Sperm Whale Fact Sheet
New York Status: Endangered
Federal Status: Endangered
The sperm whale is the largest of the toothed whales. It is the best known member of the whale family, generally being represented in toys and drawings. Moby Dick was a sperm whale. The most distinctive feature is the large, blunt head. This immense head contains spermaceti, a substance once widely used for ointments and candles. In Greek, the name translates loosely to "spouter with teeth on the bottom." This is indeed a good description. The single blowhole, located near the front and to the left side of the head, is angled forward about 45 degrees; spouts reach 20 feet into the air. The lower jaw contains 18-25 teeth which assist in eating squid and other cephalopods. Another trait is the absence of a dorsal fin. Instead, a large hump is present and behind it a series of bumps along the ridge of the back that extends to the large, notched, triangular flukes or tail flippers.
A male can be up to 70 feet (21 m) in length and weigh 59 tons (54 metric tons), while females reach 38 feet and weigh up to 15 tons. Overall, the body is dark blue to slate gray on the upper parts, lighter colored underneath, and white around the mouth. The brain of the sperm whale is the largest of any animal, averaging 15+ pounds and reaching up to 20 pounds. Squid is the primary food of the sperm whale, and much of its biology and behavior can be attributed to the search for this food item.
Members of this species do not travel in mixed groups of several males and females like other whales. Instead, harems are formed, consisting of a bull leading a group of adult females and their young. Adult males without a harem travel in bachelor groups, obtaining a harem only by fighting and defeating a bull that leads one. Pregnant or nursing females, calves, and some juveniles swim in "mixed groups" or "nursery schools" made up of about 25 individuals. After weaning, the males form "juvenile schools" then "bachelor schools" when reaching puberty at about 9 years of age. Although males are reproductively mature at about 19 years of age, they are not "socially mature" and cannot mate until they have acquired a harem.
Males compete with one another in early spring and summer for control of a group of mature females. A successful male will mate with all the females in his harem. Gestation lasts for about 15 months and the calf, which is 12-16 feet when born, nurses for about two years. After weaning, the female may not become pregnant again for nine months. Females reproduce only once every four years.
Distribution and Habitat
Sperm whales are found in all of the world's oceans, except for the Arctic region. In U. S. waters, they may be found from California and Hawaii north to the Bering Sea, and from Maine to the Gulf of Mexico.
They tend to prefer deep waters and generally remain along the edge of continental shelves in water 3,000-6,000 feet deep or further out to sea. When in open waters, this whale may dive for periods of more than one hour at depths of up to 8,000 feet.
Hunting was the primary cause of decline in this species. During the past two centuries, about one million sperm whales were killed. Current estimates reveal between 20,000-100,000 sperm whales remaining. Hunting is no longer a threat to this species and there are apparently no other threats currently existing.
Management and Research Needs
As with sea turtles, whales are often sighted in Long Island waters and occasionally become stranded or wash up dead on beaches, mainly along the south shore. A stranding network operated by the Riverhead Foundation for Marine Research and Preservation under contract to DEC alerts marine biologists to the possible rescue of stranded animals and the identification and autopsy of carcasses. The hotline number to report a stranding is (631) 369-9829.
Katona, S. K., V. Rough and D. T. Richardson. 1983. A field guide to the whales, porpoises, and seals of the Gulf of Maine and eastern Canada. Charles Scribner's Sons, New York. Pp. 123-129.
Leatherwood, S., K. K. Caldwell and H. E. Winn. 1976. Whales, dolphins, and porpoises of the western North Atlantic -- a guide to their identification. NOAA Tech. Report NMFS CIRC-396, Seattle, Washington.Pp.57-62.
Leatherwood, S. and R. R. Reeves. 1983. The Sierra Club handbook of whales and dolphins. Sierra Club Books, San Francisco.
Drawing by Elane Eckert