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 034
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 034 positioned at breakwater 1, called "branch-nest" (3 white stripes on dead branch), between y[PNED] and T-split. Two meters from nest 33.
- ID in 2020 certain, male is Caspian Gull cachinnans, female is Herring Gull argenteus.
- Same pair in 2021.
- Same pair in 2022.
| location | May 7th, 2020: nest location - stripes on branch. | March 23rd, 2021: nest location - stripes on branch. | March 27th, 2022: nest location - stripes on branch, coded 130. |
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| nest | May 7th, 2020: 3 eggs. | March 27th, 2022: 3 eggs. | |
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| partner 1 | May 7th, 2020: female argenteus. | May 7th, 2020: female argenteus x male cachinnans. | March 23rd, 2021: female argenteus. |
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| partner 2 | May 7th, 2020: male cachinnans. | May 7th, 2020: male cachinnans. | March 23rd, 2021: male cachinnans. |
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| March 27th, 2022: male cachinnans. | March 27th, 2022: male cachinnans. | March 27th, 2022: male cachinnans. | |
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| pullus | May 21st, 2021: pullus b[F|8]. | May 21st, 2021: pullus b[F|9]. | May 21st, 2021: pullus b[F|+]. |
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| May 30th, 2022: one dead chick in nest. | May 30th, 2022: one chick ringed r-7.G. | August 19th, 2022: Almere, r-7.G fledged. | |
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Visits and data.
| date: | egg no: | width (mm) | length (mm) | volume (cm3): | water test on May 7th: | |
| 07-05-2020 | A | 50,8 | 70,3 | 91,34 | 90 - tip at bottom. | 3 eggs in the nest, one partner argenteus, one partner cachinnans. |
| B | 49,8 | 73,9 | 92,28 | 90 - tip at bottom. | ||
| C | 47,3 | 76,3 | 85,95 | 90 - tip at bottom. | ||
| sum nest: | 269,57 | |||||
| 21-05-2020 | eggs | Still 3 eggs present. | ||||
| date: | ||||||
| 24-03-2021 | 2 adults at this location. | |||||
| 06-05-2021 | 2 adults guarding at blocks. Red flag "71" placed to mark location. | |||||
| egg no: | width (mm) | length (mm) | volume (cm3): | water test on May 6th: | ||
| A | 50,7 | 74,5 | 96,42 | 90 - tip at bottom. | ||
| B | 50,3 | 70,3 | 89,56 | 90 - tip at bottom. | ||
| C | 50,4 | 71,1 | 90,93 | 90 - tip at bottom. | ||
| sum nest: | 276,91 | |||||
| 13-05-2021 | no visit, Camilla is trapping a Spoonbill. | |||||
| 15-05-2021 | nest with 3 eggs. Flag put up again, for it was not visible. | |||||
| metal ring | plastic | head + bill: | ||||
| 28-5-2021 | pullus | .5559422 | b-F|8 | 64 | ||
| pullus | .5559423 | b-F|9 | 52 | |||
| pullus | .5559424 | b-F|+ | 62 | |||
| 08-06-2021 | 1 adult at this location. All 3 chicks fledged. 100% success. | |||||
Visits and data 2022 for nest 34 (coded 130 on bitumen in 2022):
Estimation egg laying: A-egg = April 20 2022. Estimating hatching = May 18 2022.
| length (mm) | width (mm) | volume (cm3): | water test on April 27th: | ||||
| 27-04-2022 | A egg | 70,9 | 48,3 | -- | 20 gr - tip bottom | ||
| B egg | 73,6 | 50,3 | -- | 40 gr - tip bottom | |||
| C egg | 73 | 49,2 | -- | 40 gr - tip bottom | |||
| One parent is cachinnans (partner 1) | |||||||
| 17-05-2022 | female Herring Gull argenteus next to nest. | ||||||
| A egg: in tact. | |||||||
| C egg: with small hole. | |||||||
| B egg: hatched | |||||||
| metal | darvic | mass | wing | H+B | bill | ||
| 30-05-2002 | pullus | NLA 5625188 | r-7.G | 454 | 80 | 79,9 | 33,2 |
| One pullus dead in nest. | |||||||
| 28-06-2022 | image of r-7G. Together with female Herring gull and sibling (unringed). | ||||||
| 12-07-2022 | image of r-7G. | ||||||
| 17-07-2022 | image of r-7G. | ||||||