Interesting opportunity to identify a 4th winter Mediterranean Gull on plumage!

It’s great how bird species you see reasonably frequently can sometimes throw you another lesson! I was always under the impression that Mediterranean Gulls were only identifiable in as juvenile/1st winter, 2nd winter/2nd summer and adult winter/adult summer. However when Chris Hind found a Mediterranean Gull in transitional 1st summer <-> 2nd winter plumage; none of us realised that this distinctive individual was going to teach us a bit more.

Chris Hind stuck with this bird as it returned every year subsequently and has managed a really useful set of images and sourced some interesting pieces of information through his own research and discussion with others (notibaly Derek Charles).

Chris has put together the following account of his observations and collective research:

The Workington Mediterranean Gull : Ageing sequence

The regular Mediterranean Gull at Workington has provided an interesting opportunity to observe the succession of plumages through from first summer to its present near-adult state.

I found this bird on 30th July 2009, it lingered around the harbour car park and allowed for photographs both in flight and perched.  It was a distinctive individual in having a damaged left leg which was not functional and resulted in the foot projecting visibly from the plumage of the belly both in flight and when perched.  The left leg carried a metal ring.

The plumage state at that time was first-summer moulting into second-winter.                                      

The 1st summer features visible were:

  • Head showing considerable dark mottling but falling short of a full hood.
  • Outer tail feathers with dark sub-terminal band
  • Dark secondary band
  • Outer four primaries dark

The 2nd winter features becoming visible were:

  • White central tail feathers
  • White inner primaries
  • White tertials

Mediterranean Gull (Workington Harbour) - Ist summer/2nd winter transitional plumage © Chris Hind

Mediterranean Gull (Workington Harbour) - Ist summer/2nd winter transitional plumage © Chris Hind

When I photographed the bird next on 23rd September 2009 it was well into 2nd winter plumage.  The outer primaries, P8, P9 and P10 were not fully grown.  This gave the bird a rather truncated look when perched and a blunt-winged appearance in flight.

Mediterranean Gull (Workington Harbour) - 2nd winter © Chris Hind (23rd September 2009)

Mediterranean Gull (Workington Harbour) - 2nd winter © Chris Hind (23rd September 2009)

By 22nd December the primaries were all fully grown.  The distribution of black on the four outer primaries is typical of a bird of this age.  This wing pattern is retained through the third summer until the fourth winter. 

Mediterranean Gull (Workington Harbour) - 2nd winter © Chris Hind (22nd December 2009)

Mediterranean Gull (Workington Harbour) - 2nd winter © Chris Hind (7th January 2010)

Mediterranean Gull (Workington Harbour) - 2nd summer © Chris Hind (7th July 2010)

In its third winter it showed black outer webs to the three outer primaries, P8, P9 and P10.  Most Mediterranean Gulls are in full adult plumage by this age and would show a thin black line on the outer web of P10 only.  There is a 50% incidence of black on the three outer primaries in females and a 25% incidence of this in males. (Olsen 2004)

Mediterranean Gull (Workington Harbour) - 3rd winter © Chris Hind 12th December 2010)

By the fourth winter a Mediterranean Gull would certainly be expected to be in full adult plumage.  The Workington gull, however, shows a small dark mark on the outer web of each P9 in addition to the normal dark line on P10.

Mediterranean Gull (Workington Harbour) - 4th winter © Chris Hind 18th December 2011)

Mediterranean Gull (Workington Harbour) - 4th winter © Chris Hind 18th December 2011)

The ringing details of this bird were eventually forthcoming after 18 months of frustratingly fruitless emails !

It was ringed on 27th May 2008 as a nestling (sex unknown) at Kieldrecht, Oost-Vlaanderen, Belgium.

 Chris Hind

Cumbria, 2012

This is a fascinating bird to see and a great example of how much we have to learn!

5 thoughts on “Interesting opportunity to identify a 4th winter Mediterranean Gull on plumage!

  1. Pim Wolf

    Nice one, not very rare in Med Gull but not much has been published on 4th winter plumage. Mind you, some will look like this in 3rd or 5th winter so do not get to sure about the age of a bird with this plumage. Unless you read the ring of course! Question to Chris, to whom did you send all those fruitless emails? The Belgian Med Gull ringers are usually very cooperative and eager to get a ring reported (even when there are well over 150.000 sightings of colour-ringed birds in the database).

    Reply
    1. Chris Hind

      Hi Pim
      Thanks. I emailed the BTO with the ring details.
      Most of the readable Med. Gull rings have been colour rings. The Hamburg group have been brilliant and one of their birds has been back to Workington every August for the past 3 years and has gone on to Spain/Portugal for the winter before heading back to Hamburg for the breeding season.
      I am still waiting for details of one ringed in Poland from Feb. 2010 …..
      Regards
      Chris

      Reply
  2. Pete Kinsella

    Interestingly, what appears to be the same Med was present at Seaforth NR, Merseyside on the 15th April 2010,

    cheers, Pete.

    Reply
  3. Pingback: The Workington Mediterranean Gull – an update | Birding Frontiers

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