Distinctive colour patterns help to track whales
Pádraig Whooley, Sightings Officer with the Irish Whale and Dolphin Group (IWDG), recently reported an interesting sighting of a Humpback Whale. The sighting happened to be in Africa and what was interesting about it was that the animal involved had previously been seen feeding in Irish waters.
Humpback Whales get their name from the fact that when they submerge after surfacing to breathe, they flex their spines and hump their backs and dive at such a steep angle that they expose the undersides of their tails as they go down.
Like a fingerprint, each animal has a distinctive colour pattern of natural markings on the underside of its tail flukes. Whale biologists photograph these patterns and contribute their images to photo-id catalogues. Whales can therefore be identified individually if their details are recorded in the photo catalogues.
On 10 March 2020, whale watchers recording blubber activity in the waters off Sal Rei Bay in Boa Vista, one of the Cape Verde islands off the coast of Senegal in West Africa, captured an image of tail flukes that matched HBIRL78 in the photo-id catalogue. HBIRL78 is short for Humpback (HB) number 78 in the Irish (IRL) catalogue.
HBIRL78 was first photographed on 4 January 2017 by Andrew Malcolm while on a whalewatching trip on MV Rebecca C skippered by the late Martin Colfer from Duncannon. Later that year, further images of both HBIRL78 and HBIRL3 were captured on 2 November 2017 by Rónán McLaughlin, then Command Officer of the Irish Naval Service vessel LÉ Orla, east of the Old Head of Kinsale, Co Cork.
The African re-sighting was the second time that an ‘Irish’ Humpback Whale was recorded in the Cape Verdes. The first was when Simon Berrow, Chief Science Officer and Acting CEO of the IWDG, captured an image of HBIRL55 on 23 April 2019 off Santa Mónica, also on Boa Vista island.
Up to recently, it was not known where the Humpback Whales that feed in Irish waters bred. North Atlantic Humpbacks are known to congregate off the Azores, the Cape Verdes and the Caribbean. It now appears that at least some of ‘ our’ animals go to the warm, shallow waters off the Cape Verde islands for females to give birth to their calves and for males, the Pavarottis of the whale world, to sing their mysterious, plaintive and complex courtship and mating songs.
For more, see the Irish Whale and Dolphin Group (IWDG) website at www.iwdg.ie.