(Physeter macrocephalus) The sperm whale is the largest of the toothed whales (odontoceti), males reaching dimensions over 60 tonnes and 19m (65ft). When feeding on its favourite delicacy, the giant squid, it can dive to 3000m (10,000ft.) and remain submerged for over an hour.
The whales were at the top of a food chain that balanced and regulated itself. Yet in the space of less than three hundred years, the incessant greed of man had decimated their numbers in some cases, to the point of extinction.
A wide variety of behaviours that might be seen include breaching, lobtailing, spy hopping and socialising. Breaching is when a whale launches its whole body out of the water, re-entering with a huge splash.
Lobtailing is when a whale slaps its flukes on the surface of the water. Spy hopping is when a whale pokes its "nose" above the surface of the water to have a look around.
Socialising involves a large number of whales gathering together to reaffirm their social bonds, by rubbing their bodies and vocalising. The whales spend much of their surface time recovering from their last dive and preparing for the next one, swimming along slowly, and blowing every 12-15 seconds.
Sperm whales can be found in the cold waters throughout the summer and are intensely social animals, with the females and young living in large, stable family groups. Its unusual shaped head contains 15 tons of oil, it uses these oils for decompression when its coming up to the surface from great depths. Sperm whales are identified by the shape and marking of their tails or flukes. It's their version of a fingerprint and every one has a different pattern of scallops and nicks. Unlike humpback whales, only small proportions of sperm whales have white markings on their flukes.
The first time you see a Sperm Whale fluke up and then dive, is a memory you will cherish forever. Before it dives you may have been observing the animal for 10 or 15 minutes, while it was recovering from its last dive, or perhaps it has been socialising on the surface for an hour or two, with a large group of whales. Suddenly it rears its head slightly, then arches its back a little, and goes under. You wonder whether the whale has dived, but then it surfaces again, 10 metres ahead of where it disappeared. The powerful animal thrusts its head out of the water and immediately plunges it downward towards the depths. At the same moment, the Whale's body arches strongly and you see the base of the tail rise out of the water and follow the head downwards. This is the moment you have been waiting for; the broad fluke of the mighty whale lifting skywards and flipping over, to reveal the impressive "V" of the tail. Finally the tips of the fluke still dripping with water, slide gently into the brine, and you know Moby Dick is descending to another battle with his prey, the giant squid. For hundreds of thousands of years the dolphins and great whales roamed the oceans, living in harmony with their environment.
Interested in finding out more about whales and dolphins on the west coast of Scotland?
See the website of the Hebridean Whale and Dolphin Trust