | 159 | |||||||
| 14-05-2024 | g-B|X | .5631175 | nest X56A | PONT | 1CY | 120 | |||||||
| OBSERVATIONS: | |||||||||||||
| 08-03-2024 | adults: | yX56A on bread. | |||||||||||
| 20-03-2024 | adults: | yX56A on bread. | |||||||||||
| 21-04-2024 | eggs: | 3 eggs, measured. | |||||||||||
| adult: | X56A at nest. | ||||||||||||
| 23-04-2024 | adults: | yX56A leaves the nest | |||||||||||
| 02-05-2024 | eggs: | 3 eggs. | |||||||||||
| 07-05-2024 | eggs: | 3 eggs, not measured. | |||||||||||
| 14-05-2024 | chicks: | 2x ringed. | |||||||||||
| eggs: | 1x cold. |
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| 04-06-2024 | nest: | Much food low at blocks south. Probably chicks have moved to waterfront, but not found today. Y-X56A present at stones, and behind boat at bread. | |||||||||||
| 18-06-2024 | chicks: | g-B|W at water with 2x other juveniles. | |||||||||||
| food: | g-B|W trapped, food = fish (Roach). | ||||||||||||