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 231

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 231 positioned on dam 2 - west: low on blocks just 5 meters southwest of nests 203 & 204, and right beneath nest 229.
  • ID uncertain in 2022: one parent is cachinnans, other parent unknown.
  • ID certain in 2023: both parents are cachinnans. Nest aka "nest with orange football".
  • ID in 2024: both parents are same cachinnans as in 2023. Female trapped in 2024, now g-A|C.
location April 29th, 2022: location of nest. April 29th, 2022: location of nest. April 29th, 2022: 2 eggs.
 
partner 1 May 1st, 2022 adult cachinnans at nest. April 21st, 2024: location of nest. April 21st, 2024: full clutch, with 3 eggs.
 
partner 1 May 1st, 2022 adult cachinnans. May 1st, 2022 adult cachinnans. May 1st, 2022 adult cachinnans.
 
partner 1 April 27th, 2023 adult female cachinnans. April 27th, 2023 adult female cachinnans. April 27th, 2023 adult female cachinnans.
 
partner 1 April 23rd, 2024: female cachinnans. April 23rd, 2024: female cachinnans. April 26th, 2024: female cachinnans, now g-A|C.
 
partner 2 May 13th, 2023 male cachinnans type (or hybrid). May 13th, 2023 male cachinnans type (or hybrid). May 13th, 2023 male cachinnans type (or hybrid).
 
partner 2 April 23rd, 2024: male cachinnans-type. April 23rd, 2024: male cachinnans-type. April 23rd, 2024: male cachinnans-type.
 
pullus July 18th, 2023: fledged r[7.4]. July 18th, 2023: fledged r[7.5]. December 6th, 2023: fledged r[7.6].
 
pullus June 18th, 2024: chick g-B|G. June 18th, 2024: chick g-B|H. May 7th, 2024: chick g-B|J.
 
prey May 22nd, 2022: prey is fish. . .
     

Visits and data.

nest 231-2022 date A egg: April 14 hatch A egg: May 14 ring chicks: May 22
     
29-04-22 2 eggs A egg 67,8 49,7 tip bottom - 90 gr 5 mtr S of nests 203/204, low on blocks
B egg 60,8 48,5 tip bottom - 90 gr red spot + code sprayed near nest
01-05-22 adult cachinnans at nest.
17-05-22 mixed pair? Possibly cachinnans and argenteus at nest?
1 egg present, and likely 1 chick (but not found in vegetation).
22-05-22 1 egg is infertile
no chicks found, but fish prey at nest indicative of offspring.
prey: perch and roach.
17-06-22 adult cachinnans with 1x unringed chick (P7 fully grown / can not fly yet).
 
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 231-2023 66,7 50,5 85,65 66,5 51,9 90,19 66,1 52 89,99 265,83 No
ring pulli: laying A egg: hatch A egg
 
catch: date: metal: darvic: mass:          
Pullus 11-5-2023 5.556.451 r-7.4 very small chick
Pullus 11-5-2023 5.556.452 r-7.5 small chick
Pullus 11-5-2023 5.556.453 r-7.6 very small chick
Pullus 18-5-2023 r-74 present
Pullus 27-5-2023 5.556.452 r-75 730 wing: head+bill:      
Pullus 18-6-2023 r-74 1041 338 118,4
   
231-2023 nest 'orange football'. 
dam: dam 2 west
location: 5 mtr south of 203/204. Near waterfront
breeders: cach x cach
OBSERVATIONS:
04-04-2023 adult: 1 cach at nest location.
09-04-2023 nest: nest empty Water test:
26-04-2023 nest: 3 eggs. Measured & water test: A 90 - tip bottom
B 90 - tip bottom
27-04-2023 adult: breeding female cach C 80 - tip bottom
11-05-2023 pulli 3 chick ringed
13-05-2023 adult: 2x cach adults, 1 chick in nest, legs not visible.
18-05-2023 nest: R-74 present, other not found
18-06-2023 pulli r-74, r-75 & r-76 swimming together, only r-74 trapped & measured. Fledged: 3 chicks.
25-06-2023 pulli r-74, r-75 and r-76. All 3 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 70 52 95,30 67,9 50,9 88,57 68 51,5 90,81 274,68
231-2024 # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 4-4-2024 2-5-2024
   
dam: dam 2 west
location: was nest 'orange football' 2023,
parents? Same as 2023.
   
ring pulli: 6-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
26-04-2024 g-A|C .5625297 voetbal (231) PONT F >4CY 439 121,0 53,8 69,1 17,9 6
07-05-2024 g-B|G .5631154 231 football PONT 1CY 90          
07-05-2024 g-B|H .5631155 231 football PONT 1CY 147          
07-05-2024 g-B|J .5631156 231 football PONT 1CY 136          
                           
OBSERVATIONS:
21-04-2024 eggs: 3 eggs, measured.
26-04-2024 adult: adult female trapped at nest, now g-A|C.
02-05-2024 eggs: 2 eggs, 1x hatched halfway.
chicks: 1 chick, hatched this morning.
07-05-2024 chicks: 3x ringed.
04-06-2024 pullus: g-B|J dead, >7 days. Rings removed.
  adult: 2x, both parents in territory.
18-06-2024 chick: CONTROLL: g-B|G at water, g-B|H at blocks near territory.