Tuesday, 9 December 2014

Sorry about Knot blogging recently…

This week we received word of two Knot ring recoveries from the BTO. These birds were found dead at two separate locations on islands in the Wadden Sea on the northwest coast of Germany.

Wadden Sea Wikipedia

The Wadden Sea spans from The Netherlands along the coast of Germany and to the western half of the Danish coast. It’s an area well known to ornithologists as many species of waders, geese and ducks winter there, or use it as a re-fuelling or moulting area on their migration. 

The birds were cannon-netted and ringed on 30th January, 2014 at the Merrion Gate Spit on Sandymount Strand in Dublin Bay. 

Ringing (blue) and recovery (yellow) locations for the two Knots

The first bird (ST40506) was found on 24th July on the island of Helgoland, a total of 932 km from Dublin Bay. Helgoland is well known for its bird observatory and gives its name to a style of bird trap used to catch birds for ringing. The island is in the middle of a major migratory thoroughfare, so is superbly well placed for studying bird movements. 

The second bird (ST40507) was recovered on 12th August, 962 km from Dublin, at Sylt Island just off the German coast. This sandy island, connected to the mainland by a causeway, supports thousands of waterbirds each winter. 

Sylt Island, Wadden Sea, Germany Wikipedia

As both birds were described as “long dead” by the finders, it is most likely that these individuals perished on their way to their breeding grounds. They were most likely fuelling up in the Wadden Sea before making a two-step journey to their breeding grounds in Greenland and High Arctic Canada. 

Knot in breeding plumage during spring staging
in northwest Iceland
Jan van de Kam

From previous ring recoveries and re-sightings of colour-ringed birds, we know that the Knots in Dublin take alternate routes to their breeding grounds; some stopover in Norway and others stopover in Iceland. We’re delighted to get information on ring recoveries like these as they allow us to shed more light this intriguing situation.

Thursday, 23 October 2014

Time for thermals, the Brent Geese are back!

The Brent Geese have arrived, so there is no denying winter is well and truly here. During a count on October 17th, the Irish Brent Goose Research Group (IBGRG) had a tally of 23,500 at Strangford Lough, which accounts for a substantial proportion of the East Canadian High Arctic population. Most of the birds tend to stage in Strangford before filtering down to the rest of the country, and we tend to get about four of five thousand in Dublin each winter. 

Light-bellied Brent Flock IBGRG

We had about 40,000 birds across the country when they were surveyed last, in 2012, and as this accounts for such a large part of the flyway population, it means they are an important conservation priority for us. All our eggs in one basket and all that…

Sorry about that. Anyway...this year the first arrivals were right on cue, with birds being reported at Kincasslagh, Co. Donegal on September 5th. The first local record came two days later when, Cian Merne reported two birds at Bull Island on the 7th.

Dublin’s Brent Geese have adapted to sharing Dublin Bay with the 1.3 million inhabitants of our capital. They are attracted to the expansive intertidal mud flats, where the gorge on their preferred food, Zostera (Eelgrass). Once the Zostera has all been nibbled away, they switch to green algae or else make a move to recreational grasslands around the coast. So, later on in the season, they can be found well inland, on pitches and parks right across the city.

Brent flock feeding in McAuley Park, Dublin IBGRG

Brent Geese have for many years been the subject of an intensive marking study carried out by the IBGRG. In any given group you may spot colour-ringed birds, which are often easily readable with binoculars. All re-sightings should be reported to grahammcelwaine@btinternet.com , but keep a weather eye out for birds with red and blue rings. These birds will have been ringed on their breeding grounds in High Arctic Canada! Some of the research group spent the summer catching geese up there and have some amazing stories to tell.

So, make sure to wrap up, grab your binoculars and get out and have a look around your local patch for all the new winter arrivals.

For more info on these little geese check out the excellent IrishBrent Goose Research Group Blog

Tuesday, 23 September 2014

Familiar Faces

As the Dublin Bay Birds Project approaches its second winter, we are getting reacquainted with our colour-ringed waders. As well as getting to know the individuals, their haunts and habits in Dublin Bay, we are also beginning to see the real benefit of our ringing efforts. Our birds have been reported from as far away as Scotland, Iceland and Norway.

Bird ringing is not a new technique by any means, but it is a hugely effective tool in the conservationist’s tool kit. Not only does it allow us to build a picture of bird movements locally and internationally, but when we catch (or re-catch) birds, it allows us to collect biometric data and assess their body condition, which aids our understanding of the species, and ultimately leads to more effective conservation.

While colour-ringing (and subsequent re-sightings) generate valuable data, we are also fitting a subset of the birds with radio-transmitters in order to get a finer level of detail. The first of the radio-transmitters were deployed last January , and a mammoth radio-tracking effort followed. We collected some high resolution data on eleven radio-tagged birds, both by day and by night, during high and low tides.

 Radio-tracking continued into the spring, and by early April, we could no longer pick up the signals from any of the Oystercatchers or Bar-Tailed Godwits. The last of the Redshanks stuck around until the last week in April, before heading north into the unknown. 

Helen and Niall Radio tracking last winter

Out of sight, but never out of mind, we focused on terns for the summer months. But the colour-ringed and radio-tagged birds were never far from our minds: where were they breeding; had a winter feeding on Sandymount Strand allowed them to get into breeding condition; did they breed successfully; when would they arrive back in Dublin again?

Oystercatcher re-sighting locations (red)
Oystercatchers ringed as Pulli in Scotland and colour ringed in Dublin (green)
Ringing location (blue)

We checked emails eagerly, waiting for news from birders and researchers from far away with unpronounceable names. With time, the emails trickled in from far off places…

Among the jet setters were Redshank "BH", who was re-sighted in Iceland’s western fjords  on the 18th May, and Bar-tailed Godwit “DH", who was re-sighted in Finnmark, Norway a day later, on May 19th. Oystercatcher “CU” was seen (on a traffic island!) in Stokksetri in Iceland. His mate was subsequently colour-ringed as part of an Icelandic study. Who knows where she will spend the winter?

Redshank "BH" (yellow), Bar-Tailed Godwit "DH" (green) re-sighting locations
Ringing location (blue)

The database has almost reached 1,000 re-sightings, which is fantastic, and we’d like to sincerely thank everyone who has submitted records to date. These re-sightings are the life-blood of the project.
Of the 151 Oystercatchers that we ringed, 89% have been re-sighted at least once, and 66% of have been seen three times or more. Ten of them have been seen outside Ireland. Oystercatcher “FI" has been re-sighted in Dublin 23 times, and takes the crown for most regularly recorded colour-ringed bird. "FU" and "BC" come in at a close second, with 21 re-sightings each.

Redshank "AN" ringed and radio tagged John Fox

We were delighted to catch up with Oystercatchers, "NA" and "CH," and Redshanks, "AN" and "AP" in recent weeks. These guys have played a pivotal role in our data collection, as they carried radio-transmitters for us last winter. Great to see them back in Dublin again!

We are looking forward to the coming months and getting out and re-sighting more and more of our birds. We will continue to build a picture of their movements both within the bay and further afield. As always, we would love to hear from you and integrate your re-sightings into our growing database. It’s a great way to spend an autumnal day, and anyone can do it (but a scope or camera helps). If you do manage to get out and about, you can submit your sightings here.

Monday, 1 September 2014

Sandymount Spectacle

Annually, from mid-August onwards, Dublin Bay plays host to the avian spectacle that is the post-breeding tern aggregations. Sandymount Strand is a roosting hotspot for thousands of terns from four species. Common, Arctic and Roseate Terns make up the bulk, with Common Terns accounting for the vast majority. Most evenings, Sandwich Terns can also be observed too: you may not manage to pick one out from the crowd, but you'll most likely hear the loud grating kerrick kerrick calls of Sambos (to give them their cool name!) in flight. 

Sandwich Tern in breeding plumage Dick Coombes

It's not just birds that have bred in Dublin that are attracted to the Strand, but birds from the UK and further afield too. The fact that a small number of Black Terns, whose nearest breeding colony is in The Netherlands, are seen in the roost every year confirms that it's not just local birds that the roost supports. 

Mixed tern flock on Sandymount Strand John Fox

Dublin Bay provides an excellent food resource, in the form of small fish, in order to sustain the big numbers during this staging period. After feeding off-shore all day, the terns converge on Sandymount Strand in their thousands each evening. The numbers at the roost builds from mid-August to mid-September, until Mother Nature prompts them to set off southwards to spend the winter in west African waters, and even further to Antarctica, in the case of many of the Arctic Terns. 

Arctic Tern in breeding plumage Andrew Kelly

To avoid predation and disturbance, most terns tend to breed in out of reach places, such as off-shore islands, so this post-breeding aggregation offers a great chance to observe these beautifully delicate seabirds up close. The sheer numbers allow a fantastic opportunity to really appreciate these birds and to work on your ID skills! The best time to watch this spectacle is about an hour or so before sunset; and the higher tide the better, as the birds are pushed further up the beach.

Several roost censuses during this period allow us to determine the peak numbers and the species composition, and gives us an opportunity to assess the trends from year to year. So, if you see a couple of windswept guys staring in the direction of a large group of terns in the coming weeks, it's probably the Dublin Bay Birds Project team. Come say hello - we'd be happy to point out what's about and hear about what you've seen. 

Friday, 15 August 2014

Changing of the Guard

It's all change in Dublin Bay as the tern season comes to a close and the first good numbers of waders return south from breeding grounds in colder northern climes. The first returning waders tend to be non/failed breeders, followed by successful breeding birds and juveniles. The terns have raised their chicks (or failed, to as may be the case), and are now preparing to migrate south in the coming weeks.

It's been a reasonably good year for the Dublin Port terns with more Common and Arctic Tern nests than in 2013. Mild conditions and few extreme weather events will have helped their cause this year. Predation (probably by corvids) had some negative impact in the early season, but seemed to resolve when the full complement of adult Common Terns returned to breed and protect the colony. A nest count, on June 18th, gave 487 and 96 Common and Arctics, respectively. On the 11th June last year, there were 418 and 25 Common and Arctic tern nests.  

Common Tern chicks with some new jewelry Helen Boland

The terns will now begin to gather en masse in large mixed flocks across Dublin Bay in the coming weeks, with numbers peaking in mid-September. They will then trickle south, where many will winter along the West African coast.

On any given evening in September you will be able to witness up the terns roosting on Sandymount Strand. These species include Common Terns in very high numbers, good numbers of Arctic and Roseate Terns and handfuls of Sandwich Terns. You might also be lucky enough to to bag yourself a sighting of a Black Tern, which are annual visitors to Dublin Bay, en route from breeding colonies on the Continent. Our Little Terns leave directly after breeding and are rare in post-breeding flocks.

Post-breeding flock on Sandymount Strand Dick Coombes

As the tern numbers build, they are joined by waders that have bred further afield, and also by some scarcer visitors. Wood Sandpipers, Little Stints and Little Ringed Plovers are a few examples.

Our common wintering wader species will now begin to grow in number with flocks of Redshank, Oystercatcher and Bar-tailed Godwits getting larger by the day. Many of these birds will spend the winter here with a host of other waders, waterfowl and gulls. One such bird, Oystercatcher "BU," has already made his way home for the winter after being seen in Lossiemouth Estuary, Moray, NE Scotland on July 17th and again in Dublin at Merrion Gates Spit on July 30th.

Home to roost - "BU"s journey from Scotland

As always keep an eye out for colour ringed birds and we would be delighted to get your sightings reported. If you read any rings do report them to us here.

Friday, 27 June 2014

It's all turned terns at Dublin Port

On our last blog earlier in the month we were discussing colour-ringed wader re-sightings, but now the tern season is upon us, and its time to update you on the breeding terns in Dublin Port.

The annual breeding season monitoring started earlier this month, and the nest census revealed healthy numbers at the two subcolonies on the mooring dolphins in the port. We've made a few visits so far in order to count the nests and work out clutch sizes.

Common Tern colony on the ESB "Dolphin" in Dublin Port Helen Boland

Our first visit was all about nests and clutch sizes, and we recorded a total of 417 Common Tern and 66 Arctic Tern nests. Censusing the platforms is quite straightforward pre-hatching, as you're not trying to count mobile chicks, scurrying into the tiniest of gaps! During the visit we encountered a number of predated eggs, which, like last year, look like corvid depredation. The tern eggs had been snatched, brought to a safe (from mobbing terns) spot, and eaten by the culprit. It's a fairly natural occurrence in the early part of the season, and as tern numbers build, so does their capacity to deal with intruders.

Corvid predated Common Tern egg Richard Nairn

When rowing out to the colony, we saw a small number of adult Common Terns "belly dipping" in the water in an effort to dowse the eggs to keep them cool in the strong June sunshine. This is a behavior often exhibited by tropical tern species, such as White-cheeked and Whiskered Terns in warmer climes, as the eggs can over-heat and the chicks more or less cook inside the shell! People often think that when a bird is sitting on the nest that the sole purpose is to keep them warm, but in fact it can often be done to shelter the eggs or nestlings from overheating.

Arctic Terns will nest anywhere. Richard Nairn

Our second visit revealed an increase in nest numbers: 487 and 91, Common and Arctic Terns, respectively. A total of 315 chicks, 42 of which were Arctic Terns, were ringed. We counted 555 Common and 58 Arctic Tern chicks, but there were still some eggs, which will hatch over the next few days.

Common Tern chicks, ready to be ringed. Helen Boland

All in all, its turning out to be a reasonable year for the port terns. Mean clutch size is on par with their Rockabill peers.

We will continue to monitor the fortunes of the colony and report back soon on progress.


Tuesday, 10 June 2014

Bar-tailed Godwit, DH, enjoys some midnight sun

Just a very quick one today, to mention our first Bar-tailed Godwit re-sighting outside Ireland. It turns out that this is also the furthest away that we’ve had a re-sighting!

Ringing and re-sighting locations for Bar-tailed Godwit, DH. 

While we managed to catch up with, and ring-read, 31 out of the 99 Bar-tailed Godwits (ringed 31st Jan, 2014) before they left Dublin Bay, DH wasn’t read until the 18th May, when it was photographed by Tomas Aarvak. Here’s a very dapper-looking DH in northern Norway, looking a lot more colourful than on the ringing day in January.

Bar-tailed Godwit, DH, in breeding plumage in Porsanger, 
Finnmark, Norway on 18th May, 2014. Tomas Aarvak 

It won’t be long now before we start to see waders, most likely failed breeders, returning from the north, and there are also quite a few of the colour-ringed Oystercatchers and Bar-tailed Godwits summering in Dublin. So, if you feel like getting out there to do some birding or ring-reading, your re-sightings would be greatly appreciated!

Tuesday, 20 May 2014

Well Spotted!

Last night, Monday 19th May, we had one of our most interesting colour-ring re-sightings to date. Its the first Dublin Bay Birds Project colour-ringed Redshank that has been re-sighted outside of Ireland. In an extraordinary coincidence, the bird (colour-ring BH) was spotted by BirdWatch Ireland's very own Olivia Crowe whilst over in Iceland on a Knot ringing expedition, which is  co-ordinated by Jim Wilson as part of The International Wader Study Group.

The team was out late Monday evening attempting a cannon-net catch on a flock of 9,000 Knot in Iceland's westerns fjords, when BH was spotted with nine other unringed Redshanks. 

Redshank BH - ringing site (Dublin Bay) to re-sighting location 
(Iceland's western fjords). Roughly 1,700 km!

We ringed BH on the 1st February this year at Sandymount Strand in Dublin, and hadn't had any re-sightings until this report from Dyrafjorour in Iceland late last night.

Redshank BH - re-sighting location, Dyrafjorour, Iceland. Olivia Crowe. 

Remember that all re-sightings are hugely valuable us, so please keep them coming in. You can submit your records HERE.

Friday, 2 May 2014

Visible Migration

This week we had a report from a local birder of a colour-ringed Dunlin in South Dublin Bay on April 21st. As part of the Dublin Bay Birds Project, we have ringed a good few (hundreds) Dunlin but we haven’t colour ringed any. We know that the bird was ringed as part of a wader ringing project in North West Africa, at Banc d'Arguin, Mauritania, on January 9th 2013. 

Northward bound - colour ringed Dunlin, 
South Dublin Bay

The Banc d'Arguin stands on the African Atlantic coast, where the ocean and the desert meet. The area comprises shallow coastal areas with extensive mudflats covered by seagrass, small islands, coastal swamps and sand dunes. It is one of the most important areas in the world for migratory waders, holding approximately 2 million birds.

From ringing site to Dublin Bay, but where in between?

We get three difference races of Dunlin in Ireland, two of which, schinzii and artica, winter in west Africa. The schinzii race breeds in small numbers in the northern extremes of Ireland and the UK, as well as in south eastern Greenland, Iceland, the Faroes, Norway and the Baltic. Small numbers of slightly smaller and shorter-billed artica birds move through on passage en route to and from north eastern Greenland each year.    

We are always on the lookout for re-sightings of colour ringed birds, so if you see any, and can read the inscription, combination of colour rings or get a good photo, we would be delighted to have the record. Thanks to all our regular and casual ring readers, we hope you have been enjoying the good weather recently - perfect for ring reading...

Observations can be submitted here.


Wednesday, 16 April 2014

Survey "work"

While you were all slaving away in your offices yesterday, the Dublin Bay Birds team was out surveying in Dublin bay, where the sun was splitting the stones. There is no better way to count waders, than with Skylarks providing the tunes and with Swallows acrobatically chasing overhead. As I stood on the causeway in my tee shirt with my ice-cream, I wondered if I should have brought sun cream. Then I pinched myself, and started my work

There have been big changes around the bay since last month’s count. The Wigeon, Teal, Shoveler and Pintail have all gone, and the Brent Geese are fervently fuelling up for their imminent departure. The Oystercatcher numbers have more than halved since last month, and the Bar-tailed Godwits have all but disappeared. There are still plenty of Black-tailed Godwits around, but now, sporting their tomato soup-coloured glad rags, they really stand out on the mudflats. There are also lots of Redshanks around now too, but these ones are likely to be birds that have wintered further to the south, who are on their way northwards.

Black-tailed Godwit in breeding plumage Shay Connolly

I stopped in at Merrion Gates to read some Oystercatcher rings on my way to back to the office, and was delighted to hear the grating kerrick calls of Sandwich Terns over the strand. These harsh calls foretell the arrival of their Common and Arctic cousins, who will be arriving back to their breeding platforms in Dublin port in the coming weeks.  

Sandwich Terns in breeding plumage Shay Connolly

Just two of our radio-tagged birds, Redshanks AN and AP, remain from the eleven birds we tagged in January. We got some great data from them before they left, and now the job is to get this data out of notebooks, mapped and moulded into something useful!  

Wednesday, 26 March 2014

See you in Iceland!

I got an email this morning from Jim Wilson, who coordinates the fantastic International Schools Godwit Project. Jim had been contacted about colour-ringed Oystercatcher “CU”, which had just been seen in Stokkseyri in southern Iceland! This is great news as it is the first re-sighting of our Dublin-ringed birds in Iceland!

Wintering and breeding sites for Oystercatcher CU.
Blue marker: ringing and wintering site.
Red marker: breeding location.

CU is reported to be on its breeding territory with its mate.  It had been re-sighted 5 times on Sandymount Strand since it was ringed there on the 26th February, 2013, with the most recent re-sighting being on the 4th March this year.

Oystercatcher CU on breeding territory in 
Stokkseyri, Iceland.  Tómas Grétar Gunnarsson 

While we don’t know what age CU is, we know that it hatched at least four years ago. CU had a bill length of 78 mm when we ringed it, which suggests that it tends to prise open cockle and mussel shells, rather than smashing them open like some of its shorter billed buddies.

Tuesday, 25 March 2014

Things that go bump in the night

I didn’t see a fox while out radio tracking last night. And it was the very first time that I didn’t see one on a nocturnal radio tracking survey. We are practically tripping over them at night in Dublin. We often see them picking their way along Sandymount Strand scavenging stranded treats laid down by the withdrawing tide, or, at the weekends, skulking in the shadows en route to the chipper to feast on deep-fried treats discarded by the withdrawing revellers.

But this is supposed to be a bird blog, and everyone else seems to be blogging about the signs of spring, so maybe I should too. As I’m practically nocturnal these days, you might think it would be hard to notice anything, but there are some signs:

  • There has been a constant passage of Redwings every night that we have been out in recent weeks. Their diagnostic tseep calls have been providing pleasant backing vocals to our nocturnal endeavours. After fuelling up all day, no doubt on the abundance of berries that still adorn many trees, they take advantage of the cool night air and lack of predators to make their northward migration.
  • We’re not doing such a good job at tracking the wintering birds anymore, as the radio-tagged waders seem to have the same idea as the Redwings. A few weeks ago, we’d be able to get fixes for all of the eleven radio-tagged birds each night, but this number has recently taken a nosedive. We only had three last night: D A, the one remaining Oystercatcher; A N, the Redshank pictured in the banner above; and D C, my second favourite of the Bar-tailed Godwits.
  • Also with procreation on their minds, Robins, Wrens, Blackbirds and Song Thrushes, coerced by a concoction of street lights and testosterone, have been heralding springtime by belting out their songs in the better-lit parts of our survey site.
Nocturnal radio tracking. Niall Tierney

Spring is surely on the way, and it won’t be long until all our winter visitors have left our shores. So it’s a great time to get out to Dublin Bay to read the rings on the birds that aren’t ready to leave yet, but it’s also worth keeping an eye for colour-ringed waders elsewhere, as they are on the move.  

Thursday, 6 March 2014

Remember this guy?

We blogged about him in last April. He was ringed as a juvenile on the 16th September, 2012 in the Montrose Basin in NE Scotland. Since that blog last April, he was seen again on Bull Island on the 2nd of May, 2013 before heading off to breed.

Colour-ringed Black-tailed Godwit Ewan Weston

He is back in Dublin again and has been seen and photographed several times on Bull Island, with the most recent sighting being on the 23rd February.

Colour-ringed Black-tailed Godwit Graham Prole

Isn’t it fantastic how much we can learn from these colour-ringed birds? Check out this link to read about what godwit researchers are learning about how climate change is affecting the timing of migration. 

Sunday, 2 March 2014

Tuned In

Following on from our big catch in late January we have been up and down the length and breadth of Dublin Bay radio tracking the 11 radio-tagged birds. Of the 11 birds fitted with transmitters,  4 are Oystercatchers, 4 are Bar-Tailed Godwits and 3 are Redshanks. In the month since we have been extremely busy tracking the birds' movements both by day and by night at both high and low tide states.

Helen & Niall on a tracking session at Shelly Banks

A typical radio tracking transect between West Pier (Dun Laogaoire) and Sutton takes in up to 15 vantage points (VP). At each VP we use a receiver with a Yagi aerial to scan for and pick up the individual frequencies from the birds. The Yagi aerial looks like a rooftop television aerial and attracts lots of attention and funny comments from passing traffic. Once a frequency is detected, we plot the direction of the strongest signal an effort to map the bird’s location.

On each visit, we encounter most of the frequencies across the transect VPs. We are already starting to see some patterns; for example, the Oystercatchers tend to use the same parts of the bay more consistently than both the Bar-wits and Redshanks. It’s fantastic to get such immediate results and is a really rewarding but challenging survey method. The weather, traffic noise and tech issues are among some of the challenges encountered by the team.

Soft Day Out!

When we are out on transects we are always on the lookout for colour ringed birds to help gather more data on individual movements. This helps to reinforce and compliment the data we have gathered through tracking and core count surveys. We welcome new ring readers and are delighted to receive any sightings of colour ringed birds. If you are keen to get involved or report a sighting please get in touch with Niall Tierney ntierney@birdwatchireland.ie

We have another action packed month ahead before the birds head off to breed. Make sure to say hello if you see us out and about in the coming weeks!

Thursday, 20 February 2014

More Celtic links

Remember the two Oystercatcher “controls” (birds that are previously ringed as part of another project) that we caught last February at Merrion Gates? Well, we colour-ringed them and they became F H and H D. The numbers of their metal rings were sent to the BTO to find out about their origins and we’ve just heard that they are both Scottish.

On the 19th June 2004, F H was ringed in the nest in Berneray, North Uist in the Western Isles (blue marker) and   H D was ringed, also as a nestling, on the 5th June 2010 in Wester Fodderletter, Highland (red marker).

Blue: North Uist, where FH was ringed. Red: Wester Fodderletter,
where HD was ringed. Green: Sandymount
Strand - wintering grounds for both birds.
The colour-rings have allowed us to keep a close eye on them on their wintering grounds in Dublin, and these conspicuous rings will also mean that their subsequent movements can be tracked by birders in Ireland and further afield.

F H was re-sighted by our team of ring-readers on Sandymount Strand in September, October and December last year, but has yet to be recorded this year. H D had its ring read twice before it left Dublin last spring, and was picked up again from the 18th July onwards, after returning from its breeding grounds. 

Wednesday, 12 February 2014

So I came across this on the internet…

Posted on the blog of Oystercatcher enthusiast and one of the latest recruits to our ring-reading army, Clare Scott. 

In other news, we’ve been flat out radio-tracking and ring-reading in Dublin since the catches, so apologies that I’m a wee bit slow getting back to folk with the histories of the birds they’ve read. Keep ‘em coming – I will get through the backlog.

Who knew how hard it would be to keep up with eleven radio-tagged waders? Note to self: get satellite tags next time! We’re doing OK though (despite one of the Redshanks giving us the run-around), and will be able to generate some solid science off the back of this. Only managed a handful of ring-reads today at Bull Island: a few of the Sandymount-ringed barwits from last week and two of the Bull Island-ringed Redshanks.

Tuesday, 11 February 2014

One thousand, seven hundred and twenty two

That's how many we caught!

On Monday 27th January, a crack team of Scottish cannon netters arrived into Dublin to assist the Dublin Bay Birds team catch and colour-ring some waders. The Scottish team, or Team AwesomeTM, as they (aptly?) call themselves, hit the ground running and went straight out to recce sites in north Dublin Bay. Further recces were carried out the following day, before an evening mist-netting session produced 27 birds. One of which, a Redshank, was released after colour-ringing in a technologically advanced state, with its radio transmitter beeping away as it flew off over the Tolka Estuary and onto Dollymount Strand in the darkness.

Colour-ringed Redshank.
The blue ring represents the t
he Bull Island south
 lagoon ringing site.
Niall Tierney
Wednesday morning saw the team converge on the south lagoon at Bull Island in an attempt to cannon-net some Redshank. As luck would have it, a group of foraging Redshank were flushed from the adjacent driving range by a golfer, and, in an incredible stroke of luck (or more Team AwesomeTM genius?), the birds immediately landed right in front of the net, which was promptly fired. Six Redshank caught. All were colour-ringed and two were selected to be fitted with the two remaining Redshank radio transmitters.

But these catches were merely chump change compared to Thursday’s jackpot…

With the forecast looking good, the wind direction being just right to push the roosting birds into the best catching spot and the mid-morning high tide being just the right height to further corral the birds, it seemed the stars were aligning for a great catch.

We assembled at Booterstown DART Station at 07:00 for a briefing. The large team, which comprised Team AwesomeTM, BirdWatch Ireland staff, NPWS, members of the Irish Midlands Ringing Group, local ringers, ring readers and the Dublin Bay I-WeBS counters, made light work of ferrying the gear out to the spit. As we were cut off by the encroaching waves, and as the tide forced the foraging waders towards their roost, we lay down in the marram grass and the anxious wait began.

Tension mounted as the tide reached its climax. The radio chatter from the firing position was positive - it was looking good. The final instructions were given and red button was pressed! Suddenly, everyone was moving. Legs, that were numb from hours lying on the cold sand, were forced into action to race to the nets to extract the haul. Hundreds of Knots, Bar-tailed Godwits, Dunlins and Oystercatchers had been caught! As the extractors bent to their task, the “runners” ferried the birds to the waiting holding pens where they would be kept calm before ringing. While the Knot and Dunlin were BTO ringed and released, a sample of the Bar-tailed Godwits and all of the Oystercatchers were colour-ringed. Four of each of these species were also fitted with radio-transmitters. In the catch, we had "controls" (birds ringed elsewhere) from the UK, Germany, Norway, Iceland and Holland - watch this space for more info on these birds. Ewan, one of the Scottish team, recognised the ring number on one of the Knot and later told us that he had ringed the bird as a juvenile on the Ythan Estuary in Scotland in August 2009!

In all 1,673 waders were ringed and released on the day - a mammoth effort.

Radio-tagged Oystercatcher "AD" Simon Foster
A much smaller team regrouped the following morning for more cannon-netting, this time on the dropping tide at Merrion Gates. Redshanks were once again the intended targets, and before long, a small group of "smalls" were netted. Saturday followed a similar pattern, and between the showers we managed a small catch of 6 Redshank and 2 Dunlin.

A great week’s ringing, but in a way, the work is only just beginning. There’s no point colour-ringing birds if you’re not going to re-sight them! And there’s no point deploying radio-transmitters if you’re not going to put them to good use! And that’s partly the reason for this blog going up so long after the catches! We have been out and about in Dublin Bay (and beyond) reading the rings and radio-tracking. One of the research questions we have is whether the birds use the same areas by day and at night. Without round-the-clock radio-tracking, this would be very difficult to answer comprehensively, but round-the-clock radio-tracking means that…well, it means that we get no sleep, but more importantly, it means that we can delve even further into questions surrounding how these birds are using Dublin Bay and find out a huge amount about their wintering ecology and behaviour. 

Please make a special effort to get out and about to search for these ringed birds. I always say this, but every ring read is potentially a missing jig saw piece or the start of a very interesting story. I always say this too, but the welfare of the birds is always paramount - this sustained spell of stormy weather and very high tides is already challenging the birds - so it’s vital that you don’t disturb them by getting too close while ring-reading. Please submit your sightings using this page, or by email to ntierney@birdwatchireland.ie

Totals for the week (new/control):

Knot: 915/10
Bar-tailed Godwit: 470/5
Dunlin: 265/4
Oystercatcher: 30/2
Redshank: 16
Turnstone: 3
Curlew: 1
Ringed Plover: 1

Total: 1,701/21