Nar Valley Ornithological Society

Mediterranean Gulls at Great Yarmouth

Mediterranean Gulls breed almost entirely in Europe. It used to be that their stronghold was in the southeast with a remarkable 90% of the total breeding population occurring in countries bordering the Black Sea. However, during recent decades, there has been a marked shift to the northwest, with increasing populations in France, the Low Countries and the UK.

Without doubt the best place in Norfolk to see wintering Mediterranean Gulls ‘close up’ is the beach at Great Yarmouth between the Wellington and Britannia Piers. A visiting birder might expect to see up to fifty birds there.

Since 1999, a small number of NarVOS members, together with colleagues from the Wensum Valley Bird Society (WVBS), have regularly travelled to Great Yarmouth to read colour-rings on the Mediterranean Gulls that winter there.

To enable observers to read ring numbers, the birds on the beach can easily be attracted by throwing them a few scraps of bread. Timing is, however, important with an early arrival beneficial because nobody else will have fed the birds and they will be hungrier and thus easily attracted. The European bird ringing schemes have a colour-ringing project for Mediterranean Gulls. The rings, one per bird come in a variety of colours and are inscribed with (usually) a four letter and/or number code. They can be read from a distance with the aid of telescope. The rings are plastic and do not have an indefinite life, so each marked bird will have a colour-ring on one leg and a standard small metal ring on the other. When the light was good we were sometimes able to read the metal rings when no colour-ring was present.

Details of visits made in the winter of 2009/10, when 83 sightings of 21 individual colour-ringed birds from six countries were recorded, were published in the Norfolk Bird & Mammal Report 2009: The Origins of Great Yarmouth’s Mediterranean Gulls.

An ongoing project

The project has continued with monthly visits being made where possible during the period from late summer until the end of winter. Our first birds are on site from about mid-July and most are gone by mid-March.

When attracting the birds with pieces of bread, Tesco ‘value’ white is preferable - it stands out against the yellow sand, whereas brown bread is not only more expensive, the gulls surprisingly find it difficult to locate against a similarly coloured background. We have identified over 100 different Mediterranean Gulls that were ringed in 10 different countries. They have originated from Belgium, Germany, France, Poland, U.K., The Netherlands, Denmark, Czech Republic, Hungary and Serbia. There have been multiple sightings of many of these gulls and many valuable life histories have been identified, with some of the birds above having also visited Spain, Portugal and The Azores.

Project goes with a ‘bang’

The British Trust for Ornithology (BTO), impressed with the results, suggested that we should have a ‘joint venture’ to try and cannon net some of these birds and fit them with British colour-rings. Very few Mediterranean Gulls are ringed in Britain so this was seen as a challenge! Our aim was to add to the pool of ringed birds at Great Yarmouth and to further understand where these wintering birds originated. Maybe British breeding birds are there – we just didn’t know.

There was much preparation prior to the big day in November 2013. Pre-baiting was done for four days previously and the ‘team’ we met on site at 6am on Friday 8th November more in hope than anticipation! As well as the NarVOS members involved on the day there were also BTO staff and a handful of other ringers.

Preparing the site took about three quarters of an hour. It is well known that the average Mediterranean Gull is more intelligent than the average person trying to catch it! Accordingly we had to dig a trench in which to hide the net and then bury the cannons that were going to fire the net over the birds. That light and fluffy seaweed (not sure what it’s called) was then spread over all the exposed works, but confidence was still not high. Finally the electrics were all hitched up and we were ready to go. It was now a little before 7am. (the picture shows the holes being dug in which we buried the cannons).

But where were the gulls? Clearly we had been watched and they had viewed our activities with deep suspicion. We tried dispensing bread very sparingly to attract the birds towards the net where we had baited liberally, but they were having none of it. Incidentally the main bait had been thoroughly soaked so that the birds couldn’t take a lump of it away – if they wanted a good feed they would have to linger.

Nearly two hours later and we were still waiting. A Carrion Crow had been down to feed but we had little interest in it, unless of course it gave the gulls confidence to feed – which it didn’t. What little optimism there had been earlier was rapidly evaporating. Then at last a breakthrough – a group of gulls arrived, including some Meds, and started feeding. Anxious moments! Do we fire or wait for more? We made the right decision and fired. Boom!!! The explosives detonated and Yarmouth was awakened. Fortunately, we had alerted the local Constabulary so that they could fend off the complaints that were sure to come. A man from the Borough Council even turned up to keep an eye on us.

The net flew out and we had a catch! Elation all round, and talk of a celebratory bacon sandwich was rife. Firstly however, the birds had to be removed from the net. This was done speedily and we settled down to ring the birds. The plan was to put a metal ring on one leg (inscribed ‘Inform British Museum London’ along with a unique serial number. On the other leg was to be a plastic yellow ring with a combination of four letters/numbers that could be read through binoculars. This increases the reporting rate dramatically. Incidentally yellow is the colour allocated to the British and Irish Ringing Scheme.

The catch was a good one; 20 birds of which 13 were Mediterranean Gulls. To add to the excitement 3 of the Meds were already carrying rings – all of Belgian origin. The other 7 birds were 5 Black-headed Gulls, one Herring Gull and that Carrion Crow. The birds were ringed, measured and weighed before being released. The picture shows all age classes. From left to right there is a first-winter, a second-winter and a third (or older) winter. Hopefully those colour-rings would help us understand where all these birds were coming from.

Now it really was time for that bacon buttie. Somebody mentioned that it was right for the team to “bask in its own magnificence”. Modesty was forgotten as nobody disagreed.

Confidence was now sky high so we decided to try for another firing. Again it was a long wait but at 12.15pm we fired again. This time we caught another 5 Mediterranean Gulls plus another 5 Black-headed Gulls. Again they were duly processed so all that was left was for us to clear up and go our separate ways after an extremely satisfactory day. Further canon netting sessions were to be organised alongside our ring-reading visits.

Clearly, Great Yarmouth’s wintering Mediterranean Gulls come from far and wide. Previous years have seen birds reach Norfolk from all across Europe and as the Continent’s population continues to increase and expand, it seems certain that more fascinating observations will be made.

After 3 Winter's efforts, we had colour-ringed 46 Mediterranean Gulls. By now the birds had become much harder to catch, proving yet again that the average gull was more intelligent than the people trying to catch it. Now all we could do was to wait for sightings of the ringed birds to come in.

Where did they go?

Up to the end of 2020 a remarkable total of 1,114 reports of our 46 birds had been received, with the most-seen bird being sighted on 61 occasions. In addition to the U.K., reports came in from Belgium, The Netherlands, France and Germany. However, the ‘star of the show’ was a bird that was sighted at Minsk Rubbish Tip in Belarus. This was the first Belorussian recovery of a British-ringed Mediterranean Gull as well as being the furthest east report. Not only that, but the bird appeared to be paired up with another colour-ringed bird that had been ringed in Poland. We were even sent a photograph of the two birds together at the tip.

Sightings of our birds continue to be received, and are likely to continue for several years yet, since at least 26 of our ringed birds are still alive, having been seen during the second half of 2020. Who knows what is still to come from our efforts at Great Yarmouth?