The Dublin Bay Birds Project - a quickfire digest of recent events (dive-bombing terns to evening gull watches)

We are continuing our quest to fill many of the gaps in knowledge about how birds use Dublin Bay. Being immersed in fieldwork and data the last while means we have not been blogging as often as we like to. It is now time to take stock, and look at what has been going on.  

The 2018 summer was equal parts challenging and exciting with a big focus on the breeding tern colonies in Dublin Port, while also doing the monthly low and rising tide counts of the whole bay.

But first let's take a moment to mention the DBBP video we made with Dublin Port Company and our friends in Media Coop. We had a lot of fun making it and the bird footage is STUNNING. In case you haven't already seen it, there is a little taster below as the full video can't upload here.  Full video available at this LINK.

Back to the terns. Oh the terns. No matter how many times we make the trips out to the Dublin Port tern colonies by boat, it never, ever gets old. The contrast of nature at its most dynamic and vital – 1000+ terns industriously incubating eggs and protecting nests and screeching in the air around the colonies - juxtaposed with the similarly industrious shipping vessels and port traffic going about their business all around them is an extraordinary sight. And we feel privileged to have the opportunity to be among the birds like this, up close and personal (sometimes very personal with direct hits to our heads from defensive adult terns). Plus, seeing the city from a boat in the Liffey Channel on a sunny day is pretty special.

Tara from the DBBP Team assisting with Common Tern data collection on the Great South Wall pontoon in July 2018. Helen Boland

In 2018, there were at least 596 pairs of terns, mainly Common but a few Arctic too, that nested on the four structures in the port area. The SPA-designated structure underwent significant upgrade works, carried out by ESB, and the terns seem to have adjusted to their excellent, new, specially designed platform. And the pontoon that was re-located pre-summer to a location close to the Great South Wall provided great views for walkers along the wall with a high volume of tern activity easily visible. You can read more about the summer tern monitoring in previous blog posts here and here. 

Post-breeding tern flocks at Sandymount

Once August arrived we began looking out for the huge annual congregations of post-breeding terns along Sandymount Strand. This is quite the event with thousands of terns gathering in the bay each night just before their southerly migration. As we’ve said here before, Dublin Bay has shown itself to be massively important over those few short weeks in August and September. The highest count we had this year was 6,700 ‘Commic’ Terns - Common and Arctic combined - in September (not quite the heady heights of 17,440 from September 2016 but impressive all the same!). And we had the pleasure of being joined by the South Dublin Branch of BirdWatch Ireland that evening to soak up the sheer spectacle of it. More about these awesome (in the proper sense of the word) tern gatherings here. 

The DBBP Team with the South Dublin Branch of BirdWatch Ireland looking at thousands of Terns in September on Sandymount Strand. Helen Boland.

In addition to the 135 tern chicks we colour-ringed at their nest sites we also managed to fit colour-rings to three fully-grown Common Terns that we caught in mist-nets in the dark after one of the flock counts in September. Hopefully these birds will be seen somewhere along their flyway helping us understand more about where they go. One of the Common Terns, ‘PFF’, that we colour-ringed in Autumn 2015 at Sandymount, has been seen three times since then in winter in the Gambia! Some previous observations of our colour-ringed terns are described here.

A Common Tern fitted with a Dublin Bay Birds Project, uniquely inscribed, colour-ring ‘2P3’ in September 2018. Helen Boland.

But now we're back in winter mode and the next task for the DBBP Team is a dusk gull roost count next week. It is incredible how many more gulls are present in the bay in the evening having been inland or at sea all day. We wouldn’t have a clue how important the bay is for gulls if we didn’t carry out specially tailored counts like this. Last year we counted more than 34,000 gulls one evening in December, mostly Black-headed Gulls (~29,000), with Herring, Common, Great Black-backed and Lesser Black-backed taking up the rear in that order.  Let’s see what we find next week. Then we move on to our third high-tide roost survey of 2018, with a dawn Brent census coming down the line too. And all the while we have been dealing with the steady influx of wader colour-ring resightings of our Dublin Bay Oystercatchers on their breeding grounds in Scotland and Iceland. More on all of that soon in another post.

We will share our news and findings more frequently now that we are back on top of our hectic schedule again! The information we are gathering improves our understanding of birds, how they use the bay, and what areas are particularly important for them, and hopefully it can help with informed decision-making about Dublin Bay.