2008 BAILIWICK OF GUERNSEY GULL PROJECT REPORT


 

Introduction

2008 saw the start of my specialist studies into gulls in the Bailiwick of Guernsey. The catalyst for this was an invitation from Jamie Hooper to take over the rest of his colour ring sequence from his decade long (1998-2007 inclusive) project on nesting Herring Gulls (Larus argentatus). At the time, I was most interested in Lesser Black-backed Gulls (Larus fuscus graellsii), as I had long been visiting the breeding colonies to ring pulli. I am intrigued by the migration of this species, and the fact that it is now widely reported that the British population is becoming less migratory with many more birds wintering in Britain in the past three or four decades.

 I am also very interested in the recent mixed fortunes for the Channel Islands Lesser Black-backed Gull colonies, and in particular the apparent rapid growth on Burhou off Alderney (the largest colony in the Channel Islands at around 1,000 pairs). I suspect that some of the birds have moved from Sark to Burhou, but have not (yet) been able to prove this.

Up until the end of 2007 I had metal-ringed 1,381 Lesser Black backed Gulls, and 39 of these have so far been recovered as follows:-

Channel Islands                10

England                                 4

France                                    8

Portugal                               17

However, colour ringing would give the opportunity for greater recovery rates and the ability to track the same bird at several times during its life – at its breeding and wintering sites, as well as on migration. 

The first problem was trying to source the necessary colour rings, as I started my project just when the normal supplier ceased manufacture of the Darvics. Fortunately Risto Juvaste in Finland came to my help and supplied very nice ring plates.

 As I had started to catch a few adult Lesser Black-backed Gulls in my garden in May, Jamie gave me his last few colour rings and on 24th May I fitted my first colour ring on an adult male Lesser Black-backed Gull (6S6). I regularly saw this bird on the west coast of Guernsey in September, before it travelled south and was seen in N W Spain by Juan Ma Dominguez Robledo in November– a cracking start to the project!

 As the year progressed I began to watch gulls far more closely than ever before. This in turn gave rise to many questions – some of which detailed colour ringing projects could help to answer. In particular I wanted to know how Guernsey’s landfill site at Chouet on the north coast of the island affects the gull populations not just on Guernsey, but also in Sark, Herm and Alderney. With landfill set to close (or become far more restricted) in the next 5-10 years we can expect some significant changes to our gull populations. There would therefore be no better time to begin recording better data than now.

As a result I have now expanded my research into both Herring Gulls and Great Black-backed Gulls, and although colour ringing on these species will not commence in earnest until 2009 I have spent many hours since August watching gulls and recording the colour rings.

 A very brief synopsis of the work in 2008 on the three gull species is given below.

 Lesser Black-backed Gull (Larus fuscus graellsii)

26 adult Lesser Black-backed Gulls were caught in my garden at Ty Coed, Vale Marais, Guernsey during May and June; of these 16 were fitted with colour rings.

The 2008 breeding season turned out to be very mixed – with moderate success on Sark and Herm, but a virtual complete breeding failure on the Channel Islands’ largest colony on Burhou. This was the first time I had ever seen this. 43 nestlings were ringed on Brecqhou Island off Sark, with a further two on Sark and only three on Burhou (along with four breeding adults).

A total of 68 colour rings was fitted during 2008 – a very considerable disappointment (especially when one considers that in some years we have ringed c 300 pulli Lesser Black-backed Gulls on Burhou alone!).

I am amazed at the reporting rates of colour-ringed gulls. With such a poor first season I did not expect much in the way of sightings…so I was thrilled when during the summer the first reports were coming back. The first record was one of the adults ringed in my garden seen bathing in Sark in June by Steve Rosser (where I suspect it was breeding). On 20th August the first sighting came in from NW Spain (courtesy of Antonio Gutierrez), to be followed the very next day by a second in the same area by Antonio.

The autumn was fascinating, for as several were being seen in NW Iberia, I was enjoying finding a few around Guernsey – with a couple of chicks from Brecqhou and also some of the adults I’d ringed in my garden during the breeding season. Looking for my birds I came across a couple of UK birds – one from Peter Stewart’s work at landfill sites in Gloucestershire and one of Peter Rock’s Bristol urban-born birds.

Just when I was convinced that at least one of the Brecqhou born birds (5.Z8) would winter with us here in Guernsey, it vanished. I last saw this bird on 21st October. In fact from weekly counts of L B B Gulls at two of the Island’s best sites (Chouet Landfill on the north coast and Perelle Bay on the west coast) I learnt that very few (if any) of the Channel Islands bred birds remain on Guernsey for the entire winter. From peak counts of several hundreds both sites went down to a maximum of 5-6 birds in late November/December.

In late November I received a very exciting report from Peter Rock who had just returned from the west coast of Portugal where he had seen no fewer than three of my birds (not bad out of a grand total of only 68 colour ringed!). Remarkably two of these birds had been seen earlier on passage in NW Spain. Another bird seen in Pontevedra, NW Spain by Antonio Cordeiro in October, was later seen at Portimao, Algarve, Portugal at the end of December by Tseard and Derick Hiemstra.

Finally there was also a thrilling report of another of the adult gulls ringed in my garden from Quarteira in the Algarve in the far south of Portugal from Michael Davis, and a sighting of another Brecqhou-born youngster at Malaga Port, Spain in mid December by Morten Helberg.

 Writing this at the close of the year I cannot wait for the 2009 season. There is so much to learn about our Lesser Black-backed Gulls. Hopefully next year I will be able to colour ring more of the breeding adults on their nesting grounds, as well as ringing chicks in the colonies. I also hope to continue my studies at the Bailiwick’s only landfill site.

 Herring Gull (Larus argentatus)

My interest with Herring Gulls really stemmed from all the hours I had spent searching for my colour ringed Lesser Black-backed Gulls. It did not take long, however, to realise how little I knew about a bird I have seen almost every single day of my life! Over the period 1998-2007 inclusive my good friend Jamie Hooper had colour ringed almost 2,000 pulli Herring Gulls.  I had seen several of them along the Guernsey coastline over the decade, but never really taken a great interest…even when I caught a few of the birds (during my metal-ringing operations).

In 2008 I got to know some of Jamie’s birds really well – seeing them virtually weekly. It was soon obvious to me that many of the assumptions I (and others) make about the feeding habits of these gulls, and the use they make of our landfill site, are not in fact correct. While some individual gulls are present at the site virtually daily, the majority visit far less frequently.Of Jamie’s 2,000 or so colour-ringed gulls, I managed to see 279 during 2008. Many were from the early years of his project, and I was surprised at how many of the birds I saw had never been reported before. A summary of the years of original ringing is as follows: -

 

1998   21        2003           33

1999   26        2004           36

2000   40        2005           44                                                                                    

2001   30        2006           23

2002   18        2007             8                                                    

 

In all I managed 1,084 successful ring reads of locally ringed Herring Gulls over the period August – December.

Jamie has yet to write up the results from his research, so I do not want to steal his thunder, but it is fascinating to see how many of the locally born gulls go wandering along the English Channel – mostly along the French coastline, with first year birds wintering as far south as Vendee. Other birds wander to the south coast of England and penetrate as far as the landfill sites around Gloucester.

I believe that the majority of Bailiwick-born Herring Gulls do in fact return to breed in the islands, although there are also records of locally born gulls nesting on the adjacent coasts of France.

My many hours of observation at the landfill site since August, and along Guernsey’s coastline, gave rich results with observations of locally ringed birds that had previously been seen out of the island as follows:

 

France                       15

England                     13

Germany                     1

Jersey                         6

 

So far I have also heard of two birds I recorded in Guernsey, which have subsequently travelled to the nearby French coasts.   

I was also thrilled to spot a French-ringed Herring Gull at the landfill site. This bird had been ringed in Calvados as a first year. It spent just over a month in Guernsey and has subsequently been seen again on the eastern side of the Cherbourg Peninsula. In addition I saw three Jersey colour-ringed birds in Guernsey.

With my interest in Herring Gulls growing by the week, a breakthrough occurred in the autumn when a local company (Creaseys) which holds the Marks & Spencer franchise decided to use the money charged to customers for plastic shopping bags to assist local environmental projects. The funds were given to La Societe Guernesiaise, who very kindly decided to use a significant part of the money to sponsor the cost of the colour rings so that I could expand  my existing Lesser Black-backed Gull colour-ringing project to include both Herring Gulls and Great Black-backed Gulls. 

I managed to colour ring 17 adult Herring Gulls in my garden, and a further four at Chouet landfill site in 2008. By the end of the year I had seen no fewer than 13 of these birds – some as many as 13 times. One of these adults was subsequently reported dead on the beach on Noirmoutier Island, Vendee, France at the end of October.

Through this very kind sponsorship I am now equipped to colour-ring all three species of gull breeding in the Bailiwick of Guernsey from 2009. I must also here acknowledge the help and support of Margaret and Rich Austin, who administer the Channel Islands Bird Ringing Scheme. Their approval to expand the colour-ringing programme is much appreciated. It will no doubt add significantly to their administrative responsibilities and their workload with the Scheme.

Great Black-backed Gull (Larus marinus)

Although we metal ringed 28 Great Black-backed Gull chicks during the summer, I was not at that stage anticipating getting more involved in working with this species. However, once I began to search the gull flocks at the landfill site from August onwards, I could not help but take more of an interest in our largest gull.

I saw quite a few metal-ringed birds at the landfill site, but only managed to read two of them; a bird ringed as a chick on Jethou and another ringed as a chick on Lihou both in the summer of 2006. I really wanted to know where these metal-ringed gulls had come from – especially when I began to see colour-ringed birds. During August – December I saw no fewer than twelve French-ringed Great Black-backed Gulls. There were six from the nearby Chausey Islands – all ringed by Sebastien Provost, five from Le Havre and one ringed on the roof of a nuclear power station on the coast of Seine-Maritime (all from a study by Gilles Le Guillou). One of the Le Havre birds had already been seen as far west down the English Channel as Ushant and as far east as Dungeness. Similarly one of the Chausey birds had already travelled to western Finistere and then returned to the Bay of St Malo, before being seen here in Guernsey. 

In addition I saw two birds from the colour-ringing project being run in Jersey by my friend Ian Buxton.

The icing on the cake for this species came in late November, when in the space of two days I saw two Norwegian-ringed birds – one from the far north-east and the other from the extreme south-west of the country. In fact the more distant bird had been ringed on the seabird island of Hornoya, off Vardo in Finnmark. I had had the good fortune to visit this island with my son Merlin in 2004 – some two years after the gull that visited Guernsey was ringed there. Before the end of the year I saw another Norwegian-ringed bird from an island just to the north of Stavanger. This bird had been ringed in the summer of 2007, and had already been seen at Dungeness, Kent, England.

I now have colour rings for this species and intend to commence this study during the 2009 breeding season.

Mediterranean Gull (Larus melanocephalus)

Although a scarce visitor to Guernsey with up to ten birds being seen at a time in the early autumn in Guernsey, it was a great excitement to see a bird that had been colour-ringed at its breeding colony in Belgium. In fact this bird had been reported in Guernsey in both of the previous autumns (late July/early August), and had even been seen in January 2007 at Carcavelos, Estremadura, Portugal.

Black-headed Gull (Larus ridibundus)

Despite careful checking of the birds during autumn and early winter no colour- ringed birds were observed. At least half a dozen metal-ringed birds (from foreign schemes) were seen. However, I failed to read any of them. Reading such small metal rings on such an active gull is a very difficult art!

Conclusion
Despite the poor breeding season for Lesser Black-backed Gulls in the Bailiwick, 2008 proved to be a very exciting year for my gull studies. I finished the year with many more questions than I had at the start, but am full of determination to study the three gull species to improve our knowledge and understanding of these birds in the Channel Islands.

I have elevated these studies to the very top of my bird ringing activities, and will be strongly focusing in the years ahead on colour ringing a good sample of gulls, as well as spending many hours in the field trying to build up good records of their activities.

My sincere thanks to all those who have helped me in this my first year, especially those gull enthusiasts who work so hard to discover and report colour ringed gulls.


Paul K Veron

Channel Islands Bird Ringing Permit No 129

 

 

31 December 2008