The pilot whale is a member of the dolphin family and is second only to the orca whale in size; males are much larger than females. Adult males reach a length 20 feet and can weigh up to 3 tons, adult females grow to 16 feet and weigh 1 ½ tons. There are two species of pilot whales, long finned and short finned; they are in the suborder of the Odontoceti the same as the killer whale which means they have teeth. Pilot whales are predominantly dark grey, brown or black, but have some light areas such as a grey saddle pitch behind the dorsal fins. The dorsal fin is set forward on the back and sweeps backwards. The body shape of a pilot whale is considerably more robust than most dolphins with a distinctive large, bulbous head; male long finned pilot whales develop more bulbous heads than females. The flippers are long and sickle shaped, and the tail stock is flattened from side to side and very deep.
Pilot whales generally take several breaths before diving for a few minutes, feeding dives may last over ten minutes. They are capable of diving to depths of 2,000 feet, but most dives are to a depth of 100-200 feet. Shallow dives tend to take place during the day while deeper ones take place at night. When making deep dives, pilot whales often make fast sprints to catch fast moving prey like squid. Short finned pilot whales foraging in the same depth range as sperm whales and beaked whales perform the more energetic hunting tactics in comparison. This involves an energetic burst of high speed swimming near the deep part of the dive and is usually followed by one or two buzzes which may indicate attempts to capture prey. This is unusual considering deep diving breath holding animals would be expected to swim slowly and steadily to conserve oxygen. It is possible that if pilot whales have a higher metabolic rate than other deep diving mammals to enable sprinting, this would be a factor influencing the relatively short diving period of pilot whales compared to other similarly sized marine mammals. This apparent lower diving capability has also been observed in long-finned pilot whales.
Pilot whales are primarily squid eaters, but will feed on fish as well. They are also highly social and some studies have found that both males and females remain in their mother’s pods, an unusual trait among mammals, but this is also found in some killer whale pods. Pilot whales have one of the longest birth intervals of the cetaceans, calving once every 3-5 years. Calves are approximately 6 feet long at birth and weigh about 250 pounds. Mating and calving in long-finned pilot whales peaks in the summer, though some calving occurs throughout the year. Both species live in groups of 10-30 but some groups may number 100 or more.