Guest Blog: The Dalkey Terns

And now for something completely different... Today we have a blog post from Andrew Butler, the Dalkey Island warden, where we're hoping to establish a colony of Roseate Terns after years of intermittent breeding attempts:

To the north of Dalkey Island lie two small islands, one with some vegetation and one just bare rock. These are Lamb Island and Maidens’ Rock and are home to three species of tern; Common, Arctic and Roseate.

This season for the first time since the late 1990’s we have 32 roseate tern nest boxes on Lamb and 7 on Maidens’, it is also the first time there has been an employed Warden for the islands since the late 1990’s. The new warden and nest boxes are in place thanks to the support of the Roseate Tern EU LIFE Programme, Dun Laoghaire & Rathdown County Council and of course BirdWatch Ireland who run the project.

As well as the nest boxes we have also placed some gravel in the depressions in the rock as nesting substrate, to make the site as attractive as possible to terns looking to breed, especially Roseate Terns.

Loading 'Ken', the ferryman's boat, with nestboxes and gravel amongst other supplies.

We made our first visit Monday 16^th May to assess the site and put out some of the gravel then brought out ‘tern meadows’ estate on Tuesday. To our delight we recorded our first egg on the gravel we had placed the day before, an Arctic laid evening 16^th or 17^th on Maiden’s Rock.

The first egg (Arctic Tern, foreground),  Roseate Tern nest boxes and Steve Newton spreading gravel. for nesting Terns A. Butler, taken under NPWS license.

On 23^rd May I made my first dedicated nest search. On Maidens’ Rock I found 5 Nests and 8 Eggs, however one was predated so 4 NESTS and 7 EGGS were recorded (mostly Common).

Since then, I have covered the site weekly to survey the nest status.

Between 4^th & 7^th June I counted 105 nests between the 3 islands with one nest on Dalkey Island. I hope it’s not doomed as it is surrounded by large gulls, at least they keep the crows away. The nests had a total of 209 eggs.

2 of our first Arctic Tern chicks, one hidden in its neighbour’s nest. A. Butler, taken under NPWS license.

During latest survey between 15^th & 18^th June I found that 17 nests had been predated, however there were 10 new nests. There was a very significant milestone; we have our first chicks! 23 chicks between the 3 islands, so the lone nest on Dalkey has a chick. We have 169 eggs at the latest count.

Most of the terns currently nesting are Arctics. I hope to have a more accurate split between species as the chicks hatch. This could be a record year in terms of total terns but with no Rosies it’s not the best it could be.

We did have a Roseate visit Thursday 2^nd but I didn’t hang around.

View of Tern Meadows, Tuesday evening. Taken under NPWS license.

It’s not all about the birds in Dalkey though. Being beside a big centre of population, people are important in the context of the project and its success. With that in mind and because it’s always nice to introduce people to the wonders of birds I have been running events at Colliemore Harbour and on Dalkey Island. 

Every Tuesday evening and a few we have the Dalkey Tern Watch from the pier, spotting all the birds we can, with most oos and aahs coming from gull and Oystercatcher chicks so far. The walks on the island run after the weekend tern watch, where I tell people about the species breeding on the islands and the importance of giving them space. So far the events have been very successful, so thank you to both those who have just happened upon the events and those dedicated visitors. I’m glad to see a few familiar faces return each week.

Tuesday evening Tern Watch at Colliemore Harbour.

Great Black-backed Gull adult and three chicks seen on the Nature Walk event on Dalkey Island. Picture by A. Butler, taken under NPWS license.