Bottlenose dolphins still showing well off East coast

29th Sep 2011 Coming from the East coast, I'm well used to the challenges inherent in whale watching from the few decent vantage points around Dublin Bay and'd name them on one hand. The biggest challenge was always boredom, and the risk of falling asleep and rolling off a cliff. Even on a really good day you were unlikely to record anything except a grey seal and few harbour porpoises.

Then in 2003 things started to change, as Risso's dolphins began appearing off the Wicklow coast during early summer months. This was no flash in the pan as between 2003-2007 IWDG recorded this large, pale, bulbous headed dolphin regularly during the May-July period in groups sizes ranging from 1-15 animals. Then they simply vanished almost as quickly as they appeared. From 2008-2011 we received a max of just 1 Risso's sighting during the season in this area, without a single record in 2010.

But all wasn't lost, as no sooner than the Risso's had left, than there began a steady increase in sightings of bottlenose dolphins in the very same area between 2008-2010 and most of these sightings during the same months we'd previously enjoyed the Risso's.

Now this was an exciting prospect, as we all know that pound for pound bottlenose dolphins (BND) just tick all the boxes: large, boisterous, interactive, gregarious, whilst also being indescriminate killers of porpoises and other dolphin species, with well-documented cases of infanticide not to mention a case load in Ireland of attacks on swimmers leading to serious injury and at least one overseas case of BND killing a swimmer. It's nice to be able to boast of an apex predator lurking so close to the capital.

In August 2010 however we began validating an unusual number of BND sightings on the East coast, and they shared a few characteristics; they were all in the Dublin/Wicklow area, and they were almost all of 3 animals. Photo ID images soon confirmed that these were the same group which seemed to comprise 2 adults and 1 sub-adult....and the rest as they say is history.

Since then, in the past year we have validated close to 200 sightings of this group who with the exception of 3 forays across Dublin Bay to Howth Head, rarely travel north beyond Dalkey Island, or south of Wicklow town, indicating a core range of 21 miles. An analysis of sightings shows a peak in reporting during summer months, which presumably reflects watch effort, but they are present in all months. A further analysis of their movements by simply mapping sightings on, shows that within their range, there are 3 very obvious sighting clusters, these are: Killiney Bay, Bray Harbour, Greystones Hbr-Kilcoole.

Remarkably, they seem to split their time evenly between their Dublin and Wicklow hotspots, thus making them extremely easy to locate, observe and photograph. In fact, as suggested on Philip Bromwell's report for RTE earlier this summer, the best way to find them other than checking this site, is probably to jump on a DART train in Dunlaoghaire bound for Greystones (or visa versa), making sure to look out the correct window.

Despite 1 of these 3 animals having a very well marked dorsal fin, they have not so far been matched outside of the Irish Sea, but on the 19th October BNDIRL 180 was photo ID matched in Kilkeel, Co. Down, and it is very likely that they have been photographed in other areas as well and no doubt we'll be able to bring this information to you in time.

At time of writing, this group remain perhaps the easiest to view and photograph cetaceans in Irish waters (apart from Fungie is Dingle), as we know where they are most of the time. All the images in this report have been taken

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