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 163

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 163 positioned on section "dam 1 blocks", in NW part, below (north) of nest 53. Confusion in 2023 about which parents belong to which nest.
  • Nest 163-2024 next to Elderberry, called "nest Vliertje"
  • ID uncertain in 2023: one parent is sub-adult Caspian Gull cachinnans. Finally, agreed upon chicks r-87 and r-88 belowng to nest 53.
  • ID certain in 2024: male Yelow-legged Gull michahellis type; female Caspian Gull cachinnans.
  April 12th, 2024: 3 eggs clutch. April 21st, 2024: 3 eggs clutch. April 21st, 2024: red spot on boulder.
 
  April 21st, 2024: Caspian Gull incubating at "Vliertje". . .
     
partner 1 May 13th, 2023: adult cachinnans. May 13th, 2023: adult cachinnans. May 13th, 2023: adult cachinnans.
 
partner 1 May 02 2024: female Caspian Gull. May 02 2024: female Caspian Gull. May 02 2024: female Caspian Gull.
 
partner 2 May 13th, 2023: sub-adult cachinnans. May 13th, 2023: sub-adult cachinnans. May 13th, 2023: both parents are cachinnans.
 
partner 2 April 23rd, 2024: michahellis-type. April 23rd, 2024: michahellis-type. May 02 2024: michahellis-type.
 
partner 2 May 02 2024: michahellis-type. May 02 2024: michahellis-type. May 02 2024: michahellis-type.
 
pullus July 8th, 2023: weak juvenile r[8.7]. July 15th, 2023: juvenile r[8.8]. .
   
pullus June 18th, 2024: chick g-A|8. June 18th, 2024: chick g-A|9. May 7th, 2024: chick g-A|+.
 

Visits and data:

egg sizes & volume 2023
SPECIES NEST
cach x cach type 163-2023
   
163-2023 uncertainty about chicks: decision = nest 053.
dam: dam 1 
location: Blocks dam 1 - west section, under (north of) nest 53.
breeders: cach x cach type
OBSERVATIONS:
11-05-2023 pull 2 chicks ringed.
18-05-2023 puli R-87 was present
27-05-2023 pull Low on N-side, found again r-87 & r-88 from nest 163 (or from 53)? See notes on tab 53.
18-06-2023 pull r88 might be hybrid? Op blokken dam 1, west stuk, laag, op noord (dus wrschl niet van nest 53?), maar klimt omhoog.
25-06-2023 pull r-88 and r-87 both present
 
53-2023 / 163-2023 (likely 2 nests, but maybe all data for 1 pair only).
dam: dam 1 blocks
location: is nest 53/110, same as 2021/2022. Later in season chicks ringed little north of this spot, but then no Caspians higher on dam. Same couple?
breeders: cach x cach
OBSERVATIONS:
26-4-2023 nest: Refreshed red stripe on block, nest is 1,5 m south of red stripe.
eggs: 3x egg, measured. No water test.
11-5-2023 nest: 1 egg hatching, other 2 still complete, but many nests here. If this is the wrong nest, then maybe R-87 & R-88 from nest 163? In retrospect: yes, likely of 163.
18-5-2023 nest: Empty, no chicks found.
27-5-2023 nest: No shit at nest, no traces of chicks. Low on N-side, found again R-87 & R-88 from new nest number 163 (and likely not from 53)?
18-6-2023 pull: R-88 might be hybrid? See nest 163 (which is north of 53), for details on R-8.7 and R-8.8. Present on N-side, but walks up to location nest 53!

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 69,2 49,1 84,00 68,9 49,4 84,66 66,5 48,3 78,11 246,77
163-2024 # eggs A-egg hatch # ringed chicks # all chicks # fledged chicks comments
  3 8-4-2024 3-5-2024
   
dam: dam 1 blocks
location: Blocks dam 1 - west section, under (north of) nest 53, near (east of) Elderberry near waterfront.
parents? same as 2023?
   
ring pulli: 09-May
date darvic metal location / nest# species sexe age wing mass head+ bill bill tarsus gonys greyscale
07-05-2024 g-A|8 .5631241 163 PONT 1CY 121          
07-05-2024 g-A|9 .5631242 163 PONT 1CY 75          
07-05-2024 g-A|+ .5631243 163 PONT 1CY 116          
                           
OBSERVATIONS:
12-04-2024 eggs: 3 eggs, measured. Small eggs.
21-04-2024 eggs: 3 eggs, not measured.
adult: Caspian Gull incubating.
02-05-2024 eggs: 3 eggs.
adult: female Caspian Gull. Male much black on P10 and P8, broad band on P5, with dark iris, red orbital and gape.
07-05-2024 chicks: 3x ringed.
18-06-2024 chicks: 3x present: g-A|8, gA|9 & g-A|+.