Larus cachinnans in the Netherlands
(last update: August 16, 2020)
Albert de Jong
Merijn Loeve
Roland-Jan Buijs
Leon Kelder
Mars Muusse
Cachinnans - nest Lelystad 064 y[PHSV]
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 064 "PHSV" on breakwater dam 1 south section, north side of dam (unvisible from parking lot). Easy to trap the adults here in future (season 2022?).
- ID certain in 2021, both breeders are Caspian Gull cachinnans, y[PHSV] is 11CY and unringed adult partner.
| location | May 15th, 2021. | May 13th, 2021. | . |
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| eggs | April 24th, 2021. | May 13th, 2021: hatching chicks. | May 15th, 2021. |
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| partner 1 | April 26th, 2021: partner y[PHSV]. | April 26th, 2021: partner y[PHSV]. | May 13th, 2021: partner y[PHSV]. |
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| May 13th, 2021: partner y[PHSV]. | April 26th, 2021: partner y[PHSV]. | . | |
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| partner 2 | April 26th, 2021: unringed partner. | April 26th, 2021: unringed partner. | April 26th, 2021: unringed partner. |
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| May 13th, 2021: unringed partner. | May 13th, 2021: unringed partner. | May 28th, 2021: partner with fishline. | |
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| pulli | May 28th, 2021: cachinnans pullus b[F|X]. | May 28th, 2021: cachinnans pullus b[F|Y]. | May 28th, 2021: cachinnans pullus b[F|Z]. |
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Visits and data.
| date: | ||||||
| 24-04-2021 | 2 partners present, one is y[PHSV] and unringed adult. Nest allows trapping breeders, easily. 3 eggs in nest. | |||||
| egg no: | width (mm) | length (mm) | volume (cm3): | water test on April 24th: | ||
| A egg | 49,4 | 75,7 | 93,01 | 45 - tip bottom | ||
| B egg | 50,6 | 76,6 | 98,75 | 45 - tip bottom | ||
| C egg | 51,6 | 73,7 | 98,80 | 65 - tip bottom | ||
| sum nest: | 290,56 | |||||
| 26-04-2021 | Both partners present. Partner 2 with small black spot on primary coverts. | |||||
| 13-05-2021 | Both partners present. | |||||
| 1 chcick: 1,5 days old. | ||||||
| 1 chick: hatching | ||||||
| 1 egg: still in tact. | ||||||
| 15-05-2021 | 1 chick: mass = 88 gr. | |||||
| 1 chick: mass = 107 gr. | ||||||
| 1 egg just hatching. | ||||||
| 28-05-2021 | metal | tibia | mass | head + bill | ||
| pull | .5559409 | b-F|X | >400 | 85 | ||
| pull | .5559410 | b-F|Y | >400 | 88,5 | ||
| pull | .5559411 | b-F|Z | >400 | 78,3 | ||
| Partner 2 has fishgear in beak. | ||||||
| 08-06-2021 | 2 partners at nest. partner 2 has no longer hooked with fishline. | |||||
| 26-06-2021 | No activity. | |||||