‘SOCIABLE DOLPHINS’: MELON-HEADED WHALES


Melon-headed whales, Bahamas (BMMRO / Field School)

‘SOCIABLE DOLPHINS’: MELON-HEADED WHALES

Last month, BMMRO undertook a joint expedition with FIELD SCHOOL to carry out research on sperm whales. This took them out into deep water, where another, quite different, cetacean species was also encountered on the final day – a huge pod of more than 100 melon-headed whales Peponocephala electra.

Melon-headed whales, Bahamas (BMMRO / Field School)

The melon-headed whale is in fact – like the FALSE KILLER WHALE I recently wrote about – a species of dolphin. It is sometimes more accurately called the melon-headed dolphin, which removes any confusion. These creatures are oceanic, preferring deeper waters. For that reason they are not often encountered, despite being quite common in tropical and sub-tropical waters around the world.

Cetacea range map Melon-headed Whale.PNG

Melon-headed whales, Bahamas (BMMRO / Field School)

The MHW belongs to a dolphin species commonly known as blackfish. Other dolphins in this group included, for the Bahamas, the pygmy killer whale and the more frequently encountered pilot whale, a species than can be seen in the Sea of Abaco.

In some of these photos you can see the distinctive white lips of the MHW Melon-headed whales, Bahamas (BMMRO / Field School)

Melon-headed whales are notably social animals. They live in large groups – often more than 100-strong (as the expedition found), up to as many as 1000 individuals. Within these large groups, smaller groups of a dozen or so form and stay close as they swim.

Note the ‘Rainbow Blow’ caught in this photoMelon-headed whales, Bahamas (BMMRO / Field School)

MHWs appear to communicate or perhaps to bond by touching flippers. MHWs also associate with other dolphin species, and they have even been recorded with large whales such as humpbacks.

Melon-headed whales, Bahamas (BMMRO / Field School)

Other observed behaviour includes sub-surface resting in numbers, boat-wave riding, and so-called ‘spy hopping’ (above). This last activity may be carried out by several resting animals,  which jump vertically out of the water and splash back again into the ocean (see also the Header image).

Melon-headed whales, Bahamas (BMMRO / Field School)

This video was recorded during the expedition. You’ll get a very good idea of the size of the group from the drone shots as they pull out. I doubt that many people would expect to see such large sea creatures in such numbers – it must be an awesome** sight.

10 MELON-HEADED FACTS WITH WHICH TO ASTOUND YOUR LOVED ONES
  • The MHW’s head is rounded, lacking the obvious beak of more familiar dolphins
  • The darker grey face is sometimes called a ‘mask’
  • Their distinctive white lips are a good identifying feature
  • They are capable of swimming at very fast speeds
  • Like other dolphins, they make series of low jumps out of the water as they swim
  • Their groups often contain 100 individuals, up to as many as 1000
  • An adult grows to around 3m / 10′ long
  • They live for at least 20 years, and females may live as long as 30 years
  • As with many certaceans, their favourite food is squid
  • Oh, did I mention that they are really dolphins and not whales at all?

CREDITS: all fantastic photos & the original of the video clip – © BMMRO /  Field School

** In its true and original meaning of ‘inspiring wonder and awe’ (historically, in a religious sense), rather than the diluted modern usage as in ‘awesome pizza’ or ‘awesome selfie’

BAHAMAS WHALES & DOLPHINS IN ABACO & ANDROS WATERS


Melon-headed Whale breaching - BMMRO copy

Melon-headed Whale breaching – BMMRO

BAHAMAS WHALES & DOLPHINS IN ABACO & ANDROS WATERS

The Bahamas Marine Mammal Research Organisation (BMMRO)  has its HQ at Sandy Point, Abaco. We recently went out in their research boat, a RHIB, to spend an unforgettable day with Blainville’s beaked whales and bottlenose dolphins. I posted some of the dolphins HERE; and a two-part beaked whale post is a work in progress.

Male Blainville’s beaked whale with its extraordinary barnacle-encrusted teeth that protrude upwards from its lower jaw. The prominent beak is plainly visible. Sighted off the south-west point of Abaco during our second encounter with a group of these whales – the only male we saw that dayBlainville's Beaked Whale KS 1

Abaco waters are ideal for marine mammals, especially off the southern shores where the walls of the Great Bahama Canyon drop vertiginously down from the shallow coastal waters to depths of up to 3 miles below. This is one of the deepest ocean canyons in the world.  The area provides a rich source of food and nutrients for the whales and dolphins and many different species are regularly sighted there, from huge sperm whales to small pilot whales (including plenty of species I had never heard of before). 

Great Bahama Canyon Map edit

As the name suggests, the BMMRO’s remit extends far beyond Abaco. The researchers often spend time exploring and recording cetaceans in other Bahamian waters. For the last few weeks the team have been off Andros and have encountered quite a few target species. I have included a selection below taken within the last month to illustrate the importance of the area for a remarkable assortment of wonderful whales and dolphins.

BLAINVILLE’S BEAKED WHALEBlainville's Beaked Whale copy

DWARF SPERM WHALESDwarf Sperm Whales - BMMRO copy

PANTROPICAL SPOTTED DOLPHINSPantropical Spotted Dolphin - BMMRO Pantropical Spotted Dolphin leap - BMMRO copy

On board the research vessel, every sighting is recorded in detail – where possible by species, numbers, ages, sexes, and individual identifying characteristics. Thus ‘SW34’ may have a damaged fluke, whereas ‘RD49’ may have a long scar on its back. 

PILOT WHALESPilot Whale - BMMROPilot Whales - BMMRO copyPilot Whales 2 - BMMRO

The research boat is equipped with sound devices which, when the microphone is immersed, are capable of picking up whale or dolphin sounds from a considerable distance. It’s astounding to be able to listen in ‘live’ to the wide assortment of clicks and whistles produced as the creatures communicate with each other. The recorded sound patterns are studied and can often be matched to enable an individual animal to be identified. 

MELON-HEADED WHALESMelon-headed Whales - BMMRO Melon-headed Whale - BMMRO

RISSO’S DOLPHINRisso's Dolphin - BMMRO copy

Other work, including photography, is done underwater. Perhaps the most intriguing aspect is the collection of poop specimens, from which a great deal can be ascertained about the diet and health of an individual animal. I wrote about this task and the methods used a while ago inFAMILIAR FECES‘.

I’ll be writing more about whales soon. Meanwhile, here’s a short BMMRO video of a large group of melon-headed males. At the start, you can clearly hear communication sounds between them.

Credits: Charlotte & Diane of the BMMRO for taking us out with them and for all the photos except the male Blainville’s beaked whale (mine, for once!)