22 Jan 2023

31 Oct 22 - Indonesia - Banda Sea Cruise Day 5 - Cetaceans On The Crossing From The Tanimbar Islands To The Babar Islands

This is the third Blog Post detailing the Cetaceans we saw on the crossing from the Tanimbar Islands to Babar Island. The previous two Blog Posts covered the Seabirds & an Olive Ridley Turtle. A final Blog Post will cover the Flying Fish.

Regular readers of the Blog will know that I'm a big fan of Cetaceans and I was looking forward to the Banda Sea Cruise as I was expecting to see a variety of species at regular intervals: I was not disappointed.

I will start with Risso's Dolphins which are relatively easy to identify with their pale grey and generally scarred colouration and high, narrow and strongly falcated dorsal fin. They have a very wide range in all the oceans, except for the cold Arctic and Antarctic oceans.
Risso's Dolphin: The pale grey colouration & scarring on the body allow this Dolphin to be identified as a Risso's Dolphin. It was seen at 10:52 local time
Risso's Dolphin: Another photo of the previous individual showing the classic Risso's Dolphin's thin & high-curved dorsal fin
Risso's Dolphin: This is a different individual that we saw earlier in the morning at 09:46 local time. This was a Risso's Dolphin based upon the pale grey body & the scarring
I was pleased to see my first Indo-Pacific Bottlenose Dolphins since the ones I saw at Monkey Mia on the West coast of Australia back in Sep 1991. They proved to be the commonest Dolphin that I saw on the Banda Sea Cruise. They look superficially similar to the widespread Bottlenose Dolphins, that I'm used to seeing in UK & Europe waters. Indo-Pacific Bottlenose Dolphins have a relatively robust body, moderate length beak and a tall falcate dorsal fin. However, they are more slender than Bottlenose Dolphins with a longer & thinner beak and a taller, broader-based & less falcate dorsal fin. They can grow to 2.7 m in length. Bottlenose Dolphins are very variable in the different populations around the world from 1.9 m to 3.8 m in length: with the largest populations occurring around the Eastern US & the UK coasts. As a result, the Indo-Pacific Bottlenose Dolphins always looked small too me, as I was mentally comparing them with the Bottlenose Dolphins that I regularly see around the UK coasts. They have a medium to dark grey cape on the upper body which extends along the length of the body, with a broad pale grey band below the cape & a paler belly (compared to a Bottlenose Dolphin) which has black spotting on it.

Indo-Pacific Bottlenose Dolphins are a coastal species which occur from Cape Town along the East African & Madagascan coasts, the coasts of the Arabian Peninsula, the Indian Subcontinent, South East Asia, the Philippines, Indonesia, New Guinea, the Solomon Islands, Australia, Vanuatu & New Caledonia.
Indo-Pacific Bottlenose Dolphin: A close up showing the long slender beak, which would be longer on a Spinner Dolphin
Indo-Pacific Bottlenose Dolphin: A close up showing the broad-based and only slightly falcated dorsal fin. All the other Dolphin species that are potentially in range have more falcated dorsal fins. This also shows the extent of the dark cape in front of the dorsal fin
Indo-Pacific Bottlenose Dolphin: Four of a party of five Indo-Pacific Bottlenose Dolphins that we saw at 07:30 local time
Indo-Pacific Bottlenose Dolphin: This shows the extent of the dark cape behind the dorsal fin
At 11:16 local time we encountered a logging Cetacean. I've a number of photos of it looking exactly the same as the second photo, followed by the last two photos where it turned before diving. I'm having trouble confirming the identification of this Cetacean, but the best fit is a Dwarf Sperm Whale. Any thoughts and reasons to support this identification or reasons why it is another Cetacean would be appreciated. Please leave a comment on the Blog with an email address so we can discuss it offline.
Probably Dwarf Sperm Whale: The initial view
Probably Dwarf Sperm Whale: To me this looks like the classic profile for a Dwarf Sperm Whale
Probably Dwarf Sperm Whale: Another photo of it logging
Probably Dwarf Sperm Whale: It came up for another view as we started to pass it
Probably Dwarf Sperm Whale: A final view of the dorsal fin & it was gone