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 008
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 008-2020 positioned on open tarmac patch (but next to Elderberry) of breakwater 1 west of T-split.
- Nest 008-2024 positioned on open tarmac patch (but next to Blackberry) of breakwater 1 opposite harbour.
- Certainty on ID in 2020, breeders are Caspian Gull cachinnans, one partner is ringed green XLDT from Germany, and one unringed partner.
- In 2021 we did not find back g-XLDT in the colony, despite its presence at a nearby waste treatment plant in February 2021.
- ID 2024: again green XLDT at dam 1, together with brutal male Caspian Gull cachinnans.
| location | Nest location on April 15th, 2020. | Nest location on April 27th, 2020. | May 02 2024: new location at dam 1. |
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| eggs | Eggs April 15th, 2020: 2 eggs clutch. | Eggs April 27th, 2020: 3 eggs clutch. | May 02 2024: 3 eggs. |
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| partner 1 | May 7th, 2020: cachinnans g[XLDT]. | May 7th, 2020: cachinnans g[XLDT]. | April 15th, 2020: cachinnans g[XLDT]. |
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| partner 1 | April 15th, 2020: cachinnans g[XLDT]. | May 02 2024: cachinnans g[XLDT]. | May 02 2024: cachinnans g[XLDT]. |
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| partner 2 | May 7th, 2020: cachinnans unringed. | April 15th, 2020: cachinnans unringed. | May 02 2024: unringed male cachinnans. |
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| pullus | April 27th, 2020: n[F|L]. HY=2019. | . | . |
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| pullus | May 14th, 2024: pullus g-C|K. | May 14th, 2024: pullus g-C|L. | May 14th, 2024: pullus g-C|M. |
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| food | May 14th, 2024: 14x fish around nest. | . | . |
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Visits and data.
| datum: | egg no: | width (mm) | length (mm) | volume (cm3): | water test on April 27th: | |
| 15-04-2020 | A | 50,8 | 74 | 96,15 | 90 - floating, 2mm above surface | 2 eggs in nest. |
| 15-04-2020 | B | 50,1 | 74,2 | 93,77 | 90 - floating, 1mm above surface | |
| 27-4-2020 | C | 50,7 | 71,6 | 92,67 | 90 - hafway in water | 3rd egg now as well in nest. |
| sum nest: | 282,59 | |||||
| 07-05-2020 | eggs | B-egg start to hatch. | ||||
| 21-05-2020 | -- | Nest unsuccessful. No left-overs, no shit, no chicks, no alarming parents. | ||||
| 02-06-2020 | -- | Nest empty, but parents still around. | ||||
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: | |
| XLDT 2024 | cach | cach | 73 | 49,9 | 91,52 | 76,3 | 49,7 | 94,89 | 76,7 | 51 | 100,45 | 286,86 | |
| # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | |||||||
| 3 | 25-4-2024 | 23-5-2024 | |||||||||||
| dam: | dam 1 west | ||||||||||||
| location: | Opposite the harbour | ||||||||||||
| parents? | g-XLDT & male cach | ||||||||||||
| ring pulli: | 28-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 14-05-2024 | g-C|K | .5631104 | nest XLDT | PONT | 1CY | 158 | |||||||
| 14-05-2024 | g-C|L | .5631105 | nest XLDT | PONT | 1CY | 126 | |||||||
| 14-05-2024 | g-C|M | .5631106 | nest XLDT | PONT | 1CY | 88 | |||||||
| OBSERVATIONS: | |||||||||||||
| 02-05-2024 | adults: | XLDT & male cachinnans at nest site, incubating male. Attempt to trap male, failed. | |||||||||||
| eggs: | 3x, measured. | ||||||||||||
| 14-05-2024 | chicks: | 3x ringed. Fish bolus (yellow) when processed. | |||||||||||
| food: | 14x fishes: among other Perch, Roach, Goby. | ||||||||||||
| 18-06-2024 | chicks: | 3x chicks present at dam. With unringed father & g-XLDT. | |||||||||||