IWDG match another Irish Humpback whale

24th Oct 2008 One of the two humpback whales photographed off Mine Head area, Co. Waterford last Friday 17th Oct. can now be confirmed as yet another humpback match within Irish waters.....

There aren't too many advantages to long periods of poor weather, especially when they are in the middle of our large whale season. But one of them is that it gives us more "desk time" during which we can analyse the hundreds of images secured during fieldwork. Yesterday was one such day.

On 11th Oct 2004 John Leech secured images of a single humpback whale northwest of Loop Head, Co. Clare, from the Irish Naval Service vessel, L.E. Eithne. Although they were distant, slightly blurred, and taken in poor light, some images were good enough to merit assigning this animal a unique number (HBIRL6) and we added it to the Irish Humpback whale catalogue, which proved to be a good move.

Yesterday, our colleague Dave Wall emailed us from the RV Celtic Explorer which was sheltering in Smerwick harbour, Kerry from the storm force conditions that lashed the coast. He felt that John's humpback from Clare was a close match with one of the two humpbacks we photographed last Friday 17th Oct off Waterford.


So as always, this process begins with a fresh pot of coffee, and then the matching began. After an hour or so looking at key features such as dorsal fin and hump, tail flukes and unique marks such as the "scalloping" along the edge of the flukes, we had the collective "nod". This was another humpback match.

HBIRL6 white scar on dorsal surface left fluke © John Leech & Pádraig Whooley, IWDG

This is another important large whale story, as this match shows this adult humpback whale in two very different sites in the same month, seperated by 245 miles and 4 years. It also demonstrates strongly the contrasting status of humpback and fin whale populations in Irish waters and indeed the Northeast Atlantic.

The fact that every humpback whale on the Irish catalogue has been captured >1 suggests very low numbers of this species in Irish waters. One for instance, HBIRL3 has been sighted 27 times over 7 years, and most have been re-captured between 2-3 years. As all known Irish humpbacks have been re-sighted in Irish waters (one in the North Sea) this suggests strongly that the Irish humpback catalogue contains most of the humpbacks that regularily visit our waters.

This is in stark contrast with fin whales, where the opposite is true. Most fin whales we capture (photograph) are animals previously not photographed, and thus the Irish Fin whale catalogue continues to grow with each photo-ID trip. For instance on last Friday's trip to Waterford with Colin Barnes, we observed c7+ fin whales, of which 5 were well photographed, and of these one was a known animal, and the remaining 4 were new, and were added to the catalogue, which currently comprises 48 recognisable fin whales.

This is an important resources and as with all other IWDG data, the Irish humpback and fin whale catalogues are available online to everybody. See the following drop down menu to select the species catalogue you want to see.

http://www.iwdg.ie/iscope/sightings/photoID.asp?id=89

You can contribute by trying to match any humpback or fin whales you are fortunate enough to photograph. We'd love to hear what you think, especially if you feel you have made a match.

As we leave October, we enter the month which our sighting rates since 1999 have consistently shown to be the peak month for large baleen whales along the Irish south coast. So keep watching the weather windows and consider a trip down to the Irish South coast for land or boat based watches. November along the Cork coast in settled weather can provide