By Emily Cloyd
Geographic Range
The Pacific, or short-finned, pilot whale lives throughout the tropical and warm temperate waters of several oceans and associated seas and bays.
Biogeographic Regions:
indian ocean (native 
); atlantic ocean (native ); pacific ocean (native ).
Physical Description
(2640 to 6600 lbs; avg. 4620 lbs)
Pilot whales are jet black with a white patch on their chin, which may extend dorsally to the anus. They have a large, blubous head, with no beak and a slightly prominent upper lip. There are 7-9 large, conical teeth in each side of the uper and lower jaws. The flippers are short (about 1/5 of body length) and sickle-shaped. The dorsal fin is located further forward on the body than on any other cetacean. There is a median notch on the tail flukes. Sexual dimorphism occurs, with males reaching 5.9 m in length and 3000 kg and females growing to 4 m and 1200 kg.
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: male larger.
Reproduction
Calves are born at a 7 year interval, and a maximum of 4-5 calves are born in the mother's lifetime.
The breeding season is spread across the year.
Pilot whales are polygynous and, in breeding groups, there is a ratio of about 8 breeding females to 1 breeding male.
Mating systems:
polygynous .
Females reach sexual maturity at 7-12 years, males at 15-22 years. The breeding season is spread across the year, gestation lasts 11-13 months, and one calf is born. Weaning occurs at an average of 2 years, although has been known to extend to 6 or even 10 years (these longer periods are found in older mothers). Calves are born at a 7 year interval, and a maximum of 4-5 calves are born in the mother's lifetime. Female reproduction slows after about age 28 years and stops after age 40 years.
Key reproductive features:
iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
Behavior
Individuals aggregate in packs of 15-20, with all ages and both sexes, although groups of several hundred have been reported. While swimming, the group is led by a "pilot" and the rest of the pack follows by the signals of the pilot. When resting, pilot whales "log"--float stationary at the surface with their heads and dorsal fins exposed. Dives of 600 m have been reported.
Key behaviors:
natatorial ; motile ; social .
Food Habits
Pilot whales ingest about 45 kg of food per day. The main component of diet is squid, although small fish are also eaten.
Primary Diet:
carnivore (molluscivore ).
Animal Foods:
fish; mollusks.
Economic Importance for Humans: Negative
None known.
Economic Importance for Humans: Positive
Before international whaling laws were enacted, pilot whales were heavily hunted in the Faroe Islands and Japan for meat and oil. Kills of over 10,000 a year were reported by Japan, and over 100,000 in 300 years (1584-1883) in the Faroe Islands.
Conservation Status
Pilot whales are conservation dependent, and may be functionally extict in areas such as Newfoundland, but there are still sufficient numbers to support healthy populations of this species.
Other Comments
Pilot whales have been trained by the Navy to seek out and attach devices to experimental torpedoes that missed their mark. Also, because the entire group follows the lead "pilot" and responds to its distress calls, mass beachings are common among the species. This behavior is also implicated in the mass killings of these whales by hunters.
Contributors
Emily Cloyd (author), University of Michigan.
Phil Myers (editor), Museum of Zoology, University of Michigan.
