Bottlenose dolphin in process of giving birth from West Cork….a rare capture.

On April 15th we received a report of a large group of c.25 bottlenose dolphins off Barleycove beach in West Cork by Siobhan O’ Driscoll. As this report came with a suite of images, it didn’t require much by way of validation and was duly processed and entered onto  Two days later we received a message from local IWDG group member, Heather Mahmood, to say there was a similar sized group in Glandore Harbour that morning. This location is just under 60km to the east, still in West Cork.

During the day Heather flew her drone a DJI Mavic 3, at a respectful and safe altitude of 68-70 meters with a X7 digital Zoom.  With the news that the group were still in the same area yesterday Thurs. 18th April, several IWDG personnel went over to watch them from shore, as let’s face it, this species, although not rare, is still not seen all that frequently anywhere along the Irish South coast, where the smaller common dolphin dominates. I went over myself and found a smaller, relaxed group of about 10 animals, moving between the Sunk rock and Long Point, but still well inside the harbour area. IWDG member Maureen Jackson watched them up to about 17:00 in front of Eve Island….I hear you say, “ So what….will you ever get to point”?

Unborn calf’s tail fluke visible in this photo.

Ok….so last night Heather and her dolphin fanatic daughter, Ruá, who is a regular contributor of sighting reports, went through their drone footage and something caught their attention, which was consistent with their observations from the previous day and seemed worthy of a second opinion. So, they forwarded myself and William Helps a short 8 second clip, which posed a simple binary choice, as to whether this appendage on the undercarriage of the last dolphin to surface was a “baby or a willy?”.   Eloquently put, but to the point!

Having watched the clip over and over, I showed it to my family, over and over, to confirm I wasn’t imagining things, I concluded that it was indeed a female either giving birth or in the process of; as the appendage looked very similar to a tiny, floppy tail-fluke.  It is known that to maximise the chance of a successful birth, which can be a long process for all mammal species, cetacean calves are born tail first.  This is an adaptation to living in an aquatic environment, as it gives the new born the maximum breathing time inside the birth canal….that first breath being the critical one.

So, I sent the video clip immediately to Simon Berrow and Mags Daly IWDG/Shannon Dolphin Project, who between them know more about Tursiops truncatus than most anyone else in Ireland. Simon pondered whether it could be a still birth, but neither of them have ever witnessed the birth of a bottlenose dolphin, despite being involved in monitoring the resident Shannon population now for over 30 years.  In fairness, how could they have, as this behaviour could really only be detected from an aerial perspective, which we now have at our disposal. Drones when put to good use, can be a powerful research tool in our arsenal.

Finally, we shared this video with Dr. Barbara J. Chaney  from the Lighthouse Field station at the University of Aberdeen, who studies the Scottish bottlenose population, which overlaps with our own, and her thoughts mirrored ours, that this footage was unique, both in a British and Irish context, as this event has never before been seen, let alone recorded.  So IWDG extend a huge míle buíochas to Heather and Ruá Mahmood for taking the time to share this footage with us, which offers us important insights into this aspect of bottlenose dolphin life, and goes no small way towards improving our understanding of this large and native dolphin species an Deilf Bholgshrónach.  A first and hopefully the first of many such observations. (see last adult to surface from the right on short video clip below)

If you are on the water this weekend and you encounter this group of bottlenose dolphins, please respect the fact that this is a nursery group with several young calves, including a newborn.  Do the right thing and just leave them be.  As a coastal species, they are generally quite easy to watch from the shore, where you’ll have no impact on them.  Enjoy.

By Pádraig Whooley, IWDG Sightings Officer

Images and video © Heather & Ruá Mahmood