THE HUMPBACK WHALE

The humpback whale is the fifth largest of the great whales.The humpback whale's Latin name, Megaptera novaeangliae, means "Big wings of New England", and refers to the 15 foot pectoral (side) fins or "flippers" which protrude from either side of the body.

Females are slightly larger than the males in the adult stage, reaching 45 and 42 feet respectively. A mature humpback whale may weigh up to a ton per foot, or nearly 40 tons (80,000 lbs) when fully mature. Calves range from 10 to 15 feet in length, and average 3,000 pounds at birth.

Physical Description: The head of a humpback whale is large in proportion to its body, comprising nearly one-third the whale's entire body mass. The mouth line runs high along the entire length of the head, dropping sharply just before the eyes. The eyes are located one on either side of the head.

Each eye is about the size of a large orange, and is found just above the end of the mouth line. The eyes bulge slightly from the orbital cavity (eye socket) and are generally brown in color with a kidney-shaped pupil.

The ear of a humpback is located just behind and below the eye. The absence of an external ear flap makes it nearly impossible to detect the tiny half-inch ear slit. The nares, or blowholes, through which the whale breathes air, are located near the center of the head, and slightly further back than the eyes. There is an elevated area in front of the blowholes, called the splash guard, or blowhole crest, which prevents water from pouring into the blowholes when the whale breathes in.

A humpback whale's head is adorned with curious knobs, which are called tubercles, or sensory nodules. These golf-ball sized bumps are located on the humpback's upper and lower jaws, and along the lips. Each tubercle contains a hair follicle, with a single light gray vibrissa, usually about 0.5 inch long. The exact function of the tubercles is unknown, but it is generally believed they provide some sensory capability, perhaps through sensitivity to either vibration or temperature.

A series of prominent grooves is located along the whale's throat, stretching from the tip of the lower jaw all the way back to the navel. These ventral pleats, which may number from 12 to 30, allow the animal to expand its mouth (to nearly three times the body's normal girth!) during feeding, but yet remain relatively stream-lined while swimming about at other times.

The torpedo shape of the whale may assist in its long migrations (upwards of 7,000 mile round-trip between the summer feeding areas and the winter breeding grounds in Hawaii).

Humpbacks may occasionally swim at speeds in excess of 15 miles per hour for brief periods. This would probably not be possible if their mouth was permanently enlarged to its full extent.

Photo Identification: The identification of individual animals is an important way to determine life histories, social organization, migratory behavior, and abundance patterns of populations of humpback whales. Although humpback whales have a variety of individually unique markings and coloration patterns, the underneath surface of the tail flukes provides the best opportunity for identifying individuals. When a humpback dives deeply, following a series of respiration surfacings, it will frequently lift the tail flukes straight out of the water in a fluke-up dive, revealing the coloration and marking/scar pattern on the ventral surface.

Songs of the humpback whales: Humpbacks produce a wide array of sounds, including the highest and lowest frequencies humans can hear, with an extraordinary range of tonal qualities. How humpbacks create these sounds is unknown since they do not have functional vocal cords. Some evidence suggests that the sounds are produced by various valves, muscles, and a series of blind sacs found branching off the respiratory tract. Most of the sounds produced by male humpbacks form long, complex patterns or songs, which are often repeated for hours.

The humpback is the only great whale known to sing long and complex songs. The song is in a constant state of evolution. As the season progresses, themes may be introduced or changed. In a given area, such as Hawaii, all the whales are singing the same song, with each singer changing its song as the breeding season progresses. As a result, the song heard at the end of the season is quite different from the song heard at the beginning. Little or no singing takes place during the summer feeding months in northern waters and further change to the song does not appear to occur. When the whales return to the breeding grounds the following winter, they resume singing the version popular at the end of the previous breeding season. The song continues to change as time goes by, until after a number of years the song is hardly recognizable when compared to its earlier form. Since singing occurs primarily during the breeding season, it is thought the song serves a reproductive function. The song may serve to attract females, scare away other males, or maintain a distance between singers.

The humpback whale is an endangered species that has been protected from whaling since 1966 in the North Pacific, and since 1963 in the South Pacific. The North Pacific stock is estimated to be in the order of 3,500 animals, with specific estimates ranging between 6,000 and 8,000. About 60% are thought to winter in Hawaii each year, with the remaining 1,500 going in roughly equivalent numbers to areas off the Baja coast of Mexico, or areas southeast of Japan.

NOTE: Readers might be interested in reading HAWAII'S HUMPBACK WHALES by Gregory Kaufman, from which a lot of the information on this page is excerpted.