Moerdijk Field Research 2005-2006
(last update: 14 August 2010)
Roland-Jan Buijs
Theo Muusse
Mars Muusse
Introduction
Methods
Age, origin & sex
Retrapped Birds
Upperparts Greytone
Black on Primary Coverts
Black on Primaries
P10 and P9 Patterns
P5 Pattern
Red & Black on Bill
Iris & Orbital Ring
Primary Moult
Discussion
References
In what way do Dutch Lesser Black-backed Gulls resemble Heuglin's Gull (heuglini)? Starting point is the 2002 article in British Bird by Valery Buzun.
Winter Heuglin's Gulls at the Arabian peninsular, images Chris Gibbins.
The image below, plots the upperparts grey tone for heuglini (Kodak 7-11) between Herring Gull and average Moerdijk graellsii. It appears heuglini is on the pale end of Dutch graellsii.
And the image below illustrates the overlap in number of primaries showing black markings. Only on average there is more black in heuglini.
Continue at: P9 & P10 PATTERNS for heuglini.