By Michael Kuo
Geographic Range
The distribution of this species is limited to the cooler water of the globe. The northern and southern populations do not meet, mix, and interbreed because they are separated by a wide band of warm tropical water.
Biogeographic Regions:
nearctic
(native
); atlantic ocean
(native
).
Physical Description
Long-finned pilot whale are black-colored whales with a white belly along with inflated, spherical head and a robust body with the long tapering trunk. There is no constriction at the neck and the body is quite cylindrical from the head backward to the region of the dorsal fin. The dorsal fin has a long base; it is low, directed backward, and is set far foward on the body. The tail is long, high, laterally compressed, and bears a keel on both its upper and lower ridges. The species has 8 to 13 teeth in each of the four jawbones and a flipper which is 1/5 of the body length. The average length of males is 19.7 ft. and a maximum of possibly 26ft. (8 meters) or more. The female will measure from 5 to 6 meters (16.4 to 19.7 ft.) or more. The age of pilot whales are determined by counting growth-layers in the dentine of the teeth. Deposition of dentine however ends with complete filling of the pulp-cavity at ages of 10-20 years. Cemental layers continue to be laid down but narrow, allowing less accurate age determination.
Some key physical features:
endothermic
; bilateral symmetry
.
Reproduction
Each adult female probably raises one calf about every three years
The adults mate in February and March.
Female mature sexually at 6 to 7 years, male not until about 12 years. As result there is an excess of mature females and the species is undoubtedly polygynous.
Mating systems:
polygynous
.
The adults mate in February and March in warm water and the young are born between July and October, 15 to 16 months later, in cooler water; thereafter the young are nursed for about 20 months. The length of lactation is estimated at 21 to 22 months. Since pregnancy and lactation rarely overlap, and a period of ovulation occurs at the end of lactation, the duration of the whole reproductive cycle is deduced to be some 40 months. So, each adult female probably raises one calf about every three years.
Key reproductive features:
iteroparous
; seasonal breeding
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; viviparous
.
The young, when born, are reported as a brownish to tan-gray color, and will measure about 1.4 meters (55in.) or more in length. They are toothless and will remain with their mother for most of the next two years.
Parental investment:
pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (protecting: female); extended period of juvenile learning.
Behavior
This species is a gregarious species and usually travel in a small group of 4 to 6 individuals. They are occasionally see in herds of 50 or more and, on some occasions, they will gather by the hundreds. They are not particularly friendly with ships and do not ride the bow waves of vessels. They have an inborn fear of the killer whale and will come into shallow water and beach themselves of other escape routes are not available. No instances have been reported of killer whales associated with pilot whales either inshore or offshore during the summer. Killer pass through eastern Newfoundland waters in June, apparently following the baleen whales, particularly minke whales, which migrate through earlier and range considerably to the northward of the pilot whales. Whether predation, either from killer or sharks, occurs in the winter months cannot be decided except by direct observation. The pilot whale pods are composed of single, huge families come as no real surprise, given the remarkable way in which they can be herded. It was unexpected that neither males nor females disperse. Pilot whales, it appears, remain in the pod in which they were born for their entire lives.
Key behaviors:
natatorial
; motile
; social
.
Food Habits
The diet of this species consists mostly of squid and cod. They eat a variety of fishes as alternatives. The average amount of food ingested at a meal is about 14 kg (30lb). They use echolocation to help them locate a food source. The bulbous forehead houses the pilot's melon, core organ of its sonarlike echolocation system. They are known to dive to depth of 600 meters (1967 ft.) or more during tests and also pursuing squid.
Primary Diet:
carnivore
(molluscivore
).
Animal Foods:
fish; mollusks.
Economic Importance for Humans: Positive
This small whale has supported a whale harvest from very ancient time. When herds have appeared along a coastline, the inhabitants have gone to sea in small whale harvest was carried on in Newfoundland, western Greenland, Iceland, many islands north of England, and on the coasts of Peru and Chile. These catches have declined in size and are now of less importance. Each whale would yield 40 gallons of blubber oil and 2 gallons of head and jaw oil.
Conservation Status
Pilot whales are taken in an intensive whale harvest in Trinity Bay, eastern Newfoundland. Reduction in the number of whales being captured each year suggests that whale harvest may be over-exploited and fishing should be restained.
Other Comments
In oldend times, this species was used in Europe to locate schools of herring and was therefore called the "pilot" whale.
Contributors
Michael Kuo (author), University of Michigan.
