Larus cachinnans in the Netherlands

(last update: August 16, 2020)
Coordinator:
Albert de Jong
Merijn Loeve
Roland-Jan Buijs
Thijs Horst
Leon Kelder
Mars Muusse

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Breeding biology
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Breeding species
Hybrid scores
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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 019

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 019 positioned high on artificial breakwater dam 1, 20 meters west of y-PNED. Nest in dense complex of Blackberry vegetation, with cluster with Spoonbills.
  • Nest marked with red flag. Location is close to nest 36-2020. Subsequent years: nest 19-2022 and 19-2023 at exact same spot on dam 1.
  • ID in 2021 certain: both partners are Caspian Gull cachinnans.
  • ID in 2022 certain: both partners are Caspian Gull cachinnans, likely same as in 2021.
  • ID in 2023 uncertain: one partner is Caspian Gull cachinnans, female might be Herring Gull argenteus. Supported by plumage of juvenile g-8|U with Herring traits.
  • ID in 2024 certain: male is Caspian Gull cachinnans (maybe supposed partner 2022?). Female is Herring Gull argenteus (white prim covs).
location Nest between Spoonbills, April 26, 2021. April 19th, 2022: nest location. June 8th, 2021: partners & 2 chicks at blocks.
 
  April 26th, 2023: nest location. April 26th, 2023: nest location. April 30th, 2024: nest location.
 
eggs Eggs April 16th, 2021: 3 eggs clutch. April 27th, 2022: 3 eggs. April 26th, 2023: 1 egg.
 
eggs April 23rd, 2024: 1 egg. April 23rd, 2024: 1 egg. .
   
partner 1 June 8th, 2021: partner 1 = male cachinnans. June 8th, 2021: partner 1 = male cachinnans. June 8th, 2021: partner 1 = male cachinnans.
 
partner 1 April 27th, 2022: partner 1 = male cachinnans. May 1st, 2022: partner 1 = male cachinnans. May 4th, 2022: partner 1 = male cachinnans.
 
partner 1 April 30th, 2024: male cachinnans. April 30th, 2024: male cachinnans. May 17th, 2024: male cachinnans.
 
partner 2 April 26th, 2021: female in Blackberry complex. June 8th, 2021: partner 2 = female cachinnans. June 8th, 2021: partner 2 = female cachinnans.
 
  April 27th, 2022: partner 2 = female cachinnans. April 27th, 2022: partner 2 = female cachinnans. April 27th, 2022: breeding female cachinnans.
 
partner? On May 6th, 2021, we assumed this to be one of the partners: male Caspian Gull cachinnans. Note different P5 pattern. April 30 2024: near-adult Herring Gull. April 30 2024: near-adult Herring Gull.
 
pullus May 9th, 2022: pullus r[5.U]. May 9th, 2022: pullus r[5.V]. June 18th, 2023: g[8|S]. Head wound.
 
pullus June 18th, 2023: g[8|T]. Checked upon by Herring. July 8th, 2023: g[8|U]. June 4th, 2024: g[M|E].
 
pullus June 4th, 2024: g[M|F]. . .
     

Visits and data.

date:              
  egg no: width (mm): length (mm): volume (cm3):  water test on April 16th: laying date:  
16-04-2021 A 48,4 70,9 83,63 30 - tip bottom   3 eggs in nest.
16-04-2021 B 50,5 70,8 90,91 50 - tip bottom  
16-04-2021 C 49,4 68,8 84,54 55 - tip bottom  
sum nest: 259,07
       
26-04-2021 1 parent present at nest, between Spoonbills.
       
13-05-2021 No visit, Camilla is catching a Spoonbill.
   
06-05-2021 Picture of one partner: male cachinnans.
   
15-05-2021 No visit, thunder coming in.
   
28-05-2021 No visit.
   
08-06-2021 2 large pulli & 2 parents on the blocks near the waterfront at north side. Next time, easy to trap.

Visits and data 2022 for nest 19:
Estimation egg laying: A-egg = April 03 2022. Estimating hatching = May 01 2022.

date:              
  egg no: width (mm): length (mm): volume (cm3):       
15-04-2022 A 49,8 68,3 -- 90 - tip bottom 3 eggs  
  B 50,4 69 -- 90 - tip bottom  
C 48,2 68,1 -- 90 - tip bottom
sum nest: --
   
19-04-2022 3 birds present: including female w-327:U without nest.
   
27-04-2022 A -- -- -- 3 mm - floating 3 eggs  
  B -- -- -- 3 mm - floating  
C -- -- -- 4 mm - floating
parent 1 = cachinnans.  
   
01-05-2022 2 parents at nest.  
   
04-05-2022 male = cachinnans.  
   
09-05-2022 Nest is empty, no chicks found, but much shit; the chicks hide in Blackberry complex.
   
    metal darvic mass H+B    
17-05-2022 pullus 5.625.119 r-5V 404 80,5    
  pullus 5.625.120 r-5U 464 82,5  
         
   
17-06-2022 No birds present.
   
21-06-2022 No activity at nest.
 
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 teus 19-2023 74,6 53,1 105,91 0 0 0,00 0 0 0,00 105,91 new birds
ring pulli: 27-05-2023 laying A egg: 26-04-2023 hatch A egg: 24-05-2023
 
catch: date: metal: darvic: mass: wing: head+bill:
Pullus 27-05-2023 5.625.263 g-8|T 160 -- --
Pullus 27-05-2023 5.625.265 g-8|U 80 -- --
Pullus 27-05-2023 5.625.267 g-8|S 125 -- --
Pullus 18-06-2023 5.625.265 g-8|U -- -- --
Pullus 18-06-2023 5.625.263 g-8|T 765 205 103,6 Herring type. With HG parent (?) later this date.
Pullus 18-06-2023 5.625.267 g-8|S -- -- -- Bleeding head wound, not measured.
Pullus 25-06-2023 5.625.265 g-8|U 847 241 109
 
19-2023
dam: dam 1 east
location: Low on N-side of dam. In blackberry complex. Location is nest 19-2020/22, old code still readable.
breeders: cach x teus
OBSERVATIONS:
09-04-2023 adult: 2 unringed cach present at blocks on N side, in front of location. Search for nest today.
26-04-2023 nest: same location, old codes still present. Refreshed with spray.
eggs: 1x egg, egg is cold. Nest abandoned? Egg measured.
comment: This used to be an early nest, 3 eggs should be floating already this date. In retrospect: late, as one parent is now Herring Gull?
13-05-2023 adult: partner 1 = cach adult.
18-05-2023 nest: 3 eggs.
27-05-2023 pulli: 3x chicks ringed and measured.
18-06-2023 pulli: 3x chicks present, but not in category 'fledged', still too young.
pullus: g-8|S with terrible head wound, therefore not measured. Will probably not survive.
pullus: g-8|T between blocks, was checked upon by adult Herring Gull, close to nest site. Hence: at least one parent is Herring!?
25-06-2023 pullus: g-8|U caught and measured.

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:
019-2024 cach teus 75,7 53,3 108,28 77 52,2 105,64 72,6 51,6 97,33
311,25
  # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 22-4-2024 20-5-2024
   
dam: dam 1 east
location: was 19-2023, N side dam.
parents? same as 2023?
   
ring pulli: 24-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
04-06-2024 g-M|E .5631137 nest 19 cach x teus 1CY 84 438 86        
04-06-2024 g-M|F .5631138 nest 19 cach x teus 1CY 118 596 89,8        
                           
OBSERVATIONS:
23-04-2024 eggs: 1 egg, measured. 
26-04-2024 eggs: 3 eggs, measured. 
adults: Herring Gull on blocks in front of nest, bird with white primary coverts.
30-04-2024 adults: Herring Gull on blocks in front of nest, bird with white primary coverts.
14-05-2024 adults: Herring Gull poresent again.
04-06-2024 chicks: 2x ringed & measured.