Colour Ringing Large Gulls

Grampian and Tay Ringing Group

2011-12 Report

Introduction

In August 2010, I discovered that Herring Gulls in Aberdeen were surprisingly easy to catch during summer. The first I caught by hand was eating bread placed on top of a car whilst I was inside. The bird was plucked from the roof through the window! The next day myself and Calum Campbell drove around the city using this method, and swiftly captured and ringed 20 Herring Gulls within a few hours. As the breeding season drew to an end the gulls became less hungry and easy to catch, but we were certainly inspired to put in a larger and more organised effort the following year.

Meanwhile in Montrose, Ben Herschell of Tay Ringing Group had been catching and metal ringing good numbers of Herring Gulls in his garden. Having received little recoveries, he suggested we join together with a colour ringing project, in an attempt to increase information from ringed birds.

The first gulls of the project were caught on 31st

May 2011, and since then 830 large gulls have been colour

ringed by Grampian and Tay Ringing Groups. Of these 672 are Herring Gulls, 141 Lesser Black-backed Gulls, 16

Greater Black-backed Gulls and 1 Glaucous Gull. The majority of these birds have been adults ringed during

summer, mostly in Aberdeen City, but also at Montrose, Peterhead, and Fraserburgh. We have also ringed

over 200 chicks, at Loch Leven , on the cliffs along the north Aberdeenshire coast, and a few in urban breeding

colonies in Aberdeen and Montrose.

So far we have had 420 sightings of 235 individuals, a 1 in 3.5 sighting rate. 60 individuals have been have

been sighted in countries outwith Scotland, consisting of England, Ireland, Norway, Denmark, Germany, The

Netherlands, France, Spain, Portugal and Morocco.

A typical visit to Asda during Gull catching season

Catching Methods

The main catching method for ringing large numbers of gulls is cannon netting, normally on landfill sites. However this is not a method we can use, as the North East no longer has any significant landfills with food waste, as well as having no licenced cannon netters willing to catch gulls! Therefore we have to use methods which mean catching fairly small numbers of birds at a time.

The best time of year to catch gulls is the breeding season. Starting in May when the birds begin to nest, and ending in August when the chicks have fledged, this period sees gulls at their most aggressive and confiding. The rest of the year, apart from in very cold weather, gulls will rarely come near to any traps and nets, or close enough to catch by hand. This cautiousness disappears almost entirely in summer, with the necessity to feed chicks far outweighing the potential danger of being trapped.

Perhaps half the gulls we have ringed have been caught using a whoosh net. A whoosh net consists of a net, normally no longer than 7 metres, laid on the ground with bait placed on front of it. It is fired over any birds in the area via poles, pulled by high tensioned elastic. Outwith the breeding season, gulls will go nowhere near a whoosh net unless snow is on the ground, however they will comfortably feed in front of one in summer. The maximum catch is normally 15 birds. The net can be set anywhere, however a site that is baited regularly, like a garden, is the most effective for birds to enter the catching area quickly. We have also used whoosh nets with a pole threaded through the leading edge placed on top of a wall. Bait is put at the base of the wall and the net is pulled over the birds.

The other main method we use is hand catching. When in a feeding frenzy, gulls are slow and clumsy to take off, so it possible to capture them by hand. Either putting bait in the corner of a fence where the gulls movement is restricted, or baiting behind a car or building where they don’t see you coming, are effective methods. Despite only normally catching 1 or 2 at a time (although 2 of us have caught 7 in one go against a fence), hand catching is quick and easy and in summer can be done almost anywhere there are urban breeding gulls present, so eventually totals built up. One downside is that hand catching is normally done in built up areas, so attention from bemused members of the public is commonplace.

Although meat and fish are the best, the most frequent and cheapest bait we use is bread. The gulls greed is easily stimulated, so the more bread thrown the more gulls will go down into the catching area. We have been through literally several hundreds of loafs of bread in the past year and a half!

When we’ve caught birds we normally try to measure the length of their total head and bill. This can determine whether they are male or female, with the male being larger. All Gulls are fitted with a standard BTO metal ring on the right leg, and on the left leg a yellow darvic ring with black lettering. All start with the letter T and a colon, followed by either 3 numbers or two numbers and a letter.

Herring Gulls caught in a whoosh net

Herring Gull

The top species we have ringed is the Herring Gull

and Aberdeen is our main catching area, with 450

birds being ringed here. The city has one of the

highest breeding populations of urban Herring

Gulls in Britain; with over 3500 pairs in 2002 (a

new survey is definitely overdue however as

numbers are almost certainly less now). The

majority of birds ringed in the city are adults. One

of the main catching sites is my garden in

Peterculter, a suburb 8 miles from the city centre.

130 gulls have been ringed here. Other sites are

spread out across the city. You can pretty much

catch Herring Gulls almost anywhere in

Aberdeen during summer!

Gull numbers in Aberdeen are at their peak during summer and after the breeding season numbers drop

significantly. We get very little sightings in autumn, when birds are presumably feeding in fields and therefore

not being looked at by birdwatchers. But come the winter months we get a lot more reports, as gulls move to

estuaries, landfill sites and urban areas, where they are more likely to be spotted.

As well as numerous local sightings, we have had Aberdeen ringed Herring Gulls have been seen all over

Britain during winter. In Scotland we have had sightings from Glasgow, Lothian, Angus and the Borders, and

from England we’ve had birds in Durham, Newcastle, Leicestershire, Manchester, Cheshire, Lincolnshire,

Norfolk, and Yorkshire. We have had one bird returning to exactly the same site two winters in a row. Ringed

as a third summer on July 15th

2011, T:090 was seen at Shawell refuse tip, Leicestershire on 26th

January 2012,

and was back again on 1st

December.

We’ve also had some gulls seen overseas. Four individuals were seen at Dannes landfill site in Northern France

during December 2012. One of these birds, T:228, was notable as it had been sighted only 15km up the coast

at Boulogne Sur Mer the previous winter on 15th

December 2011. Again this suggests gulls are faithful to their

wintering site. Another foreign movement came from

Herring Gull T:101, ringed on 22nd

July 2011 at West

Tullos Industrial Estate. It was next seen at Ouddorp, the

Netherlands on 16th

January 2012. We then sighted it

back at West Tullos the following summer on 23rd

July,

on a rooftop along with two chicks. This is the first

confirmed breeding gull we know of going abroad and

returning the next year.

The harbours of Peterhead and Fraserburgh hold good

numbers of gulls throughout the year. A few visits have

resulted in 35 Herring Gulls ringed in Peterhead, and 23

in Fraserburgh. A few of these birds were ringed in

winter, including a strikingly pale first winter Herring

Gull, ringed T:610 at Peterhead on 8th

January 2012. We

assumed this bird was from the Scandinavian

subspecies, which was confirmed when it was seen at

Ferkingstad, Norway on 14th

March. Another Peterhead

T:610 at Ferkingstad, Norway (Arnt Kvinnesland)

T:433 at Dannes Landfill, France (Harry Vercuijsse)

Herring Gull, this time an adult ringed in summer on 3rd

August 2011, was seen at Dublin Ireland on 31st

December 2012. Another bird ringed the same day, this time a juvenile, was seen several times during

December 2012 at Gunknowe Loch, Galashiels. Apart from these long distance movements, local sightings

from the harbours suggest most of the gulls ringed in summer remain there all year round. Surprisingly we

have not had any gulls ringed in Peterhead seen in Fraserburgh and vice versa, despite their close proximity.

Winnyfold and Bullers of Buchan are large seabird colonies between Peterhead and Aberdeen with good

numbers of cliff nesting Herring Gull. We hadn’t ringed any costal chicks in 2011, but decided to do some the

following year. Unfortunately abysmal weather meant the gulls had a relatively poor breeding season, but we

still managed to colour ring 47 chicks at Winnyfold and 13 at Bullers. Since ringing we have had several

sightings around the coast of Aberdeenshire, as well as one longer distance movement, a bird seen at

Gunknowe Loch, Galashiels in December 2012.

Montrose has a high breeding population of Herring Gulls nesting in the town, and 83 have been ringed so far.

As well as some local sightings, we have had several long distance winter movements from Montrose birds. A

notable sighting was a bird ringed as a juvenile seen at a landfill site in Lincolnshire on 23rd January 2012, and

then on a beach in Norfolk on 25th March. We have had also had sightings of birds from Yorkshire, Essex, and

Chesire

27 Herring Gull chicks were ringed at the primarily Lesser Black-backed Gull colony on St. Serf’s Island, Loch

Leven in July 2012. We have two sightings from them so far; one was seen at Hogganfield Loch, Glasgow on

29th

September and one at Richmond Bank, Cheshire on 13th

November.

Winter movements of Herring Gulls ringed in North-East Scotland

Long distance winter sightings of Herring Gulls ringed in North East Scotland

Lesser Black backed Gull

141 Lesser Black-backed Gulls have

been ringed so far, with the majority

being chicks at the colony on St.

Serf’s Island, Loch Leven.

The colony consists of over 1000

pairs, mainly LBBG but with a few

Herring and GBBG also. Chicks had

been metal ringed by Tay Ringing

Group for several years, with little

results. Although poor weather

meant there were only a few chances

for ringing, we managed two visits in

July 2012, in which 151 chicks were

colour ringed, 126 of which were

LBBG.

The first few months after ringing we heard little about any ringed birds. The only report from this time was a

dead bird found headless atop a cliff in Devon on 10th

August! However, from September we started to get a

good number of sightings from warmer climates. So far we have had 50 foreign sightings of 24 individuals. We

have had 14 seen in Portugal, 7 in Spain and 5 in Morocco. We have also had movements between countries.

Two birds seen in the north of Spain were later sighted a few weeks later in Portugal, as well as a bird first seen

in Portugal sighted a month later in Adigar, Morocco. The furthest movement of any bird was T:61C, seen at

Dakhla in the Western Sahara on 17th

December, having travelled a distance of 3767 km. Not all chicks from

the colony have gone so far south though. T:11C was seen in Wexford in South-east Ireland on 08th

January

2013, the only St. Serf’s LBBG chick we know of to have remained in the British Isles.

Only 9 Lesser Black-backed Gulls have

been colour ringed in Aberdeen during

summer, but we’ve still had some

interesting sightings from them. Adult

LBBG T:027, ringed at Aberdeen beach

on 26th

June 2011, was seen from 5th

September, 2011, to 23rd

February,

2012, at El Puerto De Santa Maria,

Spain. It was not seen at all during the

summer, but was sighted again in Spain

on 26th

September at Isla Cristina,

120km from its original winter site.

However it was back at El Puerto De

Santa Maria by 20th

December, showing

that adult LBBG will return to exactly

the same location in winter.

T:11A at Chipiona, Spain (Rafa Garica)

Ringing LBBG chicks on St. Serf’s Island

T:027 at El Puerto De Santa Maria, Spain (Rafa Garica)

Another adult LBBG, T:300 ringed at

Peterculter on 12th

June 2012, was sighed at

Albion Landfill Site, Leicestershire on 11th

November. At this time we had many

sightings of birds in Spain and Portugal, but

this bird had interestingly remained in

Britain, reflecting the ever growing

wintering population of this species in

England.

Few LBBG have also been colour ringed in

Montrose also, only 6 birds. However one

has still been seen abroad, a bird ringed as a

chick on 22nd

July 2012 sighted at

Matosinhos, Portugal on 7th

December. This

shows how relatively few birds can still

provide information on foreign movements

thanks to colour rings.

Winter sightings of LBBGU in the Mediterranean

T:006 at Hirsthals, Denmark (Lars Pederson)

Greater Black-backed Gull

Only 16 Greater Black-backed Gulls have been colour ringed in the project so far. Apart from 3 chicks at

Winnyfold, all have been ringed as fully grown birds at Peterhead and Fraserburgh. Despite the small number

of birds ringed, we still have had some interesting sightings

On 26th

December, 2011, we attempted to

catch some GBBG at Peterhead Harbour.

Unfortunately the net misfired, and only 3 first

winter birds were caught. However, we

discovered soon after that one of them, T:007,

was seen at St. Peter Ording, Germany, on 30th

December , only four days after ringing. We

continued to receive sightings from this bird in

the same location throughout the following

year, with the last being in August. Later on in

the year we discovered that the other two

birds from the catch had also been sighted

abroad. T:005 was seen at Hanstholm,

Denmark on 13th

May, and T:006 at Hirtshals,

Denmark on 26th

June.

All 3 gulls were sighted in harbour towns, suggesting they had simply followed boats across the North Sea. A

100% foreign resighting rate out of only 3 birds is a tremendous return, and shows the value of colour rings on

GBBG. We have also had 8 individual GBBG sighted locally, again showing how high the resighting rate is for

this species. Although we do not have the large numbers of breeding birds found on the western and northen

coasts of Scotland, we do occasionally have significant numbers present in the harbours during winter, so

hopefully we will be able to ring a good few more in the future.

Movements of 3 GBBG ringed on the same day

Glaucous Gull

In 2011, a second summer Glaucous Gull was present at the Ugie

Estuary, Peterhead from the middle of July, a rather unusual time

for this species. On the 3rd

August, during a successful day in which

40 gulls were ringed at Fraserburgh and Peterhead, we stopped by

the Ugie, where we discovered the Glaucous Gull was coming in

fairly close to bread. A lucky dive at it and the bird was captured

and colour ringed T:193. Apart from a sighting in the same location

by local birders a few hours later, the bird promptly disappeared. A

Glaucous Gull matching the age of the bird was seen in a field

nearby the following month, but its legs were not seen to confirm it

was ringed.

It was not until the 23rd

December we heard of T:193 again. It was

seen by two separate observers at Boldon Flats Tyne and Wear. It

was then sighted at Seaton Carew on 15th

January, and then

disappeared for a month, until it was spotted at Cotham Landfill

site, Nottinghamshire on 18th

February. It was sighted by several

observers there, with the last sighting being the 27th

. It was found again on 8th

March at the nearby Ogston

Reservoir, Derbyshire, where it stayed for a few days. The bird then went north again, and was seen at

Longnewton Reservoir, Cleveland on 24th

March. The sightings that followed were all fairly close together,

Lingham Lake on 3rd

April and Langwith House on 7th

, both in Yorkshire. The last known location of T:193 was

at Scorton Quarry Yorkshire on 25th

April.

This bird has the most sightings of any gull in our project, 8 different locations since ringing with 13 different

observers. The reason behind this is undoubtedly because it is a large, pale and sought after by birdwatchers.

Whether other gull species we have ringed move around so frequently during winter remains to be seen.

Although the Glaucous Gull is a fairly regular winter visitor to the coasts of Britain, with over 100 normally seen

every year, this bird was only the 62nd

ever ringed. There are only a few Glaucous Gull recoveries, all from dead

birds, therefore these sightings are unique in showing the winter movements of this species in the UK.

Movements of T:193 between 03/08/11 and 24/04/2012 T:193 at Scorton Quarry (Steve Clifton)

Conclusion

One thing the project has demonstrated so far is the effectiveness of using colour rings on large gulls for

obtaining sightings. If we had only used metal rings for this project, we would only have a meagre 2 recoveries

so far from dead birds, as opposed to hundreds of sightings of live individuals which are vastly more valuable.

The project has shown how mobile large gulls in Eastern Scotland are. Herring Gulls we’ve ringed during the

breeding season can travel surprisingly far in winter, as south as France and the Netherlands. Despite these

long distance movements, some birds remain in the same area all year round, scarcely moving at all. The

Lesser Black-backed Gulls we have ringed have wintered from England to the Sahara. The sightings from birds

in the Mediterranean and beyond are valuable, but the birds that remain in the British Isles are just as

interesting. Continued ringing will hopefully show if this trend increases in years to come.

Aberdeen City has a nationally important breeding population of Herring Gulls, and one of the next stages for

the project is to attempt a breeding bird survey, the last one being over 10 years ago. Amidst public calls for

culls on gull numbers, and the fact that the Herring Gull has suffered a major overall decline in recent years to

the extent it is now a Red Listed species, now is a good time to undertake this. This will also give an

opportunity to sight colour ringed birds in their breeding grounds.

Another aspect that could be looked at is where birds ringed as chicks breed and winter. Do urban chicks and

coastal chicks return to breed in the same habitat and do they winter in different locations? This could be

particularly interesting as the coastal breeding population has suffered a severe collapse in recent years. To

achieve this a lot more chicks are going to have to be ringed, as at the moment adult birds make up the

majority of our total. Another aim is to catch more gulls in winter, as currently the vast majority have been

ringed in the breeding season. Unfortunately the lack of cold weather the past few years has hindered this.

Thank you to everybody involved in this project. Thank you to the ringers from Grampian and Tay Ringing

Groups that have helped out, particularly Calum Campbell, Raymond Duncan, Ben Herschell and Neil Mitchell.

Thank you to Pete Rock for coordinating the colour ring codes and forwarding on sightings. Thank you to the

Scottish Ornithologists Club for their Endowment Fund Research Grant which helped to cover some of the

projects costs. And of course, a huge thank you to the many observers from numerous countries who have

tirelessly sent in sightings and photographs.

Euan Ferguson