A SPECIES of dolphin that is often confused with killer whales is turning up in increasing numbers off the coast of Co Kerry and the southwest this summer.
The Irish Whale and Dolphin Group (IWDG) reports a 53 per cent increase in sightings of the pale-coloured and sometimes white Risso’s dolphin, – also known as Grampus griseus – compared to last year.
For the first time their vocalisations have been recorded in Irish waters and their photographs have been taken.
The shy dolphin, rare in inshore waters, has turned up in numbers just metres from the shore along Slea Head and the Blasket Islands, and most recently near Puffin Island in St Finan’s Bay.
As many as 20 have been recorded in one pod.
According to the IWDG, the Risso’s dolphin is poorly understood in most waters within their range, which includes most oceans, except those in polar regions.
“This may in part be due to their shy nature and reluctance to associate with boats,” the group said.
“But in recent weeks, we have noticed a significant increase in sightings of this species from counties Wexford, Cork and Kerry,” it said.
Using rigid inflatable boats, the group has tracked the mammals’ movements and recorded their calls over a number of days in late June.
Up to 20 were spotted on June 20th alone.
Three days earlier, a group of five Risso’s were observed milling just off the cliffs east of Fahan, Slea Head, and over the next hour and a half the animals made their way to Slea Head, and “appeared to be foraging along the rocky seabed close to the shoreline, no more than 20m out”, according to the IWDG.
Reaching up to 4m in length, Risso’s dolphins may be confused with juvenile or female killer whales due to their large dorsal fin and bulbous head shape.
However, the dolphins have no teeth in their upper jaws.
“But if seen in good light with the sun behind you, their very pale-white coloration, combined with the extensive scarring, giving them a unique ‘marbled’ effect, should make them easier to tell apart from other dolphins, such as bottlenose, which are regularly seen in Irish waters.”
The dolphin may be following squid, its favourite food, the IWDG said.
The Irish Whale and Dolphin Group is appealing for reports of sightings, which may be logged on its website, iwdg.ie