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 26^th February, 2013, with the most recent re-sighting being on the 4^th 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.

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.  

Remember this guy?

We blogged about him in last April. He was ringed as a juvenile on the 16^th September, 2012 in the Montrose Basin in NE Scotland. Since that blog last April, he was seen again on Bull Island on the 2^nd 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 23^rd 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. 

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!

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 19^th 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 5^th 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 18^th July onwards, after returning from its breeding grounds. 

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.

One thousand, seven hundred and twenty two

That's how many we caught!

On Monday 27^th 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 Awesome^TM, 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 the 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 Awesome^TM 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 Awesome^TM, 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