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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Lelystad 2021
nest y-PNED
nest y-PLDP
nest y-PHSV
nest y-P:A02
nest y-P:U60
nest zy-MT
nest r-FB
nest r-FC
nest 001
nest 003
nest 006
nest 011
nest 012
nest 013
nest 014
nest 015
nest 016B
nest 017
nest 018
nest 019
nest 021
nest 034
nest 035
nest 038
nest 040
nest 041
nest 042
nest 044
nest 045
nest 046
nest 047
nest 048
nest 053
nest 055
nest 056
nest 058
nest 060
nest 062
nest 063
nest 065
nest 066
nest 067
nest 072

Nests at Lelystad 2022
nest y-PNED
nest y-PHSV / r-CG
nest y-P:U60
nest y-X56A
nest y-X71A
nest y-X540
nest y-XCHP
nest w-327:U
nest n-F|N
nest r-6A
nest r-6B
nest r-6C
nest r-CS
nest r-FC
nest w-8Z
nest zy-MT
nest 003
nest 011
nest 012
nest 014
nest 015
nest 017
nest 017B
nest 018
nest 019
nest 021
nest 026
nest 034
nest 035
nest 038
nest 040
nest 044
nest 046
nest 048
nest 053
nest 055
nest 058
nest 060
nest 061Z
nest 062
nest 063
nest 107Z
nest 109
nest 111
nest 112
nest 113
nest 117Z
nest 118Z
nest 123Z
nest 124Z
nest 125Z
nest 126Z
nest 127Z
nest 128Z
nest 129Z
nest 131Z
nest 132 YLG
nest 133
nest 134
nest 135
nest 136
nest 137
nest 138
nest 139
nest 143Z
nest 203
nest 204
nest 207
nest 222Z
nest 227
nest 228Z
nest 229
nest 230Z
nest 231
nest 240Z
nest 244
nest 245Z

Lelystad 2023:
nest y-PNED
nest y-P:U60
nest y-X56A
nest y-X71A
nest y-X60J
nest y-XCHP
nest w-327:U
nest n-F|6
nest n-F|8
nest n-F|+
nest n-F|N
nest r-6.B
nest r-7.P
nest r-C.G
nest w-8Z
nest 003
nest 006
nest 013
nest 014
nest 015
nest 017
nest 017B
nest 018
nest 019
nest 021
nest 026
nest 033
nest 034
nest 035
nest 038
nest 040
nest 044
nest 046
nest 048
nest 053
nest 055
nest 060
nest 061Z
nest 062
nest 063
nest 107Z
nest 108
nest 109
nest 111
nest 112
nest 127Z
nest 131Z
nest 132 YLG
nest 135
nest 139
nest 147Z
nest 163
nest 167
nest 168
nest 204
nest 206
nest 207
nest 223
nest 227
nest 230Z
nest 231
nest 244Z
nest 245Z
nest 248
nest 251
nest 252
nest 253
nest 254
nest 255Z
nest 256Z
nest 262

Cachinnans - nest Lelystad 017B

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 17B positioned high on breakwater dam 2, within dense Blackberry vegetation. In 2022: code 17B sprayed again on the block.
  • ID certain in 2021, one parent photographed, characteristics match pure Caspian Gull cachinnans.
  • ID certain in 2022, both parents are Caspian Gull cachinnans.
  • ID certain in 2023, Caspian Gull cachinnans are same as in 2022.
  • ID certain in 2024, female Caspian Gull cachinnans is same as in 2022/23.
location Nest location April 24th, 2021. April 29th, 2022: nest (from north). .
   
eggs April 29th, 2022: full clutch, nest with 3 eggs. April 9th, 2023: full clutch, nest with 3 eggs. April 21st, 2024: full clutch, nest with 3 eggs.
 
partner 1 April 24th, 2021: cachinnans female. April 19th, 2022: cachinnans female. April 19th, 2022: cachinnans female.
 
  May 13th, 2023: cachinnans female. May 13th, 2023: cachinnans female. .
   
  April 23rd, 2024: cachinnans female. April 23rd, 2024: cachinnans female. April 23rd, 2024: cachinnans female.
 
  May 02 2024: same male cachinnans as 2023. May 02 2024: same male cachinnans as 2023. May 02 2024: same male cachinnans as 2023.
 
partner 2 May 1st, 2022: cachinnans male. April 19th, 2022: cachinnans male. May 1st, 2022: cachinnans male.
 
  May 13th, 2023: "dark eyed" cachinnans male. May 13th, 2023: "dark eyed" cachinnans male. May 02 2024: same male cachinnans as 2023.
 
  May 02 2024: same male cachinnans as 2023. May 02 2024: same male cachinnans as 2023.  
   
chicks May 9th, 2022: pullus r[C.V]. May 9th, 2022: pullus r[C.W]. May 9th, 2022: pullus NLA 5.625.072.
   
  May 11th, 2023: pullus r[8.G]. May 27th, 2023: pullus r[8.G]. June 18th, 2023: pullus r[8.R].
 
pullus June 18th, 2024: g-A|K. May 31st, 2024: g-A|L. .
   
food: May 14th, 2024: fish bolus of chick g-A|L. . .
     
       

Visits and data 2021:

date:                
24-04-2021 Patrolling adult and landing at location. We did not climb the dam to search.
06-05-2021 No bird present.
15-05-2021 No bird present.
28-05-2021 No visit.
26-06-2021 No visit.
   
Visits and data 2022:
Estimation egg laying: A-egg = April 08 2022. Estimating hatching = May 06 2022.
                 
15-04-2022 A egg 68,1 50,4 tip bottom - 40 2 blue eggs.      
  B egg 65,6 49,7 tip bottom - 40        
  C egg 68,7 50,6 tip bottom - 40        
   
19-04-2022 2 parents present at nest.
   
29-04-2022 A egg     float - 1 mm        
  B egg     float - 1 mm        
  C egg     float - 1 mm        
   
01-05-2022 female is cachinnans.
   
09-05-2022 pullus r-C.V   NLA 5625070        
  pullus r-C.W   NLA 5625071        
  pullus --   NLA 5625072 pullus too small for plastic.
   
    colour   metal mass wing head + bill bill
17-05-2022 pullus r-C.V   NLA 5625070 257      
   
30-05-2022 pullus r-C.V   NLA 5625070 615 175 95,1 39,3
  food: fish is Roach
   
02-06-2022 male alarming.
   
17-06-2022 No birds near nest, r-CW flying around at north side.
   
21-06-2022 No activities near nest, r-CV & r-CW & 3rd chick (only mmetal?) swimming at north side. If so, then 3x chicks fledged from this nest.
   
12-07-2022 R-CV & r-CW photographed.
                 
17-05-2022 R-CW 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 17B-2023 67,8 50,4 86,71 69,2 48,5 81,96 68 51,3 90,10 258,78 same as 2022
ring pulli: 10-mei laying A egg: 5-apr hatch A egg: 3-mei
     
catch: date: metal: darvic: mass: wing: head+bill:      
Pullus 11-5-2023 NLA 5556462 r-8.G -- -- --
Pullus 11-5-2023 NLA 5556463 r-8.R -- -- --
Pullus 27-5-2023 NLA 5556462 r-8.G dead >7 days ago
Pullus 18-6-2023 NLA 5556463 r-8.R 1133 356 131,9
 
17B-2023
dam: dam 2 central
location: on S-side "17B" coded on block, path to top of dam, in Blackberry complex.
breeders: cach x cach
OBSERVATIONS:
04-04-2023 adult: 2 cach present.
09-04-2023 adult: 2 cach present.
nest:  Nest with 3 eggs. No watertest, ring chicks in 1st session.
26-04-2023 adult: 1 cach present.
nest:  3 eggs. Not measured.
11-05-2023 pulli: 2 chicks ringed, is there a 3rd chick?
13-05-2023 adult: pair present, same as 2022. Female spot on P10. Male dark eye.
18-05-2023 nest:  nest empty, no chicks found.
27-05-2023 pulli: dead chick near nest: r-8G.
18-06-2023 nest:  no birds present. R-8R trapped in water with net & measured. Fledged: 1 chick.
25-06-2023 pulli: r-8R present.

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 69,4 50,6 89,47 65,9 51 86,30 65 49 78,58 254,35
017B-2024 # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 17-4-2024 15-5-2024
   
dam: dam 2 central
location: 17B-2021, 2022, 2023
parents? Same birds
   
ring pulli: 21-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
02-05-2024 g-A|K .5631214 nest 17B PONT 1CY 63          
02-05-2024 g-A|L .5631214 nest 17B PONT 1CY 63          
14-05-2024 g-A|L .5631215 nest 17B PONT 1CY 409 CONTROLL        
                           
OBSERVATIONS:
21-04-2024 eggs: 3 eggs, measured. 
02-05-2024 eggs: 1x blue egg.
chicks: 2x chick ringed: g-A|K & g-A|L.
05-05-2024 chicks: blue egg gone, but only 2x ringed chicks found in vegetation.
14-05-2024 chicks: g-A|L is 409 gr. CONTROLL.
food: Blous: fish.
31-05-2024 chick: g-A|L at nest.
04-06-2024 nest: no chick found.
18-06-2024 chicks: g-A|K & g-A|L at water, and maybe the 3rd chick as well. Fledged: "at least" 2 chicks, likely 3 chicks.