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 y-PNED
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 002 positioned high on artificial breakwater in reedbed, between some small Elderberry bushes and dense Blackberry vegetation. 2 meters from nest 001.
- ID certain in 2020, breeders are Caspian Gull cachinnans PNED 8CY and unringed adult male partner.
- ID certain in 2021, same breeders are female Caspian Gull cachinnans PNED 9CY and unringed adult partner.
- ID certain in 2022, same breeders are female Caspian Gull cachinnans PNED 10CY and unringed adult partner.
- ID certain in 2023, same breeders are female Caspian Gull cachinnans PNED 11CY and unringed adult partner. This season they breed at location "nest 136-2022".
| location | Nest in vegetation. | April 16th, 2021: nest location. | April 16th, 2021: nest location with Albert. |
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| eggs | Eggs April 27th, 2020: 3 eggs clutch. | Eggs April 27th, 2022: 3 eggs clutch. | Eggs April 26th, 2023: 3 eggs clutch. |
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| partner 1 | May 7th, 2020: y PNED | May 7th, 2020: y PNED | June 2nd, 2020: y PNED |
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| June 2nd, 2020: female y[PNED]. | April 27th, 2022: female y[PNED]. | April 9th, 2023: female y[PNED]. | |
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| partner 2 | May 7th, 2020: unringed male partner | May 7th, 2020: unringed partner | April 27th, 2022: unringed partner |
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| May 7th, 2020: unringed partner | 2021: unringed partner of y-PNED. | 2022, May 4th: unringed partner of y-PNED. | |
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| 2023, April 26th: unringed partner & y-PNED. | 2023, June 18th: unringed partner of y-PNED. | 2023, May 13th: unringed partner of y-PNED. | |
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| pulli | n-F|C 2019 chick; 2022 & 2023 breeding at De Kreupel. | May 21st, 2020 pullus n[F|X]. | June 2nd, 2020 unringed pullus, assumed nest 002. |
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| May 28th, 2021 pullus red-F.F. | May 28th, 2021 pullus red-F.G. | June 14th, 2021: parents + 3 chicks (picture Camilla Dreef). | |
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| June 8th, 2021 juvenile r-F.G. | July 9th, 2021 juvenile r-F.G. | July 9th, 2021 juvenile r-F.G. | |
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| May 17th, 2022: r-C.E dead. | June 21st, 2022: r-C.D fledged. | June 28th, 2022: r-C.D fledged. | |
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| Juvenile g-7|N fledged in 2023. | Juvenile g-7|P fledged in 2023. | June 18th, 2023: unringed 3rd chick also fledged. | |
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Visits and data.
| date: | egg no: | width (mm): | length (mm): | volume (cm3): | water test on April 27th: | ||
| 15-04-2020 | A | 51,8 | 71,3 | 96,33 | 90 - floating, 4mm above surface | ||
| 27-04-2020 | B | 51,3 | 75,5 | 100,04 | 90 - floating, 4mm above surface | ||
| C | 50,5 | 68,1 | 87,44 | 90 - hafway in water | |||
| sum nest: | 283,81 | ||||||
| 21-05-2020 | pullus | Empty nest, 1 chick near nest, ringed Noir F|X | |||||
| date: | |||||||
| 16-04-2021 | y[PNED] present at nest guarding at blocks, nest with 3 eggs. | ||||||
| egg no: | width (mm): | length (mm): | volume (cm3): | water test on April 16th: | |||
| A egg | 52,1 | 77,3 | 105,65 | 35 - tip bottom | |||
| B egg | 52 | 76 | 103,47 | 35 - tip bottom | |||
| C egg | 50,8 | 69,5 | 90,30 | 35 - tip bottom | |||
| sum nest: | 299,42 | ||||||
| 26-04-2021 | PNED present and alarming. Fight with neighbour or partner. | ||||||
| Partner PNED also present. | |||||||
| 06-05-2021 | Picture of partner. | ||||||
| 2 eggs hatching, 1 pullus just emerging. | |||||||
| 15-05-2021 | No visit. | ||||||
| 28-05-2021 | metal | tibia | mass | head + bill | |||
| pull | .5559430 | red-F.F | 908 | 105 | |||
| pull | .5559431 | red-F.G | 673 | 94,8 | |||
| 08-06-2021 | At north side of dam 1: r-F.G and another chick at the blocks (is this maybe r-F.F?). | ||||||
| 14-06-2021 | Picture Camilla Dreef: 2 ringed + 1 unringed chick together with parents at blocks. | ||||||
| 26-06-2021 | No visit. | ||||||
| 09-07-2021 | Picture of r-F.G added, now a handsome juvenile. | ||||||
| Visits and data 2022 for nest PNED: Estimation egg laying: A-egg = April 3 2022. Estimating hatching = May 1 2022. |
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| 11-04-2022 | y[PNED] present at nest. | ||||||
| 12-04-2022 | y[PNED] present at nest. | ||||||
| 15-04-2022 | y[PNED] present at nest. | ||||||
| egg no: | width (mm): | length (mm): | volume (cm3): | water test on April 15th: | |||
| A egg | 50,4 | 71,6 | -- | 70 - tip bottom | |||
| B egg | 51 | 73,4 | -- | 80 - tip bottom | |||
| C egg | 50,5 | 75,8 | -- | 90 - tip bottom | |||
| sum nest: | -- | ||||||
| 19-04-2022 | y[X56A] present at nest for a short while, took off again. | ||||||
| 27-04-2022 | y[PNED] present at nest. Place yellow-black flag. | ||||||
| egg no: | width (mm): | length (mm): | volume (cm3): | water test on April 15th: | |||
| A egg | -- | 2 mm - floating | |||||
| B egg | -- | 4 mm - floating | |||||
| C egg | -- | 3 mm - floating | |||||
| 01-05-2022 | y[PNED] guarding at nest. Partner breeding. | ||||||
| 09-05-2022 | metal | tibia | mass | head + bill | |||
| pull | 5625055 | r-C.D | -- | -- | |||
| pull | 5625056 | r-C.E | -- | -- | |||
| food | r-CE throws up 1 Rounded Goby. | ||||||
| egg | 1 old egg. | ||||||
| 17-05-2022 | r-CE dead, stuck between rocks. | ||||||
| 30-05-2022 | r-CD swimming between dams. Aggressively protected by y-PNED. | ||||||
| 17-06-2022 | r-CD swimming/flying between dams. Aggressively protected by y-PNED. | ||||||
| 21-06-2022 | r-CD swimming/flying between dams. Aggressively protected by y-PNED. | ||||||
| 28-06-2022 | r-CD swimming/flying between dams. Aggressively protected by y-PNED. | ||||||
| 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 | PNED | 73,4 | 52,1 | 100,32 | 73,1 | 50 | 92,01 | 68 | 49,8 | 84,91 | 277,24 | same as 2022 |
| ring pulli: 9-mei | laying A egg: 6-apr | hatch A egg: 4-mei | ||||||||||
| catch: | date: | metal: | darvic: | mass: | wing: | head+bill: | ||||||
| Pullus | 18-05-2023 | 5556405 | G-7|N | 635 | -- | 95 | ||||||
| Pullus | 18-05-2023 | 5556406 | G-7|P | 616 | -- | 92,3 | ||||||
| Pullus | 27-05-2023 | 5556405 | G-7|N | 1030 | -- | -- | ||||||
| PNED | nest 136-2022 | ||||
| dam: | dam 1 east | ||||
| location: | Visible from N. | ||||
| breeders: | cach x cach | ||||
| OBSERVATIONS: | |||||
| 09-04-2023 | adult: | male unringed cach & female cach yPNED present at location. So search for nest today. | |||
| 26-04-2023 | adult: | male unringed cach & female cach yPNED present at location. | |||
| nest: | code 136, birds have moved to this location. "136" sprayed on block + blue foam. | ||||
| eggs: | 3x eggs, measured. | A | 1 mm - float | ||
| B | 1 mm - float | ||||
| C | 1 mm - float | ||||
| 13-05-2023 | adult: | cach male. | |||
| 18-05-2023 | pulli: | 2 chicks ringed, 3rd not found. | |||
| 27-05-2023 | pulli: | 1 chick measured. | |||
| 18-06-2023 | pulli: | g-7|P & g-7|N present + unringed sibling. 3x fledged from PNED. | |||
| adult: | y-PNED present. Unringed male guarding g-7|P. | ||||
| 25-06-2023 | pulli: | g-7|N alone, g-7|P with unringed sibling. | |||