28/05/2014 Three bottlenose dolphins stranded alive in Bahía San Antonio, a coastal region in Argentine Patagonia. The three dolphins were most likely surprised by the fast ebbing tide and ended up beached on one of the many sandbanks in the area in the early afternoon.
Thanks to the cuts and scars on the animal’s dorsal fins, the three dolphins could be recognised as Ale (RN-BSA-55/08 ), Grace (RN-BSA-56/08) and Agus (RN-BSA-57/08), two adult males and an adult female. These individuals were photo-identified as part of a long term study by one of Whalefish’s team members, and were classified as long term residents in the area.
There is a particularity about these individuals though….
Ale, Grace and Agus are morphologically different from all the other bottlenose dolphins in the area. The group is known as “the falcates”, due to their sickle-shaped dorsal fin. They are darker and larger than the rest of the bottlenose dolphins and their beak is notably shorter. Recent studies have shown their differences are not only physical, but also genetic, as they are more closely related to the offshore form of the species.
The observed physical characteristics are also seen in the bottlenose dolphins of Peninsula Valdes, and area approx. 250km south of Bahía San Antonio. It would not be surprising if “the falcates” formed part of that original population, which unfortunately today is reported as nearly vanished. Why they have migrated north to Bahia San Antonio remains a question to be answered.
They are always seen together, something very unusual among the other dolphins in the Bay of San Antonio. Their social bond is very strong, which would explain why they beached together.
Thanks to the collaborative effort of local inhabitants, coastguard, students and scientists, Ale, Agus and Grace were saved! Around midnight, when the tide was high enough, they were able to swim away safely.
The Whalefish team wishes to thank all the people that helped to ensure the survival of these three magnificent dolphins!
By Els Vermeulen
Image Source: Cota Cero Buceo
For more information :
Whalefish Research Page
Local dolphin facebook group for Argentina