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

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!