Larus cachinnans in the Netherlands

(last update: August 16, 2020)

Coordinator:
Albert de Jong
Merijn Loeve
Roland-Jan Buijs
Leon Kelder
Mars Muusse

Home

Cachinnans - nest Lelystad 021

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 021 positioned at breakwater 1 at T-split corner near Spoonbills. In 2021 position of nest is exactly the same, marked with "the grey jerrycan" from flotsam.
  • ID in 2020 certain, Caspian Gull cachinnans; one partner with sub-adult patterns. In 2021: 2 partners are adult Caspian gull cachinnans.
  • Both 2021 ringed chicks quickly after fledging reported from abroad (click links on pulli thumbnails below).
  • ID in 2022 uncertain. One parent is Caspian Gull, other parent not photgraphed.

below: Caspian Gull cachinnans adult, April 27 2020, Lelystad, the Netherlands. Picture: Albert de Jong.

Albatrossing to the partner flying overhead. On the right: adult Lesser Black-backed Gull breeder on nest 22, and some Spoonbills in the background.

location April 27th, 2020: nest location. May 7th, 2020: nest location. April 27th, 2020: 3 eggs clutch.
 
location April 16th, 2021: 2 eggs clutch. . .
     
partner 1 May 7th, 2020: male cachinnans 4CY? May 7th, 2020: male cachinnans 4CY? May 7th, 2020: male cachinnans 4CY?
 
partner 1 April 16th, 2021: male cachinnans. April 16th, 2021: male cachinnans. .
   
partner 2 May 7th, 2020: female cachinnans. May 7th, 2020: female cachinnans. .
   
pulli May 21st, 2020: pullus n[F|2]. May 21st, 2020: pullus n[F|4]. .
   

Visits and data.

date: egg no: width (mm) length (mm) volume (cm3):  water test on April 15th:  
27-04-2020 A 49,6 68,9 85,35 30 - angled, tip on bottom 3 eggs in the nest. Male with sub-adult pattern.
27-04-2020 B 49,8 70 87,41 60 - angled, tip on bottom  
27-04-2020 C 50,1 66,6 84,17 35 - angled, tip on bottom
  sum nest: 256,92
21-05-2020 pulli     Two chicks, ringed n[F|2] & n[F|4]. C-egg is unfertile, taken from nest.
         
02-06-2020 pulli     Two partners at nest.
         
date:        
16-04-2021 egg no: width (mm) length (mm) volume (cm3):  water test on April 16th:  
  A 50,5 70,9 91,04 20 - flat on bottom 2 eggs in the nest and 1 adult. Eggs just laid.
  B 49,5 74,5 91,91 15 - flat on bottom  
         
24-04-2021 2 partners, 3 eggs in nest but accidentally no measurements taken.
         
26-04-2021 No visit, Camilla is trapping a Spoonbill.
         
06-05-2021 egg no: width (mm) length (mm) volume (cm3):  water test on April 16th:  
  A - - - 6 mm - floating.  
  B - - - 6 mm - floating.  
  C 48,4 66,1 77,96 2 mm - floating.  
      sum nest: 260,91    
         
13-05-2021 No visit, Camilla is trapping a Spoonbill.
         
15-05-2021 B egg & C egg present, and 1 chick (99 gr).
         
28-05-2021 Empty nest. Searched for chicks in vegetation, but not found.
         
02-06-2021 Guarding female near nest.