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

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Argenteus - nest Lelystad 61Z

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 61Z positioned on dam 1 south section, cluster of nests also containing one cachinnans.
  • Nest included for "Herring Gull control nests".
  • ID uncertain in 2022: one parent is Herring Gull, partner unknown (but most likely also Herring Gull, we did not have another Caspian here, and several Herrings).
  • ID certain in 2023: both parents are Herring Gull argenteus.
location May 1st, 2022: nest location. April 27th, 2022: 3 eggs. .
   
partner 1 May 1st, 2022: partner 1 is argenteus. April 27th, 2022: partner 1 is argenteus. .
 
pullus May 17th, 2022: pullus metal ringed. May 17th, 2022: pullus r[6.G], sibling of r[6.F]. .
   
pullus May 27th, 2023: pullus g[8|+]. May 27th, 2023: pullus g[9|E]. May 27th, 2023: pullus g[9|F] (LBBG chick from neighbour).
 
pullus June 18th, 2024: pullus g-C|W. May 14th, 2024: pullus g-C|X. June 18th, 2024: pullus g-C|Y.
 

Visits and data:
Estimation egg laying: A-egg = April 19 2022. Estimating hatching = May 17 2022.

date:              
15-04-2022 adult near empty nest.  
               
19-04-2022 2 adult Herring gulls present.  
               
  egg no: width (mm): length (mm): volume (cm3):       
27-04-2022 A 48,4 66 -- 35 - tip bottom 3 eggs  
  B 47,6 66,7 -- 80 - tip bottom  
C 48,6 66,9 -- 50 - tip bottom
sum nest: --
   
  egg no:     3 eggs, 1 adult has short white tongue on P10: hybrid?    
29-04-2022 A float - 4 mm          
  B float - 4 mm        
C float - 5 mm    
   
01-05-2022 Herring Gull at nest.
   
04-05-2022 3 eggs.
   
09-05-2022 3 eggs.
   
17-05-2022 2 eggs.
A egg hatching, small hole.
C egg in tact,
B chick ringed, only metal ring.
   
  metal darvic mass H+B wing    
17-05-2022 .5625101 -- -- -- -- (chick just hatched, 1 day old)
           
22-05-2022 .5625101 r-6.G 186 62,6 38
22-05-2022 .5625159 r-6.F 114 57 33 chick near nest 61Z, but very likely (99%) from nest 123. >> see 123Z
22-05-2022 C egg still in nest (infertile). Chick rate: 1 out of 3 eggs.
   
  metal darvic mass H+B wing bill  
30-05-2022 .5625101 r-6.G 490 81 95 32
30-05-2022 .5625159 r-6.F 385 77,8 70 29
   
12-07-2022 picture of r[6.G].
 
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?
teus x teus 61Z 67,3 49 81,36 -- -- -- -- -- -- 81,36 same as 2022
ring pulli: nn laying A egg: nn hatch A egg: nn
 
catch: date: metal: darvic: mass: wing: head+bill:
Pullus 27-5-2023 5.625.280 g-8|+ 210 -- teus in cluster van nesten.
Pullus 27-5-2023 5.625.282 g-9|F 218 -- KMM Observed it with 2 LBBG parents (positive interaction).
Pullus 27-5-2023 5.625.283 g-9|E 230 -- teus in cluster van nesten.
   
61Z-2023 Herring Gulls
dam: dam 1 west
location: Is in front of n[F|N]. Same as 61-2022.
breeders: teus x teus
OBSERVATIONS:
22-04-2023 nest 1 egg.
27-04-2023 adult: 2x Herring Gull partners.
13-05-2023 adult: 2x Herring Gull partners.
27-05-2023 pulli: 2x teus pulli ringed. Later a 3rd (g-9|F) pullus ringed at this very same location, believed to belong to 61 as well. But from boat we observed it with LBBG parents (positive interaction).
     
     
61Z-2024 Herring Gulls
dam: dam 1 west
location: Is in front of n[F|N]. Same as 61-2022 & 61-2023.
breeders: teus x teus
 
age: date: metal: darvic: mass: wing: head+bill:
Pullus 31-05-2024 .5631122 g-C|W       Herring Gulls nest 61Z
Pullus 31-05-2024 .5631123 g-C|X        
Pullus 31-05-2024 .5631124 g-C|Y        
Pullus 04-06-2024 .5631122 g-C|W 461 98 82,3 CONTROLL
Pullus 04-06-2024 .5631123 g-C|X 461 112 83,1 CONTROLL
Pullus 04-06-2024 .5631124 g-C|Y 445 80 83,4 CONTROLL
Pullus 18-06-2024 g-C|W & g-C|Y present at dam.