Larus cachinnans in the Netherlands
(last update: August 16, 2020)
Coordinators:
Albert de Jong
Leon Kelder
Roland-Jan Buijs
Thijs Horst
Merijn Loeve
Mars Muusse
Cachinnans - nest Lelystad y-P:AM0 & g-A|E
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 2024: PAM0 positioned at breakwater 1, east of T split, east of the bend. nedst at large blocks in vegetation. Parents have look-out with loads of shit.
- Nest 2025: PAM0 moved to dam 2 west, near lighthouse. New nest, 2 meters W of nest g-A|C (orange football).
- ID certain in 2024: female Caspian Gull cachinnans & male is 5CY Caspian Gull y[P:AM0]. Female trapped in April 2024, now g-A|E.
- ID certain in 2025: male is 5CY Caspian Gull y[P:AM0]. Female ringed in 2025, now g-M|3.
| nest | April 12th, 2024: 2 eggs in cluster. | April 21st, 2024: 3 eggs (full clutch). | April 21st, 2025: 2 eggs (is max for 2025). |
 |
 |
 |
|
| nest | April 21st, 2025: 2 eggs (is max for 2025). | April 23rd, 2025: P:AM0 & partner (future g-M|3). | April 4th, 2025: unringed partner and y-P:AM0. |
 |
 |
 |
|
| partner 1 | March 8th, 2024: y[P:AM0]. | March 19th, 2024: y[P:AM0] & unringed partner. | March 19th, 2024: y[P:AM0]. |
 |
 |
 |
|
| partner 2 | March 19th, 2024: y-P:AM0 & unringed partner. | March 31st, 2024: unringed partner. | April 26 2024: unringed partner now g-A|E. |
 |
 |
 |
|
| partner 2 | April 23rd, 2025: unringed partner now g-M|3. | April 23rd, 2025: unringed partner now g-M|3. | April 23rd, 2025: unringed partner now g-M|3. |
 |
 |
 |
|
| chicks | May 31 2024: chick g-C|Z. | May 31 2024: chick g-C|0. | May 31 2024: chick g-C|1. |
 |
 |
 |
|
| chicks | July 09 2025: chick g-R|D. Fledged. | July 11 2025: chick g-R|E. Fledged. | . |
 |
 |
Visits and data P:AM0 & g-A|E (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: | |
| P:AM0 & g-A|E | cach | cach | 73,6 | 49 | 88,98 | 70 | 50,3 | 89,17 | 68,5 | 48,5 | 81,13 | 259,28 | |
| 2024 | # eggs | A-egg | hatch | # ringed chicks | # all chicks | # fledged chicks | comments | ||||||
| 3 | 10-4-2024 | 6-5-2024 | |||||||||||
| dam: | dam 1 west | ||||||||||||
| location: | Is nest 63-2021/2023. The west nest in the complex. | ||||||||||||
| parents? | y-P:AM0 is new breeder. | ||||||||||||
| ring pulli: | 11-May | ||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | 26-04-2024 | g-A|E | .5625294 | nest PAM0 | PONT | F | >4CY | 443 | 1075 | 126,3 | 53,0 | 66,7 | 18,1 | 5 |
| 31-05-2024 | g-C|Z | .5631125 | y-P:AM0 g-A|E | PONT | 1CY | ||||||||
| 31-05-2024 | g-C|0 | .5631126 | y-P:AM0 g-A|E | PONT | 1CY | ||||||||
| 31-05-2024 | g-C|1 | .5631127 | y-P:AM0 g-A|E | PONT | 1CY | ||||||||
| 04-06-2024 | g-C|Z | .5631125 | y-P:AM0 g-A|E | PONT | 1CY | 220 | 809 | 105,7 | |||||
| OBSERVATIONS: | |||||||||||||
| 08-03-2024 | adult: | y-PAM0. | |||||||||||
| 31-03-2024 | adults: | both parents present. | |||||||||||
| 12-04-2024 | eggs: | 1 egg, measured. | |||||||||||
| 21-04-2024 | eggs: | 3, measured. | |||||||||||
| nest: | cluster again: 60, 69, PAM0, n-F|+, and 2 Herrings to follow soon. | ||||||||||||
| 26-04-2024 | adult: | adult female trapped at nest, now g-A|E. | |||||||||||
| food: | Perch vomit when adult trapped. | ||||||||||||
| 02-05-2024 | eggs: | 3 eggs. | |||||||||||
| 05-05-2024 | nest: | 3 eggs, not measured. | |||||||||||
| 31-05-2024 | chicks: | 3x ringed. | |||||||||||
| 04-06-2024 | chick: | g-C|Z present. measured. | |||||||||||
| 18-06-2024 | chicks: | g-C|0 & g-C|1 dead. | |||||||||||
| chick: | CONTROLL: g-C|Z. | ||||||||||||
Data for nest P:AM0 & M|3 (2025):
| 2025 | parent 1 | parent 2 | A_length | A_width | A_volume | B_length | B_width | B_volume | C_length | C_width | C_volume | TOTAL NEST:
|
# eggs | |
| P:AM0 & M|3 | cach | cach | 70,6 | 51,5 | 68,1 | 50,1 | 2 | |||||||
| dam: | dam 2, next to lighthouse
|
|||||||||||||
| location: | New nest, 2 m W of g-A|C (orange football),
|
|||||||||||||
| ouders: | ||||||||||||||
| ring pulli: | ||||||||||||||
| date | darvic | metal | location / nest# | species | sexe | age | wing | mass | head+ bill | bill | tarsus | gonys | greyscale | |
| 23-4-2025 | g-M|3 | 5641004 | Nest PAM0 | cach | F | >4CY | 421 | 929 | 122,8 | 53,2 | 65,4 | 16,8 | 6 | |
| 31-5-2025 | g-R|D | 5641895 | y-P:AM0 & g-M|3 | PONT | pullus | 426 | ||||||||
| 31-5-2025 | g-R|E | 5641896 | y-P:AM0 & g-M|3 | PONT | pullus | 465 | ||||||||
OBSERVATIONS:
|
||||||||||||||
| 3/16/2025 | nest | PAM0 not present, female g-A|E present, slightly more to the west on dam 1,
|
||||||||||||
| 3/21/2025 | feeding | PAM0 on bread near poles dam 2, not seen at nest location, g-A|E not seen that day
|
||||||||||||
| 3/25/2025 | feeding | PAM0 present at Almere wastedump
|
||||||||||||
| 4/12/2025 | nest | PAM0 at location nest 203-2020, between Spoonbills,
|
||||||||||||
| 4/21/2025 | nest | 2 eggs, measured,
|
||||||||||||
| 4/23/2025 | nest | 2 eggs, | ||||||||||||
| adult | trapped female, now g-M|3, incubating 2 eggs at nest PAM0,
|
|||||||||||||
| 4/28/2025 | nest | 2 eggs | ||||||||||||
| 1/5/2025 | nest | 2 eggs | ||||||||||||
| 8-5-2025 | adult | y-P:AM0 present
|
||||||||||||
| 13-5-2025 | nest | 1 wet chick, 1 hatching
|
||||||||||||
| 31-5-2025 | nest | 2 chicks ringed
|
||||||||||||