From the point of view of scientific classification, these whales belong to the family of dolphins. The Pilot Whale and the Killer Whale are more like dolphins than whales and we donīt know why they have been classified as whales, but there are some strong theories which support the classification. Two groups or families are to be found off the coast of La Gomera:
the Killer Whale, including the False Killer Whale and
the Pilot Whale with its 2 species, the Short-Finned and the Long-Finned Pilot Whale.
1. The Killer Whale, also known as the Orca (Orcinus orca)
The Orca is still often called the killer whale in many of the English-speaking countries, even though many animal protectionists are aware that this name is inappropriate and misleading. It is true that Orcas attack other whales. We ourselves have witnessed a group of Orcas separate a whale calf from a group of Sperm Whales and then kill it. They also eat dolphins, seals, sea lions, birds and turtles. But they don't kill other species.
The Orcas can easily be recognised by their distinctive dorsal fin which can be as high as 1.80 metres (males) and 60 cms high in females and calves. However colouration is the main distinguishing feature and they are distinctively marked, with a black back, white chest and sides and a white patch above and behind the eye. The Orca is unmistakeable.
Male Orcas can reach about 10 metres in length and weigh up to 8 tons. The females are a little smaller, measuring approximately 8 metres. Calves at birth weigh about 200 kilos and are about 2.4 metres long. During the first few years the patches which later become white are pink or yellowish. Orcas can be found in most of the worlds' oceans, both in the high seas as well as in coastal waters.
In some parts of the world the Orcas surf into shallow water in order to catch sea lions unawares and pull them underwater. They usually hunt in groups and their method of hunting is similar to that of the seals. The group is well coordinated and a group of Orcas will corner their prey and then crush it in the water. It is said that the Orcas have no respect for each other. Normally they live in closed groups of up to 50 individual animals and it is thought that they develop a unique dialect for communicating within the group, using different tones and sounds. Female Orcas carry their calves for 14 months and then suckle them for 1 or 2 years after they are born.
Despite having no natural enemy, nor being a trophy for whalers, it is highly likely that Orcas are hunted by small fishing boats because the fishermen believe the Orcas decimate the numbers of salmon and other species of fish. Since it was discovered that the Orca is very intelligent, can learn quickly and entertain the public, a lot of money has been made from them in aqua theme parks and delphinariums and they are still being captured alive for this purpose (67 in British Columbia, Canada, alone). Known internationally thanks to Steven Spielberg's film, "Keiko" vegetated for many years in an aqua park. Now, thanks to pressure from some animal protectionists, Keiko is gradually being accustomed to life in the wild in the ocean off the coast of Iceland.
2.The False Killer Whale (Pseudorca crassidens)
The False Killer Whale looks very much like a dolphin without a beak. It is either completely black or dark grey and doesn't have white patches like the Orca does. At birth the False Killer Whale is approximately 1.8 metres long. They live in large schools in the high seas which may comprise 100 animals.
We have only seen them once off the coast of La Gomera but were still able to identify and classify them.
Pilot Whales (Globicephalidae)
There is a colony of approximately 500 Pilot Whales off the south east coast of Tenerife and each day more than 60 boats take tourists whalewatching. There is so much coming and going and resultant noise, that the Canarian government had to intervene and passed a law in 1996 to regulate the excursions. Pilot Whales can also be seen in the coastal waters of La Gomera, especially in the south around "Magic Point", though not as frequently as in the relative vicinity of the coast of Tenerife, so there is less pressure on them.
Scientists distinguish between 2 types of Pilot Whale: the Long-finned and the Short-finned Pilot Whale. Both species can be seen in the coastal waters of La Gomera, however the Short-finned Pilot Whale is more common.
The Long-finned Pilot Whale (Globicephala melanea)
Also known simply as the Pilot Whale because groups of migrating whales (sometimes up to a 100 animals) tend to follow one whale called the pilot or leader. Mature Pilot Whales are black except for a small anchor-shaped patch on their chest and can easily be recognised by their large dorsal fin which is angled backwards. The Pilot Whale often reaches 6 metres in length and has a distinctively shaped skull which resembles the flat part of the keel of modern boats. It is uncertain as to whether this is advantageous for aquadynamics, allowing them to glide through the water more easily. Be that as it may, it has not been scientifically studied to date. Mature Pilot Whales often have large scars and no one knows if they have been caused by the propellers of boats or perhaps by sparring partners during confrontations over female whales.
According to studies carried out by Canadian biologists, the ratio of males to females in a school of Pilot Whales is 2:1, but only a small number of the strongest males are the ones who control the harem. Other researchers however, believe that the social structure of Pilot Whales is basically matriarchal, i.e. that the females - or one of them - is the leader of the school and that the males are not capable of making decisions. Their only function is to protect the females and calves. This may or may not be true. Let's wait for the results of the studies which will be carried out over the next few years, especially since studies of Pilot Whales only began relatively recently.
The Short-finned Pilot Whale (Globicephala macrorhyncus)
It is almost impossible to distinguish between Short-finned Pilot Whales and Long-finned Pilot Whales at sea. The fins of the adult Short-finned Pilot Whale are roughly a fifth of the total length of the whale and so it is theoretically possible to determine whether a Pilot Whale swimming close by is a Long-finned or Short-finned Pilot Whale (but who is really interested)?
It looks as if there is also a subspecies of Pilot Whale off the coast of La Gomera called Globicephala brederlauensis which has a more pronounced forehead and grey stripes on its back. We are studying this subspecies and will have to wait until more information is available before coming to any conclusions.
Sadly, Pilot Whales have been harassed for a very long time. Throughout history whole schools of them were slaughtered after being forced into shallow waters by rowing boats. Documents in Japan dating from the 10th century bear witness to these mass killings so this has been going on for at least 1,000 years. Whales were also slaughtered off the coast of the Shetland Islands in the same way. And in the Faroe Islands there are reports of similar mass killings going back to 1584, when between 300 and 1,700 whales were killed annually. It has to be said in the defence of man that in the 16th century human beings had not yet developed a sense of ecological consciousness and also that such mass killings don't seem to have jeopardised the survival of whales in general. It appears that various factors such as the mechanisation and industrialisation of fishing, and the disproportionate fear about the benefits of such things as floating factories and the population explosion have all contributed to the near extinction of many species.
Fortunately there is now practically a world-wide ban on whaling. Only Norway and Japan continue as before, despite protests. It is more difficult to understand why the Danes in the Faroes corner whales in their hundreds in shallow waters and subject them to a painful death by harpooning and hitting them. And the whalemeat is not even for human consumption - the majority of it is used to make fodder for livestock. There is a parallel here between the above and the conditions in which your breakfast egg is produced these days.
Of all marine mammals in the waters around La Gomera, the Pilot Whale appears to be the least intimidated by man's presence.