Larus cachinnans

(last update: February 16, 2013)

Coordinator:
Peter Adriaens (Belgium)
Ies Meulmeester (Netherlands)

Home

cachinnans plumages

Larus cachinnans 4P13 adult, May 05 2014, Zastów Karczmiski, Poland. Picture: Łukasz Bednarz ringing team.

Please visit Łukasz's BLOG for beautiful drawings and up-to-date gull news from eastern Poland: Wildlife art and illustration

Location: Zastów Karczmiski, Poland - colony at the banks of the Middle Vistula river.
In 2004 240 breeding pairs (95% cachinnans, <5% argentatus). (Ornis Fennica 2011 88, 80-89) and in 2012 592 pairs (90% cachinnans, <10% hybrid / argentatus) and possibly Larus michahellis (pers comm. Łukasz Bednarz).

Middle Vistule river is a location where several taxa breed: see composition. Since this is a mixed breeding population where hybridisation is not uncommon, the ringing centre in Poland decided to label birds "Larus argentatus sensu lato". Still bulk of the breeding birds in Middle Vistula region show features of cachinnans.

Breeding bird trapped at the nest. Adult, with moderate speckling in iris. Orange-red orbital ring and gape. Faint red on upper mandible; black on the upper and on the lower mandible. Pink legs with yellow hue.
Deep white tongue on P10 (almost creating thayeri pattern = medial band is broken), black spot on P5; no spot on P4. P1 dropped, PMS=1.