Globicephala - Pilot Whales

Pilot whale pod.

There are  two species of pilot whales: G. melas - the long-finned pilot whale, and G. macrorhynchus - the short-finned pilot whale. If you've read the entry on killer whales (above), you will recognise that these animals are dolphins, with their conical teeth and severe dorsal fins. Like the killer whales they have close familial ties and both males and females remain with their mothers long-term. Unusually, the females go through menopause - very rare among mammals, and the post-menopausal females continue to contribute to the pod and help to raise calves, so they are baby-sitter whales!

Pilot whale harvesting
in the Faroe Islands 1852

The genus name Globicephala means globe-head, and the species names are melas (black) and macrorhynchus (big beak), which are accurate, if slightly dull descriptions. The common name 'pilot whale' was given because it was believed the pod was always led by an individual - the pilot.

Black pilot whale meat with blubber,
dried fish and potato - Faroe Islands

Other names have included 'pothead whale' (because of the shape of their head, not because they like to smoke...) and 'blackfish', as the flesh of pilot whales is unusually high in myoglobin and therefore distinctly black in colour. In the Shetlands dialect of Scots they are called 'caain' (thanks to Dr Beth Mouat at the NAFC Marine Centre for this), which means 'herd'. This comes from the fact that people would drive whole pods of them, just as you might a herd of cows, into inlets where they could be 'harvested', as is still done in the nearby Faroe Islands. This is a practice which has continued for over 1000 years in the islands. It constitutes an important part of the local culture and heritage, but of course it has become controversial and is being phased out there.

Short and long-finned pilot whales

You would find it difficult to distinguish the two species if you saw them. Long-fins are a little smaller than the short fins. Male long-fins reach around 6.5 metres, whereas the short-fins get up to 7.2 metres. Males are larger than females though less long lived. Males of both species live around 45 years and females up to 60. If you spot pilot whales in the far north or south, i.e. in the Arctic or Antarctic, it's probably a long-fin, and if you spot them anywhere around the equator, it'll be a short-fin, but both species frequent temperate regions and pilot whales can be seen all over the world. With a global population of more than a million individuals, they are happily not considered to be in any way endangered.

Mass stranding

Stranded at Zandvoord, Netherlands
(artist unknown)

Pilot whales are also well known for stranding en masse, and though no one is quite sure why they do this, there are a few good theories. One possibility is that, following their leader or 'pilot' as they do, and being so tightly socially bonded as they are, if the leader strands, the others will simply follow. An individual might strand because it is diseased or, it has been suggested, they may use the Earth's magnetic fields to navigate and get thrown off by geomagnetic anomalies. There have been instances where scientists and conservationists have averted mass strandings by tricking the pod with secondary social responses (where the primary response was to follow the leader) and by taking young calves out to sea, whose distress calls then draw the older whales towards them and away from the beach.

Diving off the Azores

Forever blowing bubbles

They can dive down to 800 metres, though 30-60m is more usual, and only stay down for about 10 minutes, mostly hunting squid, though they will eat fish as well. Most whales diving deeply will remain quite slow to conserve oxygen, but short-fins, and possibly long-fins as well, will sprint even at depth, in order to catch fast prey. This is made possible partly by the fact that they have a very fast metabolism compared to other cetaceans. 

If you want to hear the voice of the pilot whale click here. The image used at the top of this blog entry is a photo of a whale named Sully. Sully was found in Curacao in the Caribbean, weak and dehydrated. With a great deal of effort, the good people at the Curacao Sea Aquarium managed to nurse him back to health and eventually it was discovered that Sully was almost completely deaf. As whales use sound to locate their food, among other things, it meant he was essentially blind and couldn't find food. He was eventually taken to Sea World (in a plane!) and given a permanent home. You can watch his story here.

Pilot whale breaching

My Pilot, Whale. 2014