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 055
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 055 positioned high on artificial breakwater dam 2, nest between large blocks (labeled "nest with yellow jerrycan", neighbour of nest 54 ny-MT).
Nest marked with yellow jerrycan rom flotsam and jetsam nearby nest. - ID in 2021 certain: all the time only one partner present, which is female Caspian Gull.
- ID in 2022 certain: both parents are Caspian Gull.
- ID in 2023 certain: both parents are same Caspian Gulls as in 2022.
- ID in 2024 certain: both parents are same Caspian Gulls.
| location | April 12th, 2022: y[XCHP] on boulder of nest 55. | April 27th, 2022: nest y[XCHP] and nest 55. | Nest between blocks April 24, 2021 (with Albert de Jong). |
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| location | Eggs April 24th, 2021: 2 eggs clutch. | April 15th, 2022: 3 eggs. | April 26th, 2023: 3 eggs. |
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| partner 1 | April 24th, 2021: partner 1 = female cachinnans. | April 24th, 2021: partner 1 = female cachinnans. | April 24th, 2021: partner 1 = female cachinnans. |
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| partner 1 | April 29th, 2022: female cachinnans. | April 29th, 2022: female cachinnans (different). | May 4th, 2022: female cachinnans. |
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| partner 1 | May 4th, 2022: female cachinnans. | May 11th, 2023: female cachinnans. | May 11th, 2023: female cachinnans. |
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| April 23 2024: female cachinnans. | April 23 2024: female cachinnans. | April 23 2024: female cachinnans. | |
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| partner 2 | April 29th, 2022: male is huge cachinnans. | May 4th, 2022: male cachinnans. | May 4th, 2022: male cachinnans. |
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| partner 2 | May 11th, 2023: male cachinnans. | May 11th, 2023: male cachinnans. | . |
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| partner 2 | April 23 2024: male is same as 2023. | April 23 2024: male cachinnans. | April 23 2024: male cachinnans. |
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| pullus | May 9th, 2022: 1x wet chick. | May 30th, 2022: pullus r[6.S]. | June 21st, 2022: r[6.S] & unringed juvenile. |
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| pullus | June 18th, 2023: pullus r[8.H]. | May 11th, 2023: pullus r[8.W]. | . |
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| pullus | June 18 2024: pullus g-B|U. | May 31 2024: pullus g-M|A. | . |
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Visits and data.
| date: | |||||||
| 16-4-2021 | Nest is empty. | ||||||
| egg no: | width (mm): | length (mm): | volume (cm3): | water test on April 24th: | laying date: | ||
| 24-4-2021 | A | 48,1 | 71,5 | 83,29 | 45 - tip bottom | ||
| 24-4-2021 | B | 49,4 | 68,6 | 84,29 | 25 - tip bottom | ||
| sum nest: | 167,58 | ||||||
| 26-4-2021 | Female Caspian Gull present. | ||||||
| 06-5-2021 | Female Caspian Gull present. A-egg with scratches on one side. | ||||||
| 13-5-2021 | Female Caspian Gull present. Which is the partner??? | ||||||
| 15-5-2021 | 1 egg warm. | ||||||
| 15-5-2021 | 1 egg damaged next to nest. | ||||||
| 28-5-2021 | 1 egg rotten, nesting attempt for 2021 failed? | ||||||
| 26-6-2021 | 1 egg, 2nd brood is a new attempt. | ||||||
Visits and data 2022 for nest 136:
Estimation egg laying: A-egg = April 10 2022. Estimating hatching = May 8 2022.
| date: | |||||||
| 11-04-2022 | XCHP and partner Caspian Gull near nest. In retrospect: XCHP created a nest just below 55, nest 55 appeared to be for 2 other Caspians. | ||||||
| 12-04-2022 | XCHP & partner below 55, on blocks (and that will be nest 221/XCHP for season 2022). Nest 55 for another pair, on top of dam with jerrycan. | ||||||
| Partners are cachinnans. Wing pattern of male and female very similar! Often on top of dam on largest boulders. | |||||||
| egg no: | width (mm): | length (mm): | volume (cm3): | water test April 15th: | |||
| 15-04-2022 | A-egg | 50 | 72,3 | -- | 60 - tip bottom | 3 eggs | |
| B-egg | 50 | 70,8 | -- | 30 - tip bottom | |||
| C-egg | 48,5 | 66,4 | -- | 10 - tip bottom | |||
| sum nest: | -- | ||||||
| 15-04-2022 | Male and female Caspian Gull at nest. Often using large boulders on top of dam as lookout. | ||||||
| Nest 55 is with the orange jerrycan, on top of dam. | |||||||
| Nest 55 is original nest 55-2022, XCHP breeding 8 mtr away, further down on south side of dam 2. | |||||||
| 29-04-2022 | 2 adult Caspian Gulls near nest. | ||||||
| egg no: | width (mm): | length (mm): | volume (cm3): | water test April 15th: | |||
| 29-04-2022 | A-egg | -- | -- | -- | 4 mm - floating | 3 eggs | |
| B-egg | -- | -- | -- | 3 mm - floating | |||
| C-egg | -- | -- | -- | 4 mm - floating | |||
| 04-05-2022 | Male and female Caspian Gull at nest. Large boulders on top of dam are lookout. Female breeding. | ||||||
| Check pattern on innerweb (subterminal band) on P9 for differences between sexes, otherwise birds much alike. | |||||||
| 09-05-2022 | B-egg hatched this moring. 1x egg with small hole, 1x egg with scratches and fractions. | ||||||
| 17-05-2022 | Empty nest. Chicks hiding under boulders, not found. | ||||||
| 22-05-2022 | Empty nest. Chicks hiding under boulders, not found. | ||||||
| metal | darvic | mass | wing | Head+Bill | Bill | ||
| 30-05-2022 | .5625168 | r-6.S | 817 | 175 | 100,3 | 40,3 | |
| 02-06-2022 | 2 adult Caspian Gulls near nest on lookout posts. | ||||||
| 17-06-2022 | 2 adult Caspian Gulls near nest on lookout posts. | ||||||
| 2 chicks present, no view on the legs to check for rings. | |||||||
| 21-06-2022 | 2 chicks present: one is r-6S, and one is unringed. Also 2x adults present. | ||||||
| 28-06-2022 | 2 chicks present: one is r-6S, and one is unringed. Also 2x adults present. Two fledged chicks from nest 55 in 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 | 55-2023 | 68,6 | 50,6 | 88,44 | 68,1 | 51,6 | 91,29 | 65,1 | 48,8 | 78,06 | 257,79 | same as 2022 |
| ring pulli: 12-mei | laying A egg: 7-apr | hatch A egg: 5-mei | ||||||||||
| catch: | date: | metal: | darvic: | mass: | wing: | head+bill: | ||||||
| Pullus | 11-05-2023 | NLA 5556466 | r 8.W | -- | -- | -- | ||||||
| Pullus | 11-05-2023 | NLA 5556467 | r 8.H | -- | -- | -- | ||||||
| Pullus | 27-05-2023 | NLA 5556466 | r-8.W | -- | -- | -- | dead, 2 days ago. | |||||
| Pullus | 27-05-2023 | NLA 5556467 | r 8.H | 758 | -- | -- | not full of energy. | |||||
| Pullus | 18-06-2023 | NLA 5556467 | r-8.H | 586 | 268 | 108,6 | Looks very slim. | |||||
| 55-2023 | ||
| dam: | dam 2 east | |
| location: | next to large boulder which is lookout post, on top of dam, close to yXCHP & yzMT | |
| breeders: | cach x cach | |
| OBSERVATIONS: | ||
| 04-04-2023 | adult: | 2 adult cach on lookout stone. |
| 09-04-2023 | adult: | 2 adult cach on lookout stone. |
| nest: | 2 eggs measured. No watertest, ring chicks in 1st session. | |
| 26-04-2023 | nest: | 3 eggs, all measured. |
| 27-04-2023 | nest: | 3 eggs. |
| adult: | 2 adults present. | |
| 11-05-2023 | pulli: | 2 chicks ringed, is there a 3rd chick? |
| 13-05-2023 | adult: | female & male photographed, exactly same as in 2022. |
| 18-05-2023 | nest: | nest empyt, no chicks found |
| 27-05-2023 | pulli: | 1x dead chick is r-8.W, 2 days ago; 1x chick measured, a bit down, low in energy. |
| 18-06-2023 | pulli: | r-8H present, looks very slim and not healthy. Fledging rate: 1 chick. |
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 | 71 | 51 | 92,98 | 70,9 | 51,1 | 93,22 | 69,7 | 51,5 | 93,08 | 279,28 | ||
| 055-2024 | # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | ||||||
| 3 | 10-4-2024 | 8-5-2024 | |||||||||||
| dam: | dam 2 east | ||||||||||||
| location: | next to large boulder which is lookout post, on top of dam, close to yXCHP. | ||||||||||||
| parents? | same as 2022, 2023 | ||||||||||||
| ring pulli: | 12-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale |
| 14-05-2024 | g-B|U | .5631172 | nest 55 | PONT | 1CY | 235 | |||||||
| 31-05-2024 | g-M|A | .5631135 | nest 55 | PONT | 1CY | ||||||||
| OBSERVATIONS: | |||||||||||||
| 12-04-2024 | eggs: | 2 eggs, measured. | |||||||||||
| adults: | Caspian Gulls present. | ||||||||||||
| 21-04-2024 | eggs: | 3 eggs, measured. | |||||||||||
| 14-05-2024 | chicks: | 1x ringed and measured. | |||||||||||
| 31-05-2024 | chicks: | 1x ringed. | |||||||||||
| 04-06-2024 | adult: | 2x parents present at blocks. | |||||||||||
| 18-06-2024 | chicks: | g-B|U at water. | |||||||||||