Friday, 22 March 2013

BANG!! The Dublin Bay Birds Project is well and truly underway.

On the 26th February, a team of BirdWatch Ireland ornithologists and volunteers were joined by members of the Highland and Grampian Ringing Groups to catch and colour-ring Oystercatchers at roost near Merrion Gates. We arrived on site at 06:30 to set the cannon-nets at the tip of the newly formed spit between Booterstown DART Station and Merrion Gates on Sadymount strand, Dublin. The idea is that the rising tide pushes the birds up the beach towards the cannon-net, and it gets fired over them as they roost. We expected that they’d be in position around high tide, which was at 11:47. And so the stakeout began....

While the licenced cannon-netters took up the best viewing positions, the rest of us kept well back to ensure we didn’t disturb the birds are they foraged ever closer to their roosting position on the spit. We couldn’t see what was happening at the catch site and relied on the cannon-netters to keep us informed via walkie-talkies.

While we couldn’t complain about the weather, as it was dry and bright, all those layers of clothes were needed as we sat on the cold sand. We kept ourselves warm with coffee from our flasks and tried not to tempt fate by talking about how many we’d catch. 

The catch team. SinĂ©ad Cummins

We were keeping our heads down and couldn’t see what was going on, but we knew that the encroaching waves would be eating up the remaining foraging area and pushing the birds towards their roosting position, and the catch zone and that we could be called into action at any time. Tension mounted. If the birds weren’t in the catch area when the tide reached its summit, we knew we’d have to stand down and try it all again tomorrow.

However, as high tide approached, the radio chat was positive and a wave of anticipation swept around our small group. That is, until we heard that three Oystercatchers had marched up the beach and roosted right in front of the net. This meant that the net couldn’t be fired as they birds weren’t in the safe zone. Could these three birds have inadvertently ruined weeks of meticulous planning? Would we have to call the whole thing off and wait until tomorrow? Luckily, those three didn’t fancy roosting there and wandered off after a while, meaning the possibility of a catch was back on  ...but there were still no birds within the catch area.

As high tide approached and the radio chatter became more and more pessimistic, we began thinking about getting back to the office and getting to all those other jobs that this cannon-netting has superseded.

...Then something happened - I still don’t know what, and a portion of the birds moved into the catch area. Now it was up to the cannon-netters to pick their moment to fire the net over the roosting birds. As we scrambled to put lids on our flasks and load ourselves up with the ringing equipment, we heard the words over the radio that we’d been waiting for all day: “firing in ...three, two, one!”
BANG!! Suddenly we were all scrambling to get ourselves and gear to the catch site. Moments later the holding pens had been erected and the birds were being taken from under the net. The ringing table was set up, the various tasks were allocated and we began to process the birds.

We caught 119 Oystercatchers and a Ringed Plover. Each bird was ringed with a BTO metal ring (see BTO ringing scheme here) with a unique number and address. In order to determine body condition, a series of measurements were taken (wing, tarsus and bill length and weight). Each bird was aged using plumage details and the colouration on the legs, bill and eye. Finally each Oystercatcher was fitted with a series of plastic colour-rings to give each bird a specific identity.

Colour-ringed Oystercatcher "IV"  Richard Nairn

A special thanks to all the volunteers who gave their time to get this aspect of the project off the ground. Every pair of hands was needed to ensure that the birds were caught, processed and released promptly and without any problems. But the voluntary help doesn’t end there! We’re calling on all birders to make a special effort to read the inscriptions on the rings before the birds leave our shores to head off to breed.

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