This article is mainly concerned with the patterns of occurrence which have been found out from observations of colour-ringed birds.   In this respect many of "our birds" have a history of previous sightings and we have also followed up subsequent reports of birds seen in this area.  We are very grateful to Peter Meininger, Renaud Flamant and Camille Duponcheel, the Polish and Czech ringing centres for prompt response to requests for information.   The other part of the article deals with changes of abundance over the years and seasonal patterns.

Dave Thexton recorded the first Mediterranean Gull in this area on the now "defunct" Silverdale Marsh in 1976.   No others until 1979, then another gap before 1-5 per year 1983-7, c7 in 1988, c6 in 1989.  Then there was a rapid increase, with 30-45 annually between 1992-1998 (some of these were on the Kent Estuary, outside the scope of this article).   There has been no obvious increase since the mid-1990s and indeed two factors have led to a slight recent decrease, especially in spring records.   This has been partially but not completely counterbalanced by an increase in autumn juveniles on Heysham outfalls.   These factors comprise a decline on Heysham outfalls due to disturbance by anglers and the timing of 'outages' (e.g. 2004).   This has led to a reduction in the 1^st summer Common Gull flock which has contained several Meds. in previous springs.  The other factor has been the disappearance of a sizeable gull colony on the Dockacres complex.  The Tewitfield pool colony used to be particularly favoured with up to 5 birds seen at one time and 7 in total during spring 1998.

The main occurrence patterns involve:  wintering birds; breeding or territorial birds; spring passage adult, followed by second then first summer birds; autumn post-breeding season gatherings, late summer records of juveniles.   Ringing recoveries have provided some useful information on the origin and subsequent movement of these birds.  

Example One

Wandering 1^st summers

First summer birds wandering north, sometimes in the company of Common Gulls are a feature.   These are then presumed to return south.  Good examples affecting our area are:

Green 27U
Ringed:  Zandvlietsuis, Antwerp, Belgium               Pullus            22/6/02
Read in field:  Great Yarmouth, Norfolk                                6/10-19/10/02
Read in field:  Eric Morecambe Pool, Leighton Moss                    5/5/03

White 7FJ
Ringed:  Stellendam, Zuid-Holland, Netherlands      Pullus           3/6/99
Read in field:  Borwick Waters (Dockacres)                            29/4 & 2/5/00
Read in field:  Boulogne, Pas de Calais, France                       27/6-19/7/00                              

Example Two

Juvenile dispersal

Three very different patterns.   The norm is for juveniles to remain for a few days before moving on and indeed 1^st winter birds are quite scarce in this area during the winter months.   The first recovery involves a much longer autumnal stay than is usual followed by a movement far to the south.  The second bird remained to winter in the Heysham area but departed in the spring.  The third spent a rather mobile first autumn between the Wyre, Heysham and Morecambe before settling to winter along Morecambe seafront.  Summering in the Allen Pool Black-headed Gull colony was followed by a second winter stay off Morecambe.  Then a brief return to the Allen Pool before presumably heading south to its natal area to hold territory?   The fourth represents a bird which became a multi-observed 'channel hopper' after being seen at Heysham

Green 09J
Ringed:  Zeebrugge, Belgium                                   Pullus   11/6/00
Read in field:  Heysham outfalls                                             31/7-1/10/00
Read in field:  Pontevedra, Spain                                           21/1/02
Czech Republic EX78711
Ringed:  Chomoutov, Olomoucky, Czech Republic   Pullus   3/6/03
Read in field intermittently:  Heysham outfalls/harbour          24/8/03-26/3/04

Green 36W
Ringed:  Zandvlietsuis, Belgium                               Pullus    9/6/02
Read in field:  Heysham Heliport                                           11/8/02
Read in field:  Skippool, Wyre Estuary                                  27/9/02
Intermittently read in field:  off Morecambe                            3/10/02-18/4/03
Read in field:  Eric Morecambe Pool                                        April-July 2003
Read in field:  off Morecambe (mainly Town Hall area)         August 2003-February 2004
Read in field:  Eric Morecambe pool area                              at least 8/3/04
Read in field:  Strathmore Hotel area during poor weather    9/3/04  

White 36A
Ringed:    Zeeland, Netherlands                                Pullus    5/6/90
Read in field:   Heysham outfalls                                             25-26/8/90
Plenty of subsequent sightings around Pas de Calais during 1991-2000, also:
Read in field:  Zeebrugge, Belgium                                         10-13/4/93
Read in field:  Swanage, Dorset                                              28/8/99
Then a belated hint of the wintering site = west Kerry, Ireland in 2003/4!

Example Three

The Polish liaison

This could only have been sorted out by ringing!   Ironically, an attempt was made to ring the wintering Morecambe bird in 1998 to see where it came from but it just eluded the "butterfly net".   Instead we had to wait for it to reappear in the 2003/4 winter bearing a Polish ring!    In the meantime, Pete Fletcher noted a Polish-ringed bird (P70) on the Battery car park in late January 2003.  This was subsequently seen to display to the resident wintering bird and they appeared to depart together.    In spring 2004, a "different" Polish bird (P96) appeared and began to display to the resident wintering bird.   This transpired to be a re-ring of  P70 (ring showing slight damage) and, yes, they were a breeding pair in Poland in 2003!   Note how they "gave each other space" during the winter before getting together ready for the breeding season - must have been reading trendy magazines!

White 5HR
Present:   Morecambe Town Hall foreshore           1^st summer    16/3-13/7/95
Present:   Heysham outfalls                                    1^st S/2^nd W    12/8-29/9/95
Present:   Morecambe Stone Jetty area                  2^nd W            October 1995-March 1996      
Present: Morecambe Stone Jetty area         late summer-spring 1996/7-2002/3
Ringed:  Skoki Duze, Wroclawek, Poland               adult male      15/5/03
Read in field:  Morecambe Stone jetty and area                            27/7/03-18/3/04  

P70/96
Ringed:   Skoki Duze, Wroclawek, Poland             adult female     19/5/01
Read in field:   off Morecambe intermittent                 30/1/03-mid March 2003
Retrapped & re-ringed    Skoki Duze                                               19/5/03
Read in field in company of 5HR: off Morecambe             8/3-9/3 & 18/3/04

The wanderings of the breeding adult at Leighton Moss (1997) has been well-documented so space precludes detail here. 

The map shows the origin of birds ringed as pulli or breeding adults which have occurred in this area.  Black-headed Gulls (which also breed in Holland etc) are also included to show that our birds are of much more northern origin than those breeding with the Mediterranean Gulls

Pete Marsh     

                                                 

1^st winter Med Gull 12.03.04