#22 and Rising

21st Mar 2013

There seems to be a lot of stranding related stories on the home page of www.iwdg.ie and some are of very interesting species such as the sperm whale in Kerry and the white-beaked dolphin in Donegal…guess it’s that time of year which is typically our “low season” for sightings.

But on the afternoon of Monday 18th March a sighting of a juvenile humpback whale off the Stags, West Cork by Micheal Cottrell bucked the trend.  Thankfully local IWDG members Simon Duggan, Youen Yacob and Robbie Murphy were on hand to venture out and locate the animal and secure photo ID images of it.  Once these images were sent to IWDG we could quickly run them through the Irish humpback whale catalogue (www.iwdg.ie)  and can confirm that this is a new humpback whale for Irish waters, bringing the catalogue to 22 recognisable individuals.

This is a great start to 2013 as the catalogue continues to grow and in recent years we’ve typically added 2-3 individuals each year to this database. So although our humpback numbers are still low, they are growing. Statistically, there is a 70-80% likelihood that this individual will be re-sighted over the coming years, as we have a very high re-sighting rate for Irish humpbacks, suggesting low numbers compared to the smaller minke or the larger fin whale.

HBIRL22 showing flukes West Cork 18/03/13 © Youen JacobIt is both unclear and intriguing as to why this animal should now appear in the same area, four months after six humpbacks (#HBIRL1, 3, 4, 6, 10, 21) were recorded in Nov-Dec 2012 during a sustained feeding episode.  Many of this group were “old timers”, as some were among the first animals added to the catalogue as far back as 1999, and by now are clearly adults.  Once these left West Cork they did not show up at any other site east along the coast as we’d have expected based on previous years sightings. So it seems reasonable to assume that being adults, the urge to migrate may  have taken them on a southbound passage towards tropical breeding grounds, the location of which remains something of a mystery for Irish humpback whales.

But back to this solitary juvenile, for which Micheal earned naming rights, and opted to name (s)he “Baltimore”.  Again, this is conjecture, but being a likely sub-adult, it is possible that the instinct to migrate south to the Carribean or Cape Verde breeding grounds is unlikely to be strong.  Young or immature male humpbacks can get injured or even killed by adult males competing for females on the breeding grounds, and so it is always possible that this individual has opted to over-winter at higher and perhaps safer latitudes. There is nothing very unusual about this, as significant numbers of humpbacks have remained this winter in the Norwegian fjords where they  have been documented feeding on herring, on occasion in association with both killer and fin whales.

Cruise track line in search of HBIRL22, 20/03/13 © Robert NewtonIWDG organised a member’s charter yesterday 20th March with Colin Barnes with a view to securing further Photo ID images and perhaps skin samples from this animal.  It was a glorious day with flat calm seas and blue skies, alas the humpback was not found, and the lack of any sightings from land watches on the 19th March would suggest that “Baltimore” has left the area.  The near absence of seabirds or other cetaceans (apart from a few porpoises) suggest there isn’t much in the way of “high value” prey available in the area to hold even a small humpback whale.  Any remaining herring are likely to be “spent” after the spawning season, so it has probably pushed on along the south coast in search of more calory rich prey.

But it’s not so much a question of “so long, farewell”; more like, "till we meet again"; as meet again, we almost certainly will. And that’s all part of the wonder of this most charismatic visitor to our shores. 

I should point out that while we were bobbing about very quiet waters in West Cork, our man in West Kerry, Nick Massett was out on his RIB in an area of Dingle Bay known as the Wild Bank, where among porpoises and common dolphins he also saw 3-4 minke whales.  There is a sense that the 2013 whale season may be showing signs of kick starting already; all of which bodes well for our summer series of Cape Clear whale watching weekends.  Bring on the sunshine, and let the phyto plankton do the rest!

HBIRL22, showing well marked dorsal fin, The Kedges, 18/03/13 © Robbie Murphy

All the latest cetacean sightings are validated and made available for online interrogation on www.iwdg.ie. It’s a fantastic resource, and we hope you have an opportunity to both contribute to it as well as make use of it in the year ahead.

Huge thanks to all recorders who support cetacean conservation in Irish waters by reporting sightings and strandings to IWDG.  The Irish Cetacean Sighting Scheme currently receives no funding or support from the government of the Republic of Ireland, so any core-funding support from corporates would be greatly apprecaited, so that we can continue to monitor and protect whales and dolphins in Irish waters.

Pádraig Whooley, IWDG Sightings Co-ordinator