‘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.

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.

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 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 photo Melon-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.

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).

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’