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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Cachinnans - nest Lelystad 014

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 014 positioned at breakwater 2. Same spot throughout years 2020-2023.
  • ID certain in 2020, both parents are Caspian Gull cachinnans.
  • ID certain in 2021, both parents are the same as previous year, Caspian Gull cachinnans.
  • ID certain in 2022, both parents are the same as previous year, Caspian Gull cachinnans.
  • ID certain in 2023, both parents are the same as previous year, Caspian Gull cachinnans.
location Nest location on April 15th, 2020. April 16th, 2021. April 26th, 2021: female on block.
 
  April 9th, 2023: location.    
     
eggs April 15th, 2020: 3 egg clutch. April 15th, 2022: 3 egg clutch. April 9th, 2023: first egg.
 
partner 1 April 27th, 2020: cachinnans. . .
   
partner 1 April 16th, 2021. April 16th, 2021: P9 with thin band. April 11th, 2022: male is cachinnans.
 
partner 1 April 12th, 2022: male is cachinnans. April 11th, 2022: male is cachinnans. April 27th, 2022: male is cachinnans.
 
partner 1 April 26 2024: Caspian Gull male. April 26 2024: Caspian Gull male. .
 
partner 2 May 7th, 2020: cachinnans. May 7th, 2020: cachinnans. .
   
partner 2 April 26th, 2021: female cachinnans. April 26th, 2021: P9 with broad band. April 26th, 2021: female cachinnans.
 
partner 2 April 29th, 2022: female cachinnans. April 29th, 2022: female cachinnans. April 29th, 2022: female cachinnans.
 
  April 27th, 2023: female cachinnans. May 13th, 2023: female cachinnans.  
   
partner 2 April 26 2024: Caspian Gull female. April 26 2024: Caspian Gull female. April 26 2024: Caspian Gull female.
 
pullus May 21st, 2020 pullus n[F|=]. May 21st, 2020 pullus n[F|+].  
   
pullus June 8th, 2021: female with chick. June 26th, 2021: pullus r[F.L] .
   
  June 26th, 2021: pullus r[F.M] June 26th, 2021: pullus r[F.N] .
   
pullus May 9th, 2022: pullus r[C.T]. May 9th, 2022: pullus r[C.U]. May 17th, 2022: pullus r[5.2].
 
  May 11th, 2023: pullus r[7.=]. May 11th, 2023: pullus r[8.U]. May 11th, 2023: pullus r[8.X].
 

Visits and data:
Estimation egg laying: A-egg = April 09 2022. Estimating hatching = May 07 2022.

datum: egg no: width (mm) length (mm) volume (cm3):  water test on April 27th:  
15-04-2020 A 50,5 76,9 98,74 35 - tip on bottom 3 eggs in nest.
  B 50,4 77,2 98,74 25 - tip on bottom  
  C 50,4 71,8 91,83 15 - tip on bottom  
  sum nest: 289,31
27-04-2020 Certainty about parents, cachinnans.
   
21-05-2020 pullus Nest empty, with fish. 2 chicks ringed. n[F|=].
  pullus Nest empty, with fish. 2 chicks ringed. n[F|+].
   
02-06-2020 pulli n[F|=] together with large juvenile, so nest with 3 juveniles fledged?
         
date:        
  egg no: width (mm) length (mm) volume (cm3):  water test on April 27th:  
16-04-2021 A egg 52,2 73,9 101,39 40 - tip on bottom 3 eggs.
B egg 51,2 73,7 97,28 40 - tip on bottom  
C egg 50,2 68,7 87,17 30 - tip on bottom  
         
         
26-04-2021 Partner 1 at blocks in front of nest. Seemingly same parents as last year.
         
15-05-2021 3 eggs. (in retrospect: we should have checked for presence of letters on the eggs. Was this the still the same brood as on April 26th?)
         
28-05-2021 2 eggs + 1 chick (1 day old). What has been the breeding period for these eggs??? Was there a rapid 2nd attempt in late April???
  Female at nest, but P10 slightly ackward for pure cachinnans? (probably wrong bird?)
   
08-06-2021 Male is cachinnans.
  Female appears at blocks with one chick.
         
  metal tibia mass head + bill wing  
26-06-2021 .5550684 r-F.L 859 111,7 264 cachinnans
  .5550685 r-F.M 948 112,8 252 cachinnans
  .5550686 r-F.N 912 112,2 228 cachinnans
             
date:        
11-04-2022 adult near nest.
             
  egg no: width (mm) length (mm) volume (cm3):  water test on April 27th:  
15-04-2022 A egg 51,7 70 -- 10 - tip on bottom 3 eggs.
B egg 51,7 76,7 -- 30 - tip on bottom  
C egg 51,7 72,1 -- 20 - tip on bottom  
         
19-04-2022 guarding adult on block.
             
29-04-2022 A egg float - 1 mm      
  B egg float - 2 mm      
  C egg float - 1 mm      
             
  metal tibia mass head + bill wing  
09-05-2022 5625068 r-C.T       cachinnans
  5625069 r-C.U       cachinnans
  1 egg, hatching soon (A-egg).    
             
  metal tibia mass head + bill wing  
17-05-2022 5625069 r-C.U 363 --   cachinnans
  5625136 r-5.2 206 69,7   cachinnans
30-05-2022 from the boat one ringed chick visible, not found back later between blocks.
17-06-2022 two ringed chicks present, possibly 3rd as well, but not seen.
21-06-2022 r-52 swimming, together with r-54 (from nest y-X56A). R-CU & r-CT not seen.
21-06-2022 Later this day: now r-52 swimming in creche with another 3 juveniles, including r-CU. Not all legs visible, to check for rings.
17-07-2022 r-52 photographed.
 
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 14-2023 73,9 50,7 95,64 75,8 51 99,27 68 50,2 86,28 281,19 same as 2022
ring pulli: 14-mei laying A egg: 9-apr hatch A egg: 7-mei
     
catch: date: metal: darvic:      
Pullus 11-05-2023 NLA5556459 r-7.=
Pullus 11-05-2023 NLA5556460 r-8.U
Pullus 11-05-2023 NLA5556461 r-8.X
 
14-2023
dam: dam 2 central
location: "14" code strayed on stone. Is nest 14-2020/2022
breeders: cach x cach
OBSERVATIONS:
09-04-2023 nest: 1 egg measured. No watertest.
26-04-2023 nest: 3 eggs measured, and water test A: floating - 1 mm
adult: alarming parent B: floating - halfway
27-04-2023 adult: Male cach at nest. Female guarding C: floating - 0 mm
11-05-2023 pulli: 3 chicks ringed
13-05-2023 adult: male dark eye, no black P4. Female pale eye, black on P4.
27-05-2023 nest: no alarming adults, no chicks found. Nest failed apparently.

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:
014-2024                    
. # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
       
   
dam: dam 2 central, code on block.
location: all in the open, obvious spot for years
parents? Not settled yet.
   
ring pulli:  
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
                           
OBSERVATIONS:
21-04-2024 eggs: nest empty. Location used by r-6L to rest. Sometimes adult cach present.
26-04-2024 adults: 2x adult Caspian Gull at nest site.
07-05-2024 nest: empty.