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 251

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 251 positioned on dam 2 west section: 1 mtr N blue sign VHF20, 2 mtr behind "the white buoy". Could be parents nest 12-2020/2022.
  • ID uncertain in 2023: one parent is cachinnans, other parent unknown. Likely both cachinnans, but, might be Herring blood involved, as the chicks show intermediate traits.
location April 9th, 2023: nest location dam 2. April 9th, 2023: full clutch, with 3 eggs. .
   
partner 1 April 27th, 2023: breeding adult cachinnans. April 27th, 2023: adult cachinnans. .
   
pullus November 29th, 2023: fledged r[7.U]. June 25th, 2023: fledged g[7|V]. .
   

Data for nest 251-2023:

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 251-2023 70,7 50 88,99 68,1 51,4 90,59 67,7 49,1 82,18 261,76 was 12-2022???
ring pulli: May 10 laying A egg: April 05 hatch A egg: May 03
     
catch: date: metal: darvic: mass: wing: head+bill:
Pullus 11-5-2023 5.625.193 r-7.U 315 75.0 75.0 two other chicks? Chicks not found
Pullus 18-5-2023 5.556.411 g-7|V 490 86,3 86,3
Pullus 18-5-2023 5.625.193 r-7U not measured, but was present.
Pullus 27-5-2023 5.625.193 r-7U 896
Pullus 18-6-2023 5.625.193 r-7U
Pullus 18-6-2023 5.556.411 g-7|V
   
251-2023 nest "White Buoy".
dam: dam 2 west
location: 1 mtr N blue sign VHF20, 2 mtr behind of white buoy. Could be parents nest 12-2020/2022. Parents guarding from VHF20?
breeders: cach x cach
OBSERVATIONS:
09-4-2023 nest: 3 eggs measured. Watertest C-egg: 35 - tip bottom
27-4-2023 adult: breeding adult cach.
11-5-2023 pulli: 1 chick ringed r-7U, 2 more chicks?
18-5-2023 pulli: 2 chicks present. 1 ringed (R-7U), other unringed. The unringed one is now ringed today g-7|V.
27-5-2023 pulli: 1x chick measured, r-7U.
18-6-2023 pulli: g-7|V and r-7U together.
25-6-2023 pulli: G-7|V and r-7U together: 2 chicks fledged from this nest.