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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Project Info
International trend
National trend
Site characteristics
Breeding biology
Fecundity
Food resources
Nonbreeding season
Breeding species
Hybrid scores
Ring codes
Future

Lelystad 2020:
nest 001
nest 002 yPNED
nest 003
nest 005 yPLDP
nest 006 yPESV
nest 008 gXLDT
nest 009
nest 011
nest 012
nest 013
nest 014
nest 015
nest 016
nest 017
nest 018
nest 021
nest 025
nest 027
nest 028
nest 029
nest 031
nest 032
nest 033
nest 034
nest 035
nest 036
nest 037
nest 038
nest 039
pair A
pair B

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 g-A|G (038)

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 038 positioned at breakwater 2 in 2020, outside research quadrant. Just 30 meters west of T-split near Elderberry. Discovered late in the season. Code marked at tarmac.
  • Nest location of previous years destroyed, this nest is 250 m eastwards in 2022.
  • Nest location 2023 same as 2022.
  • ID 2020 uncertain, one adult is Caspian Gull cachinnans. Female is argenteus-type, with strong argenteus influences.
  • Female 2020 = female 2021 100% certain. Male 2020 is 60% certain male 2021 (limited documentation for 2020).
  • ID 2022: both cachinnans. Female has thinner band on P5, male has more compact band on P5, compared to 2021.
  • ID 2023: female cachinnans & cachinnans hybrid type, as in 2022.
  • ID 2024: female cachinnans & cachinnans hybrid type, as in 2022/2023. In 2024 female trapped:g-A|G.
location Nest near tree April 24th, 2021. April 9th, 2023: nest near rock (same as 2022). April 26th, 2023: nest location.
 
eggs Eggs April 24th, 2021: 3 eggs clutch. Eggs April 26th, 2023: 3 eggs clutch. .
   
partner 1 June 2nd, 2020: hybrid-type. June 2nd, 2020: hybrid-type. June 2nd, 2020: hybrid-type.
 
partner 1 April 24th, 2021: hybrid-type. April 24th, 2021: partners. June 17th, 2022: partners.
 
partner 1 June 17th, 2022: female cachinnans. June 17th, 2022: female cachinnans. April 9th, 2023: female cachinnans.
 
partner 1 April 9th, 2023: female cachinnans. April 23 2024: female cachinnans. April 30 2024: female cachinnans trapped:g-A|G.
 
partner 2 May 21st, 2020: cachinnans. April 24th, 2021: cachinnans. May 13th, 2021: cachinnans.
 
partner 2 June 17th, 2022: male cachinnans. June 17th, 2022: male cachinnans. April 9th, 2023: male cachinnans.
 
partner 2 April 9th, 2023: male cachinnans. April 23 2024: cachinnans, but broad medial band P10. April 23 2024: male cachinnans.
 
pullus May 21st, 2020: pullus b[F|G]. May 21st, 2020: pullus b[F|H]. May 15st, 2021: pullus hatched A-chick.
 
pullus May 28th, 2021: b[F|J] and b[F|K]. June 26th, 2021: b[F|K]. May 22nd, 2022: pullus r-6.R.
 
pullus May 22nd, 2022: pullus r-6.P. 2023 fledged juvenile G-7|2. 2023 fledged juvenile R-8.K.
 
pullus June 18 2024: pullus g-B|N. May 14 2024: pullus g-B|P. June 18 2024: pullus g-B|R.
 
food Food 2020: Round Goby. May 14 2024: Perch and Roach-type. May 14 2024: Chick threw up fish.
 
food June 04 2024: fish = Roach. . .
     

Visits and data.

date:              
21-05-2020 Two pulli found, ringed b[F|G] & b[F|H]. Food: Round Goby, wrap of pork sausage. Both adults overhead alarming. Both unringed.
02-06-2020 Adult with at least one ringed pullus at location. We didn't manage to read the code.
               
16-04-2021 Nest checked. No eggs. Adult present: female cachinnans-type same as last year.
  egg no: width (mm): length (mm): volume (cm3):  water test on April 24th: laying date:  
24-04-2021 A 51,9 74,0 100,36 40 - tip bottom    
24-04-2021 B 51,9 75,4 102,26 50 - tip bottom  
24-04-2021 C 51,1 71,8 94,40 30 - tip bottom  
sum nest: 297,02
06-05-2021 Female present. 3 eggs in tact.
13-05-2021 2 partners present. Male is brutal cachinnans.  
15-05-2021 1 egg in tact.  
15-05-2021 1 egg hatching.  
15-05-2021 1 hatched chick. Mass = 75 gr.  
    metal ring darvic ring mass head + bill  
28-05-2021 pullus .5559376 b-F|J 554 85,8 Thrown up prey from chick: worms and fish.
28-05-2021 pullus .5559377 b-F|K 546 83  
           
08-06-2021 No visit.  
metal ring darvic ring mass head + bill wing  
26-06-2021 pullus .5559377 b-F|K 1174 125,5 363 retrapped chick and controlled.
               

In 2022, construction works (removal of trees and bushes) destroyed old location. In 2022, this nest is in LBBG section, east of T-split on dam 2. Nest with large boulders.
Nest located late in breeding season 2022.

Visits and data 38-2022:
               
metal darvic mass wing H+B  
22-05-2022 pullus .5625166 r-6P 303 58 73,2  
pullus .5625167 r-6R 253 45 71,7  
17-06-2022 2x pullus dead, both r-6P & r-6R. Bird flu?
             
 
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 hybrid 38-2023 69 50 86,85 68,6 52 93,40 67,8 51,9 91,95 272,20 same as 2022
ring pulli: 14-mei laying A egg: 11-apr hatch A egg: 9-mei
     
catch: date: metal: darvic: mass: wing: head+bill:      
Pullus 11-5-2023 NLA 5.556.468 R-8.K (on 18-5) 235 (on 18-5) 67
Pullus 18-5-2023 NLA 5.556.421 G-7|2 152 59,8
Pullus 18-6-2023 NLA 5.556.468 R-8.K 1077 328 122,4
Pullus 18-6-2023 NLA 5.556.421 G-7|2 887 311 112,7
 
038-2023
dam: dam 2 east of T-split
location: 2 large boulders, west one is lookout post, 200 mtr E of T-split, on top of tarmac. Red flag at N-side between blocks.
breeders: cach x river gull
OBSERVATIONS:
09-4-2023 2 adults cach type & river gull type on lookout. No eggs, but nest is ready.
26-4-2023 eggs: 3x egg, measured. Water test: A: floating - halfway
B: 80 - tip bottom
C: floating - 1mm
11-5-2023 pulli: 1 chick ringed, 1 egg hatching, 3rd egg still complete.
18-5-2023 pulli: 2 chicks present (R-8K and unringed one, which is now ringed g-7|2) 1 rotten egg.
18-6-2023 pulli: 2x fledged from nest (1x rotten egg).
25-6-2023 pulli: r-8K 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:
g-A|G (038) cach cach-type 70,3 53,3 100,56 68,4 51 89,58 70,6 52,8 99,10 289,23
2024 # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 11-4-2024 9-5-2024
   
dam: dam 2 east of T-split
location: Is 38-2023: 200 mtr E of T-split, on top of tarmac two large boulders, west one is lookout post.
parents? same as 2022, 2023. In 2024 female trapped:g-A|G
   
ring pulli: 14-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
30-04-2024 g-A|G .5625296 Dam 2 soos nest PONT F >4CY 424 1002 125,7 53,5 68,3 19 7
14-05-2024 g-B|N .5631167 nest 38 PONT 1CY 110          
14-05-2024 g-B|P .5631168 nest 38 PONT 1CY 88          
14-05-2024 g-B|R .5631169 nest 38 PONT 1CY 99          
                           
OBSERVATIONS:
12-04-2024 eggs: 1 egg, measured. 
21-04-2024 eggs: 3 eggs, measured. 
30-04-2024 adults: trapped female Caspian Gull, incubating 3 eggs. Now g-A|G.
07-05-2024 nest: 3 eggs, cracks.
14-05-2024 chicks: 3x ringed and measured.
04-06-2024 chicks: 3x ringed chicks present.
18-06-2024 chicks: 3x ringed chicks present.
adult: father guarding chicks.