Another blog from my latest amazing trip to Antarctica, focussing on Humpback whales this time. You’ll be glad to know that there is less blood than in the previous post.
Having lived for a year on South Georgia, immersed in the depressing history of Antarctic whaling and the impact of humans on Baleen whales, it was amazing to sail through Antarctic waters and see first-hand how the whales are bouncing back. Sightings of baleen whales were frequent with the most common being humpbacks: these majestic 36 tonne beasts were almost ubiquitous throughout, it was an absolute pleasure.
Almost without fail, by the time breakfast was served on board National Geographic Explorer, there had been a blow, or a sighting of the distinctive hump, or flukes of these animals.
Possibly the best experience of my time on board came as the sun was setting on an already eventful day of killer whales and penguins. Stupidly thinking the excitement was over for the day, I retreated to my room in order to download a few photos, when the call of ‘feeding Humpbacks’ came out over the tannoy.
As a kid, I read about bubble net feeding whales and had seen footage of it numerous times on David Attenborough documentaries. For those others who have seen this footage, you will understand why seeing this activity has been on my bucket list for years. However, travelling to Antarctica, I had no expectations of ticking this off the list, since it was my understanding that such behaviour had only been observed in Alaska!
Bubble net feeding is obviously a foraging method where the humpbacks blow clouds of bubbles around their prey at the surface. This traps the prey between the bubbles and the surface allowing the whales to swim up with their mouths open and take huge mouthfuls of prey.
The video bwlow shows one of these events happening and you can see the bubbles at the surface before the humpbacks lunge through open-mouthed
Humpback whales that spend summers in the Antarctic, exploiting the rich cold waters, migrate north to spend the winters in the tropics around Costa Rica. Here, there is an overlap with the Northern Humpbacks that spend their summers in Alaska and migrate south also to Central American tropics. The hypothesis is that these Northern whales, having learnt and practiced the behaviour in Alaska, migrated south to Central America before continuing through to Antarctica.
As a result, you now have whales practicing bubble net feeding in Antarctic waters. The humpbacks have uniquely marked flukes which allow them to be identified.
Hopefully, the individuals we photographed in Antarctica will have been observed previously in the world and we will get a better understanding of how this behaviour has spread.
And when you get bored of the whales (as if!) the sunset and the ice aren’t too bad substitutes!