The long-finned pilot whale, Globicephala melas, is a large species of oceanic dolphin, despite its common name. These highly intelligent and social creatures are known for their strong family bonds and cooperative behaviors. This species is one of two pilot whale types, the other being the short-finned, with subtle differences making them challenging to distinguish at sea.
Physical Characteristics and Distribution
Long-finned pilot whales possess a distinctive appearance, characterized by a robust, elongated body that is predominantly dark grey to black. They have a noticeable bulbous forehead, referred to as a melon, which can vary in shape with age and sex. Their long, sickle-shaped pectoral fins, which can measure up to a quarter of their body length, give the species its common name.
Adult males can reach lengths of over 6 meters and weigh up to 2.5 tonnes, making them significantly larger than females, who typically grow to about 5.5 meters and weigh around 1.32 tonnes. Most adults display pale grey or whitish markings, including an anchor-shaped patch on their throat and belly.
These whales inhabit cold temperate and subpolar waters, with distinct populations in the North Atlantic Ocean, including the North Sea and Mediterranean Sea, and throughout the Southern Hemisphere. They generally prefer deep, offshore waters, often found along the edges of continental shelves, though they can be seen in coastal areas in parts of the North Atlantic. Their movements are often associated with the distribution of their prey.
Behavior, Diet, and Social Structure
Long-finned pilot whales are highly social animals, forming stable, multi-generational pods that often consist of 20 to 100 individuals, though aggregations of over a thousand have been observed. These strong social bonds are often based on matrilineal structures, with older females frequently assisting in the care of calves. They communicate using a complex vocal repertoire that includes broadband echolocation clicks for hunting and navigation, alongside a variety of pulsed calls and whistles for social interaction.
Their diet primarily consists of squid, which they pursue during deep dives, often reaching depths of several hundred meters for periods of 10 to 16 minutes. Most foraging activity occurs at night at various depths.
Beyond feeding, these whales exhibit various surface behaviors like “logging” (where entire pods rest motionless at the surface), “spy-hopping” (which involves raising their head vertically out of the water), and occasional tail slapping or breaching. Long-finned pilot whales are also known for mass stranding events, where large groups come ashore, though the exact reasons for this behavior are not fully understood.
Conservation and Threats
The long-finned pilot whale is currently listed as “Least Concern” by the International Union for Conservation of Nature (IUCN) globally, with an estimated population of around 700,000 individuals worldwide. However, specific regional populations, such as those in the Mediterranean Sea, are classified as “Data Deficient” and face localized challenges.
These whales face several threats, with bycatch in fishing gear being a leading cause of injury and mortality. Entanglement in nets and lines can lead to drowning or severe injuries.
Noise pollution from human activities, including shipping and sonar, can disrupt their communication and echolocation, impacting their ability to navigate and find prey. Marine debris, such as plastic waste, poses a risk through ingestion or entanglement.
Chemical contaminants, which accumulate in their blubber through the food chain, can harm their immune and reproductive systems. Climate change also presents a long-term threat by altering ocean temperatures and chemistry, potentially impacting prey availability and habitat distribution.
Conservation efforts include implementing plans to reduce bycatch, researching the effects of ocean noise, and responding to stranding events to understand causes of mortality.