A bird often mentioned as a potential vagrant to North America is the Mediterranean Gull Larus melanocephalus, a European species which has undertaken a westerly expansion from its core breeding range (which is still almost entirely in the Ukraine and Europe) since the 1950s. From Hungary, where it was breeding regularly by 1953, it spread into Germany and Belgium during the 1960s and the Netherlands by 1970. The first breeding occurrence of the Mediterranean Gull in Britain was in 1968, at Needs Ore Point (Hampshire), followed by a pair at Dungeness (Kent) in 1979, increasing to two pairs by 1985. Another site in north Kent was colonised in 1983, while scattered (and futile of course) breeding attempts with Black-headed Gulls L. ridibundus were noted along the UK’s south coast. The first breeding attempt in Ireland was in Antrim in 1995, followed by a pair nesting in Wexford in 1996.

The most likely age to turn up first in North America is an immature (on the principle that it’s usually young, inexperienced birds that wander outside the normal range, though of course if the species expands across the Atlantic any age could arrive). The following images of 1st winter Med Gulls were all taken at Radipole Lake in Dorset, UK in October 2009, except for the excellent photo which starts this series which was generously provided by Alan Tilmouth of (amongst other things) Dusted Off Bins.

I’ve also included two other images that I’ve posted before on 10,000 Birds (the Laughing Gull is from a gallery here) as I think the direct comparison may help…

1st winter Mediterranean Gull, NE England, 17 Sept 09.
Copyright Alan Tilmouth (Dusted Off Bins).

 

1st winter Black-headed Gull Larus ridibundus ridibundus
Chew Valley, UK. 07 Jan

 

1st winter Laughing Gull, Miami, Nov 07.

The usual challenge for birders in the UK looking for Med Gulls is separating them from Black-headed Gulls - a problem most North American birders probably won’t face of course - but it’s still useful to compare the two species (the very much darker and ‘longer’ Laughing Gull really shouldn’t be a problem as the above image shows). In close views they’re quite easy to distinguish, but it can be surprisingly difficult to pick out Med Gulls when you’re scanning through, say, a couple of hundred gulls on a cold, windy estuary as small Med Gulls aren’t much bigger than large Black-headed Gulls and using size as an ID feature is basically fairly useless.

So given that in the field they often appear similarly-sized what features can we use to separate the two species (note that the following points are comparing non-breeding 1st winter birds only)?

• Both species are essentially pale grey birds with dull reddish/dark reddish soft parts (note that while some Med Gulls show bi-coloured bills some have all dark bills and very dark legs), but the Med Gull is slightly bulkier, with darker tertials and coverts than the Black-headed.
• While both species have mostly pale heads in non-breeding plumages, the Mediterranean Gull has a distinctive “auricular bridle” - a band of dark feathers around the eye and around the back of the head, which though present in some Black-headeds is never as strong. Note also the distinctive white ‘eyelids’ of the Med Gull, a feature present even in juveniles: they are usually not so apparent in Black-headed Gulls.
• A feature that holds true in either breeding or non-breeding plumages is the head-shape and bill profile of a Med Gull compared with a Black-headed. Med Gulls have squarer heads and obviously shorter, thicker bills than Black-headed Gulls which - despite being one of the UK’s most beautiful gulls - give them a ‘meaner’ and more ‘business-like’ look.

1st winter Mediterranean Gull

 

1st winter Mediterranean Gull and adult non-breeding Black-headed Gull

 

1st winter Mediterranean Gull and adult non-breeding Black-headed Gull

 

(From foreground) 1st winter Mediterranean Gull, 1st winter Black-headed Gull, and adult non-breeding Black-headed Gull

 

(From foreground) 1st winter Black-headed Gull, 1st winter Mediterranean Gull, and adult non-breeding Black-headed Gull

 

(From foreground) 1st winter Mediterranean Gull, adult non-breeding Black-headed Gull, adult non-breeding Herring Gull

 

1st winter Mediterranean Gull (with adult non-breeding Mediterranean Gull in foreground)

In flight, Mediterranean Gulls more resemble Common Gulls than Black-headeds and are surprisingly easy to pick out of a crowd. They have broader, shorter wings than Black-headeds, a ’stiffer’ flight action, and their upperwings show distinctive dark outer primaries and greater coverts.

1st winter Mediterranean Gull

 

1st winter Mediterranean Gull

 

1st winter Mediterranean Gull

 

1st winter Mediterranean Gull

 

1st winter Mediterranean Gull

And finally one that is pretty useless for ID purposes but might just appeal to the more ‘arty’ amongst us…

As an aside, interestingly the scientific name of the Mediterranean Gull Larus melanocephalus translates as “black headed gull”, whilst the specific name of the Black-headed Gull ridibundus is Latin for “laughing”. So what does the scientific name of the Laughing Gull L. atricilla mean? Well, ater is Latin for black, and cilla…that’s Latin for ‘tail’ actually…

All photos except Alan Tilmouth’s 1st winter med Gull (labelled) copyright Charlie Moores 2009

For more of Alan Tilmouth’s photos please visit:
http://birdneast.blogspot.com
http://laridae.blogspot.com
http://dustybins.blogspot.com