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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Cachinnans - nest Lelystad r-7.P & b/w-AB(154)

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 154 positioned on dam 1 western section. Most western nest for 2023.
  • ID certain in 2023: male parent is Caspian Gull, female parent is Herring Gull. Adult male Caspian Gull trapped at nest in 2023, now r[7.P].
  • ID certain in 2024: male r[7.P] is Caspian Gull, female parent is Herring Gull b/w-AB.
  April 21st, 2024: 3 eggs. April 21st, 2024: 3 eggs. April 21st, 2024: r-7P & unringed Herring Gull.
 
partner 1 April 27th, 2023: adult male Caspian Gull r[7.P]. May 3rd, 2023: adult male Caspian Gull r[7.P] ringed. May 3rd, 2023: adult male Caspian Gull r[7.P] ringed.
 
partner 2 April 26th, 2024: trapped female Herring Gull, now b/w-AB. April 26th, 2024: trapped female Herring Gull, now b/w-AB. April 26th, 2024: trapped female Herring Gull, now b/w-AB.
 
pullus September 20th, 2023: hybrid pullus r[8.+] fledged. . .
     
pullus May 14th, 2024: pullus g-C|R. May 14th, 2024: pullus g-C|T. May 14th, 2024: pullus g-C|U.
 

Visits and data.

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 154-2023 74,6 51 97,70 70,6 51,9 95,75 55,2 50,5 70,88 264,33 NEW NEST
ring pulli: laying A egg: hatch A egg
 
catch: date: metal: darvic: mass: wing: head+bill: bill: gonys: greytone:
adult 03-05-2023 6214907 r-7.P nn 449 137,2 62,2 21,3 7 male cachinnans.
pullus 18-05-2023 5556485 r-8.+ 124 56
pullus 27-05-2023 5556485 r-8.+ 329
   
154-2023 NEW NEST
dam: dam 1 west
location: most western nest selected in 2023 at dam 1.
breeders: cach x teus
OBSERVATIONS:
22-04-2023 nest: 3 eggs, water test: flat bottom - 3 times (recently laid).
27-04-2023 adult: Male cachinnans & female argenteus. Female breeding.
03-05-2023 adult: Trapped male cach at nest: r-7.P
13-05-2023 adult: Cachinnans r-7P guarding, female teus incubating.
18-05-2023 pullus: 1 chick ringed, other 2 not found
27-05-2023 pullus: 1x control chick.

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:
r-7.P & b/w-AB cach teus 71,4 51,7 96,09 68,6 51 89,84 70,3 52,4 97,19 283,12
2024 # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 16-4-2024 14-5-2024
   
dam: dam 1 south
location: far western nest in 2023 & 2024.
parents? same as 2023
   
ring pulli: 18-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
26-04-2024 b/w-AB .5625285 nest r-7P teus F >4CY 403 119,2 51,5 64,7 18,6 5
31-05-2024 g-C|R .5631118 r-7P b/w-AB cach x teus 1CY              
31-05-2024 g-C|T .5631119 r-7P b/w-AB cach x teus 1CY              
31-05-2024 g-C|U .5631120 r-7P b/w-AB cach x teus 1CY              
                           
OBSERVATIONS:
08-03-2024 adult: r-7P & argenteus female.
12-04-2024 eggs: empty nest, but is ready.
21-04-2024 eggs: 3 eggs, measured.
26-04-2024 adult: partner trapped at nest.
14-05-2024

eggs:

2 eggs.
chicks: 1x, just hatched.
31-05-2024 chicks: 3x ringed.
18-06-2024 adult: female b/w-AB present.