Larus cachinnans in the Netherlands

(last update: August 16, 2020)

Coordinator:
Albert de Jong
Merijn Loeve
Roland-Jan Buijs
Thijs Horst
Leon Kelder
Mars Muusse

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Caspian Gull cachinnans P:U60 4CY-8CY, March 2021 - March 2025, Lelystad & Almere, the Netherlands. Picture: Thijs Horst, Mars Muusse & Albert de Jong.

Metal ring PLG DN35458 and yellow P:U60, ringed as pullus on June 09 2018 in a mixed Caspian Gull colony "Larus cachinnans kolonia" with cachinnans dominance, at river Wisla, POLAND, by ringer Lukasz Bednarz.
In all respects, y[P:U60] is cachinnans, no indication for hybrid. Breeding in nest y[P:U60].

From 2021 onwards, breeding in colony Lelystad, nest always at the same spot (2021-2024).
09/06/2018 Rz.Wisła,Zastów Karczmiski,Opole Lubelskie POLAND (LUBELSKIE) Łukasz Bednarz
03/08/2018 Składowisko odpadów PUO Świdnica, Sulisławice POLAND (DOLNOŚLĄSKIE) Benedykt Adamczyk
09/09/2018 Dreba-Plother-Teichgebiet: Kohlungsteich GERMANY (THÜRINGEN) HIDDENSEE .DEH Schoder, Frank
17/04/2020 Salzgitter-Heerte:Deponie GERMANY (NIEDERSACHSEN: BRAUNSCHWEIG) Gerhard Braemer
16/05/2020 Orava lake, Bird island SLOVAKIA (NAMESTOVO) Miro Demko
19/03/2021 Almere: de Vaart NETHERLANDS (FLEVOLAND) Eric Roeland
23/03/2021 Almere: de Vaart NETHERLANDS (FLEVOLAND) Eric Roeland
24/03/2021 Lelystad NETHERLANDS (FLEVOLAND) Mars Muusse Albert de Jong
04/05/2021 Almere de Vaart NETHERLANDS (FLEVOLAND) thijs horst
04/08/2021 Trintelzand NETHERLANDS (FLEVOLAND) D. B.
09/10/2021 Almere: de Vaart NETHERLANDS (FLEVOLAND) Eric Roeland
21/06/2022 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst
19/09/2022 dike Enkhuizen-Lelystad NETHERLANDS (FLEVOLAND) Guus van Duin
05/02/2023 Almere: de Vaart NETHERLANDS (FLEVOLAND) Eric Roeland
13/02/2023 Almere de Vaart NETHERLANDS (FLEVOLAND) thijs horst
24/02/2023 Almere: de Vaart NETHERLANDS (FLEVOLAND) Eric Roeland
26/03/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
04/04/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
06/04/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse Albert de Jong
09/04/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
13/05/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
27/05/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse Merijn Loeve
18/06/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
25/06/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst
08/07/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
18/07/2023 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
15/12/2023 Almere: de Vaart NETHERLANDS (FLEVOLAND) Eric Roeland
16/01/2024 Almere de Vaart NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
18/01/2024 Almere de Vaart NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
19/03/2024 Lelystad, Bataviahaven NETHERLANDS (FLEVOLAND) Maarten Hotting
19/03/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
20/03/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
25/03/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst
26/03/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
30/03/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Harry Kuipers
30/03/2024 Lelystad, Bataviahaven NETHERLANDS (FLEVOLAND) Harry Kuipers
31/03/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
08/04/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse Gabi Martin, Theo Muusse
11/04/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) J. de L.
21/04/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
23/04/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
26/04/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse Albert de Jong
02/05/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse, Albert de Jong
05/05/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse, Fred Cottaar
07/05/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
17/05/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst
31/05/2024 Lelystad Colony Oostvaardersdiep NETHERLANDS (FLEVOLAND) Merijn Loeve Thijs Horst
04/06/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse Albert de Jong
18/06/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
24/06/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst
25/06/2024 Bataviahaven, Lelystad NETHERLANDS (FLEVOLAND) thijs horst Mars Muusse
30/07/2024 De Kreupel NETHERLANDS (FLEVOLAND) thijs horst Jeroen van Assema

In 2021 breeding bird at colony Lelystad, the Netherlands. Y-P:U60 is a female, partner is large unringed adult male Caspian Gull cachinnans in nest 68.
This nest is in a section with large bolders and blocks, nest not visible from the water and many Lesser Black-backed Gulls breeding around and nests at close range.
Chicks can hide in numerous crevices underneath the blocks, making them hard to find. Visits and data for this nest in 2021:
date: egg no: width (mm) length (mm) volume (cm3):  water test on May 7th:  
06-05-2021 A 50,1 73,3 91,34 90 - tip at bottom. 2 eggs in the nest, one partner is y[P:u60] 4CY cachinnans.
  B 49,2 70,9 92,28 90 - floating halfway.  
      sum nest: --    
13-05-2021 No visit, Camilla is trapping a spoonbill.
15-05-2021 2 eggs, still complete. y[P:U60] and partner is large Caspian Gull male.
28-05-2021 nest is empty. y[P:U60] and partner both alarming. Chicks not found between all those blocks.
08-06-2021 No activity visible from south side. Later, from north side y[P:U60] flying around.
   

Data for 2022 nest y-PU60:
Estimation egg laying: A-egg = April 09 2022. Estimating hatching = May 07 2022. Nest is at exactly same location as previous year.
.

12-04-2022 y-P:U60 present. Nest not excatly located yet, but close to place of previous season.
  egg no: width (mm) length (mm) volume (cm3):  water test on April 12th:  
15-04-2022 A 51,8 72,9 -- 40 - tip at bottom. 3 eggs in the nest.
  B 51,3 71,6 -- 30 - tip at bottom. Extrapolation: 1st egg laid on April 9th; 1st egg will hatch on May 7th. Ring: May 14th.
  C 50,1 70,5 -- 20 - tip at bottom.  
      sum nest: --    
27-04-2022 A       4 mm- floating. 3 eggs in the nest.
  B       3 mm- floating.  
  C       2 mm- floating.  
09-05-2022 y-P:U60 present.
  metal darvic mass  
17-05-2022 .5625114 r-5T 293 Much fish around nest, incl Roach / Rudd and Perch.
  .5625115 r-5S 191      
  .5625116 r-5R 329      
  metal darvic mass  
30-05-2022 .5625116 r-5R 680 y-P:U60 and partner are present, together with (at least) .
02-06-2022 2 adults and 3 large chicks present.
17-06-2022 2 adults and (at least) 2 chicks present.
21-06-2022 2 adults and all 3 large chicks r-5R, r-5S & r-5T present.
28-06-2022 2 adults and all 3 large chicks r-5R, r-5S & r-5T present.
 
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 PU60 76,6 51 100,32 69,2 50,3 88,15 72,1 51,3 95,54 284,01 same as 2022
ring pulli: 10-mei laying A egg: 5-apr hatch A egg: 3-mei
     
date: metal: darvic: mass: wing: head+bill:      
pullus 11-05-2023 NLA5556478 r 8.3 -- -- --
pullus 11-05-2023 NLA5556479 r 8.5 -- -- --
pullus 18-05-2023 5556495 G-7|C 550 -- 89,8
pullus 27-05-2023 5556495 G-7|C 955 -- --
   
dam: dam 1 blocks
location: location is PU60-2022. Red spot on block near nest.
breeders: cach x cach
OBSERVATIONS:
09-04-2023 adult: female PU60 & adult male cach present. Red spot renewed.
nest:  3 eggs measured. Watertest C-egg: 20 - tip bottom.
11-05-2023 pulli: 2 chicks ringed, is there a 3rd chick?
13-05-2023 adult: PU60 & male cach present.
18-05-2023 pulli: 1 chick ringed G-7|C, R-85 present.
27-05-2023 pulli: 1x control chick G-7|C.
18-06-2023 pulli: r-83, r-85, g7|C present, with 2 adults (incl PU60). Fledged: 3 juveniles.
25-06-2023 pulli: family complete, 3x chicks 2x parents. Result 2023: 3x fledged juveniles.

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:
P:U60 2024 cach cach 75 52,6 104,48 74,6 51,7 100,40 72 50,7 93,19 298,06
  # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 10-4-2024 6-5-2024
   
dam: dam 1 blocks
location: location is PU60-2022/2023. Red spot + P on block near nest.
parents? same as 2023
   
ring pulli: 11-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
14-05-2024 g-B|8 .5631193 nest PU60 PONT 1CY 282          
14-05-2024 g-B|9 .5631194 nest PU60 PONT 1CY          
04-06-2024 g-B|8 .5631193 nest PU60 PONT 1CY 260 839 108,7        
04-06-2024 g-B|9 .5631194 nest PU60 PONT 1CY 179 514 95,7        
                           
OBSERVATIONS:
12-04-2024 eggs: 2 eggs, measured.
21-04-2024 eggs: 3 eggs, measured
  adult: both parents present. PU60 (incubating) & unringed male (guarding).
23-04-2024 adult: both parents present.
07-05-2024 eggs: 2 eggs hatching, 1 chick just out, not ringed.
14-05-2024 chicks: 2x ringed, 3rd chick not found.
31-05-2024 chicks: g-B|8, g-A|9 present.
04-06-2024 chicks: g-B|8 & g-B|9 present. measured.
18-06-2024 chicks: g-B|8 present.

below: Caspian Gull cachinnans P:U60 8CY, March 21 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans P:U60 8CY, March 16 2025, colony Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.

Back at same location as nest in 2024. And, just for no good reason, finally reacting to bread, for only 2 seconds.

below: Caspian Gull cachinnans P:U60 7CY, July 30 2024, colony De Kreupel, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans P:U60 7CY, June 25 2024, colony Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.

Together with the only fledged chick for 2024: g-B|8.

below: Caspian Gull cachinnans P:U60 6CY, July 18 2023, Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.

below: Caspian Gull cachinnans P:U60 6CY, July 08 2023, Lelystad, the Netherlands. Picture: Thijs Horst & Mars Muusse.

below: Caspian Gull cachinnans P:U60 6CY, April 05 2023, Lelystad, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans P:U60 6CY, February 13 2023, Almere, the Netherlands. Picture: Thijs Horst & Mars Muusse.

With male partner at Almere dump.

below: Caspian Gull cachinnans P:U60 5CY, June 21 2022, Lelystad, the Netherlands. Picture: Thijs Horst.

below: Caspian Gull cachinnans P:U60 5CY, May 30 2022, Lelystad, the Netherlands. Picture: Mars Muusse.

below: Caspian Gull cachinnans P:U60 5CY, April 27 2022, Lelystad, the Netherlands. Picture: Mars Muusse.

below: Caspian Gull cachinnans P:U60 4CY, June 08 2021, Lelystad, the Netherlands. Picture: Mars Muusse & Albert de Jong.

below: Caspian Gull cachinnans P:U60 4CY, May 15 2021, Lelystad, the Netherlands. Picture: Mars Muusse & Mónika Ballmann.

below: Caspian Gull cachinnans P:U60 4CY, March 30 2021, Almere, the Netherlands. Picture: Mars Muusse.

Y-P:U60 and her partner present at a small local waste dump at Almere, distance about 17 km's from the colony.

below: Caspian Gull cachinnans P:U60 4CY, March 24 2021, Lelystad, the Netherlands. Picture: Mars Muusse & Albert de Jong.

Also present today: w-327:U from Czechia.