Long-finned pilot whale
Though long-finned pilot whales appear to be abundant, there have been no recent reliable estimates for the worldwide population, leading to their IUCN status of "Data Deficient".
he long-finned pilot whale (Globicephala melas) is a large species of oceanic dolphin. It shares the genus Globicephalawith the short-finned pilot whale (Globicephala macrorhynchus). Long-finned pilot whales are known as such because of their unusually long pectoral fins.
Despite its common name, the long-finned pilot whale is actually a large species of dolphin. The same is true of orcas and several other small whales. It has a bulbous forehead and is black or dark grey in colour with light grey or white markings on the throat and belly regions. This light grey patch found on the throat of pilot whales forms the shape of an anchor. Some individuals have other distinct markings such as a light coloured area behind dorsal fin, known as a saddle patch, as well as an upwards sweeping stripe just behind the eye. The dorsal fin is thick and falcate in nature, and is located about a third of the way down the length of the animal. The common name of this species is a reference to the pilot whale's long, sickle-shaped pectoral fins that are 15 to 20 percent of its total body length. It earned the nickname of pothead whale in some places because the shape of its heads reminded early whalers of black cooking pots. Being a toothed whale, pilot whales have a single blow hole.
The ranges of long-finned and short-finned pilot whales overlap in some areas of the world. As the difference between them is mainly distinguished by the length of the pectoral fins, it is extremely hard to tell the two species apart in these areas.
The long-finned pilot whale is one of the largest species of dolphin. The sexes are dimorphic, with females reaching lengths of up to 5.8 meters and 1,300 kg (1.3 long tons; 1.4 short tons), while males are significantly larger at up to 7.6 meters and 2,300 kg (2.3 long tons; 2.5 short tons).
An adult whale needs about 50 kg (110 lb) of food a day, which consists mostly of cephalopods and to a lesser amount of fish.
Females reach sexual maturity at about 3.7 m (12 ft) and 6 to 7 years of age. Males need about twice as long to reach sexual maturity at about 4.6 m (15 ft) and 12 years of age. There is evidence that some males may stay with their mothers after they reach sexual maturity. Mating is thought to occur when different groups meet up, and breeding within units is a rare occurrence. Gestation lasts approximately 12 to 15 months and calving occurs once every 3 to 5 years. Most calves are born in the summer, though some calving occurs throughout the year. Females have been observed to have calves as late as 55 years old, and lactate as late as 61.
Long-finned pilot whales are a very social species. They are usually seen in groups, which range in size from a couple of individuals to aggregations of over a thousand. However, 20 to 150 individuals are more commonly observed. Studies have shown that this species often forms small long-term social units made up of around 8-12 individuals.
These groups have been observed socializing with common bottlenose dolphins, Atlantic white-sided dolphins and Risso's dolphins.