Many people associate large, dark-colored marine mammals with whales. This common perception often leads to confusion when encountering pilot whales, which, despite their name and imposing size, are not whales in the traditional sense. Understanding their true classification clarifies this widespread misconception.
Understanding Cetacean Classification
Marine mammals like whales, dolphins, and porpoises belong to the order Cetacea. This diverse group is divided into two suborders based on feeding mechanisms. The Mysticeti, or baleen whales, are filter feeders with baleen plates instead of teeth, which they use to strain small organisms like krill and plankton from the water. This suborder includes some of the largest animals, such as blue whales and humpback whales.
In contrast, the Odontoceti, or toothed whales, are a larger, more varied group, characterized by teeth and a single blowhole. It encompasses about 75 species, including sperm whales, beaked whales, and all dolphins and porpoises. Toothed whales use their teeth to hunt prey such as fish, squid, and even other marine mammals. Dolphins, specifically the family Delphinidae, are within this suborder, including species from the small Hector’s dolphin to the much larger orca.
Pilot Whales: Members of the Dolphin Family
Pilot whales are classified as dolphins, belonging to the oceanic dolphin family, Delphinidae. This might seem counterintuitive due to their common name and considerable size, comparable to some smaller whale species. However, their biological characteristics, such as teeth and a single blowhole, firmly align them with other dolphins and toothed whales. They are among the largest members of the dolphin family, second only to the orca.
The genus Globicephala contains two recognized species: the long-finned pilot whale (Globicephala melas) and the short-finned pilot whale (Globicephala macrorhynchus). Both species are widely distributed; long-finned pilot whales typically inhabit colder, temperate, and subpolar waters, whereas short-finned pilot whales prefer tropical and subtropical regions. Distinguishing between the two species often requires analyzing features like flipper length and skull characteristics.
Key Distinctions and Shared Traits
Pilot whales possess physical traits that contribute to their “whale-like” appearance and differentiate them from many other dolphin species. They have a robust, elongated body and a distinctive large, bulbous forehead (melon), which becomes particularly pronounced in adult males. Their coloration is typically dark gray to black, often with lighter patches on their underside. Adult long-finned pilot whales can reach lengths of up to 6.5 meters and weigh over 2,000 kilograms, while short-finned pilot whales can grow up to 7.2 meters and weigh as much as 3,200 kilograms.
Despite these distinguishing features, pilot whales share many characteristics with other dolphins. Like all toothed whales, they rely on echolocation to navigate, communicate, and locate prey. They are highly social animals, living in cohesive pods that can range from dozens to hundreds of individuals, often forming multi-generational family groups. Their diet primarily consists of squid and octopus, though they also consume fish. This blend of unique adaptations and shared dolphin traits highlights their distinct yet integral place within the diverse dolphin family.