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

Home

Cachinnans - nest Lelystad y-P:U60 (068)

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 068 positioned at breakwater 1, centre of large blocks east of T split. Parents has look-out with loads of shit.
  • ID certain in 2021, both are Caspian Gull cachinnans, female is 4CY Caspian Gull y[P:U60], male is large bird.
  • ID certain in 2022, same Caspian Gull cachinnans, female is 5CY Caspian Gull y[P:U60], male is large bird.
  • ID certain in 2023, same Caspian Gull cachinnans, female is 6CY Caspian Gull y[P:U60], male is large bird.
location March 24 2021: 2 partners at dam 1. March 30 2021: 2 partners at Almere waste dump
(17 km's distance from colony).
April 19 2022: partner 2.
 
  June 18th, 2023: 2 partners and 3 large chicks. June 25th, 2023: 2 partners and 3 large chicks. April 27 2022: egg floating.
 
nest April 15 2022: 3 eggs. April 27 2022: 3 eggs. April 09 2023: 3 eggs.
 
partner 1 March 24 2021: y-P:U60 female cachinnans. May 15 2021: y-P:U60 female cachinnans. June 08 2021: y-P:U60 female cachinnans.
 
  April 27 2022: y-P:U60 female cachinnans. May 27 2022: y-P:U60 female cachinnans. April 05 2023: y-P:U60 female cachinnans & partner.
 
partner 2 April 27 2022: male cachinnans. May 30 2022: male cachinnans. May 30 2022: male cachinnans.
 
pullus June 21 2022: chick cachinnans r-5.R. June 21 2022: chick cachinnans r-5.S. June 21 2022: chick cachinnans r-5.T.
 
pullus cachinnans chick r-8.3 fledged 2023. cachinnans chick r-8.5 fledged 2023. cachinnans chick g-7|C fledged 2023.
 
prey May 17 2022: Roach / Rudd. May 17 2022: Perch. .
   

Visits and data.

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 nest y-PU60:
Estimation egg laying: A-egg = April 09 2022. Estimating hatching = May 07 2022.
.

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.