For information on how to detect pilot whales underwater, see www.cpodclickdetector.com.
Pilot whales are odontocetes – meaning toothed whales -from Greek: ‘odont’ for tooth, and ‘cetus’ for whale -and belong to the same family as dolphins and porpoises, the ‘Delphinidae’. There are two types (species) of pilot whale:
- The long-finned pilot whale, Figure 1; and,
- The short-finned pilot whale, Figure 2.
Whilst they are called whales, they are just a big species of dolphin. The terms whale and dolphin are somewhat woolly, and merely refer to the size (large = whale and small = dolphin). Porpoises, which are often confused with dolphin, belong to an entirely different group of animals that are all small.
Long-finned pilot whales
There are two further slightly differing types (subspecies) of the long-finned pilot whale. The term subspecies means that groups that live together (populations) in a particular geographical area may show differences either physically (shape, form, colour etc.) or genetically (in their genes), but are capable of breeding together successfully.
North Atlantic long-finned pilot whales are found in temperate (which means cooler) oceanic and coastal waters, where temperatures do not vary widely, of the North Atlantic Ocean, North Sea and the Mediterranean, Figure 1. Southern long-finned pilot whales live in the sub-polar (‘sub’ means north of the south pole, or south of the north pole) waters of the Pacific, South Atlantic and Indian Ocean.
Their bulky body is dark greyish-brown to black in colour with a long tail and round heads. Males have larger, and longer (more extended) heads, which can appear squarish when viewed from above. Their flippers are long, reaching 1/5 to 1/3 of their body length with strong angled leading edge resembling a sort of reverse ‘elbow’ and slender pointed tips. Male adults have a maximum recorded length of 7.6 m and weigh up to 2300 kg whilst females can reach 5.7 m and weigh 1300 kg. Newborn calves weigh only 75 kg (about the weight of a tall, fit dad) and are 1.7-1.8 m long.
Short-finned Pilot whales
Short-finned pilot whales (Figure 2.) are very similar to long-finned in appearance; however, their flippers are shorter and are sickle shaped (more curved), and the reverse elbow isn’t apparent. This is very difficult to tell underwater, so a way to guess which species observed, is to rely on their geographical location (which is rather unscientific). Short-finned pilot whales are distributed in deep offshore waters of warmer temperate to tropics regions, Figure 2.
To further complicate matters, the short-finned pilot whale has two ‘forms’ (i.e. not quite subspecies): Shiho-type and Naisa-type. The Shiho-type is found off northern Japan and in the eastern Pacific Ocean. Males can reach 7.2 m, weighing nearly 3600 kg whilst females reach 5.1 m in length. The Naisa-type is smaller with males and females only obtaining 5.25 m and 4 m in length respectively, and is present off southern Japan, southeast Asia, the Indian Ocean, and Hawai‘i.
This sociable marine mammal, travels in ‘pods’ of 10-20 individuals, which gather with other pods to form communities of 100 -1000 individuals. Like killer whales, calves stay with their mother for most of their lives.
For more information on marine mammals in general and information on a potential career in the subject, please see: www.osc.co.uk
Jefferson, A, Webber, MA & Pitman, RP (2008): Marine Mammals of the World. A Comprehensive Guide to their Identification. Academic Press/Elsevier, London, United Kingdom, pp. 193–199.