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 021

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 021 positioned at breakwater 1 at T-split corner near Spoonbills. In 2021 position of nest is exactly the same, marked with "the grey jerrycan" from flotsam. Nest close to Spoonbill nests, therefore limited visits. Instead: observed from distance with binoculars or telescope.
  • ID in 2020 certain, Caspian Gull cachinnans; one partner with sub-adult patterns.
  • ID in 2021: 2 partners are adult Caspian gull cachinnans. Ringed chicks 2021 quickly after fledging reported from abroad (click links on pulli thumbnails below).
  • ID in 2022 uncertain. One parent is Caspian Gull, other parent not photgraphed. Location is exactly the same as in 2021 & 2020.
  • ID in 2023 certain: both parents are Caspian Gull. Male same as in 2022 (P8 mirror left wing). Location is exactly the same as 21-2020 / 2022.
  • ID in 2024 certain: both parents are Caspian Gull. Male same as in 2022 (P8 mirror left wing). Location is exactly the same as 21-2020 / 2023.

below: Caspian Gull cachinnans adult, April 27 2020, Lelystad, the Netherlands. Picture: Albert de Jong.

Albatrossing to the partner flying overhead. On the right: adult Lesser Black-backed Gull breeder on nest 22, and some Spoonbills in the background.

location April 27th, 2020: nest location. May 7th, 2020: nest location. April 27th, 2020: 3 eggs clutch.
 
location April 16th, 2021: 2 eggs clutch. April 27th, 2022: 3 eggs clutch. April 27th, 2022: 3 eggs clutch.
 
location April 9th, 2023: 1 egg. April 26th, 2023: 3 eggs clutch. April 26th, 2023: nest location.
 
  April 21st, 2024: 3 eggs clutch. . .
     
partner 1 May 7th, 2020: male cachinnans 4CY? May 7th, 2020: male cachinnans 4CY? May 7th, 2020: male cachinnans 4CY?
 
partner 1 April 16th, 2021: male cachinnans. April 16th, 2021: male cachinnans. May 9th, 2022: male cachinnans.
 
partner 1 May 9th, 2022: male cachinnans. May 9th, 2022: male cachinnans. July 8th, 2023: male cachinnans. P8 mirror in left wing.
 
partner 1 May 14 2024: male Caspian Gull. May 14 2024: male Caspian Gull. May 14 2024: male Caspian Gull.
 
partner 2 May 7th, 2020: female cachinnans. May 7th, 2020: female cachinnans. May 13th, 2023: female cachinnans.
 
partner 2 May 13th, 2023: female cachinnans. May 14th, 2024: female cachinnans. May 14th, 2024: female cachinnans.
 
pulli May 21st, 2020: pullus n[F|2]. May 21st, 2020: pullus n[F|4]. May 17th, 2022: pullus r[5.J].
 
pulli May 17th, 2022: pullus r[5.K]. July 8th, 2023: r[8.D]. July 18th, 2023: r[8.E].
 
pulli May 11th, 2023: pullus r[8.Y]. May 14 2024: pullus g-B|+. May 14 2024: pullus g-B|=.
 

Visits and data 2022:
Estimation egg laying: A-egg = April 13 2022. Estimating hatching = May 11 2022.

date:            
  egg no: width (mm) length (mm) volume (cm3):  water test on April 15th:  
27-04-2020 A 49,6 68,9 85,35 30 - angled, tip on bottom 3 eggs in the nest. Male with sub-adult pattern.
27-04-2020 B 49,8 70 87,41 60 - angled, tip on bottom  
27-04-2020 C 50,1 66,6 84,17 35 - angled, tip on bottom
  sum nest: 256,92
21-05-2020 pulli     Two chicks, ringed n[F|2] & n[F|4]. C-egg is unfertile, taken from nest.
         
02-06-2020 pulli     Two partners at nest.
         
date 2021:        
             
16-04-2021 egg no: width (mm) length (mm) volume (cm3):  water test on April 16th:  
  A 50,5 70,9 91,04 20 - flat on bottom 2 eggs in the nest and 1 adult. Eggs just laid.
  B 49,5 74,5 91,91 15 - flat on bottom  
         
24-04-2021 2 partners, 3 eggs in nest but accidentally no measurements taken.
         
26-04-2021 No visit, Camilla is trapping a Spoonbill.
         
06-05-2021 egg no: width (mm) length (mm) volume (cm3):  water test on April 16th:  
  A - - - 6 mm - floating.  
  B - - - 6 mm - floating.  
  C 48,4 66,1 77,96 2 mm - floating.  
      sum nest: 260,91    
         
13-05-2021 No visit, Camilla is trapping a Spoonbill.
         
15-05-2021 B egg & C egg present, and 1 chick (99 gr).
         
28-05-2021 Empty nest. Searched for chicks in vegetation, but not found.
         
02-06-2021 Guarding female near nest.

Visits and data 2022:
Estimation egg laying: A-egg = April 6 2022??? Estimating hatching = May 4 2022.

11-04-2022 Nest is ready, still no eggs.        
               
12-04-2022 From distance: adult guarding nest.        
               
  egg no: width (mm): length (mm): volume (cm3):  water test    
15-04-2022 A-egg 50,7 70,1 -- 20 - tip on bottom    
  B-egg 51,4 67,9   10 - tip on bottom  
sum nest: --
White jerrycan placed next to nest.  
   
  egg no: width (mm): length (mm): volume (cm3):  water test    
27-04-2022 A-egg -- --   3 mm - floating    
  B-egg -- --   2 mm - floating  
  C-egg 49,3 65,3   80 - tip on bottom
   
09-05-2022 From distance: adult at nest. Picture: bird has extra mirror, on P8.
   
17-05-2022   metal darvic mass wing H+B
pullus NLA 5.625.108 r-5.K 118    
pullus NLA 5.625.109 r-5.J 189    
               
17-06-2022 From distance: several larger chicks between blocks at this locations. No rings read, unfortunately.
       
21-06-2022 From distance: no activities at nest. No rings read, unfortunately.
 
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 21-2023 69,5 53,1 98,67 67,8 52,9 95,53 66,4 51,4 88,33 282,52 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 NLA 5556475 r-8.D
Pullus 11-05-2023 NLA 5556476 r-8.Y
Pullus 11-05-2023 NLA 5556477 r-8.E  
Pullus 18-06-2023 NLA 5556477 r-8.E
Pullus 18-06-2023 NLA 5556475 r-8.D
 
21-2023
dam: dam 1 T-split
location: Nest "white jerrycan in de oksel". Same as 21-2020/2022.
breeders: cach x cach
OBSERVATIONS:
09-04-2023 adult:  adult cachinnans at nest.
nest:  1 egg measured. No watertest.
26-04-2023 adult: 1x adult at nest.
eggs: 3x egg, measured. No water test, as ringing date known from A-egg date April 9th.
11-05-2023 pulli: 3 chicks ringed.
13-05-2023 adult both parents photographed: cach. Partner 1 with extra P8 mirror is same as 2022.
18-06-2023 pulli: large chicks r-8D and r-8E at nest site.
25-06-2023 pulli: r-8D and r-8E present. 2 chicks fledged.

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:
  cach cach 69,3 51,6 92,90 68,4 52,2 93,84 70,4 51,1 92,56 279,30
021-2024 # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 10-4-2024 7-5-2024
   
dam: dam 1 T-split
location: Nest "white jerrycan in de oksel". Same as 21-2020/22/23.
parents? same as 2023?
   
ring pulli: 12-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
14-05-2024 g-B|+ .5631195 nest 21 PONT 1CY 201          
14-05-2024 g-B|= .5631196 nest 21 PONT 1CY 199          
                           
OBSERVATIONS:
12-04-2024 eggs: 2 eggs, measured. 
21-04-2024 eggs: 3 eggs, measured. 
30-04-2024 adults: Caspian Gull at nest. Picture.
02-05-2024 eggs: 3 eggs.
07-05-2024 eggs: 3x.
14-05-2024 chicks: 2x ringed, 3rd chick dead in nest (died <3 days old).
31-05-2024 chicks: g-B|+ present.
18-06-2024 chick: CONTROLL: g-B|= at water.