From November until May, the waters of Hawaii are visited by over 1000 humpback whales. These humpback whales have migrated to the warm waters of Hawaii from as far north as the Aleutian Islands of Alaska, as far east as Glacier Bay and as far south as the Farallon Islands off the coast of central California.
These humpback whales come to the warm waters of Hawaii where they breed, calve, and nurse their young.
This 3500-mile journey from their summer feeding areas takes between one and two months. It ensures that pregnant females and mothers with new-born calves spend the majority of their time in the relatively warm waters of Hawaii. Humpback calves are both conceived and born near the Hawaiian Islands. (The gestation period for the female is between 10-12 months.)In this first of a multi-part series, we will learn some basic information about Hawaii's annual winter guest.
What is a Humpback Whale?The humpback whale is the fifth largest of the world's great whales. Its scientific name, Megaptera novaeangliae, was given to it in 1781 by a German naturalist named Borowski, meaning "Big-Winged New Englander," referring to the size of the whale's huge tail fins and the fact that it was once widely sighted off the coast of New England. It's more common English name of humpback appears to come from the animal's tendency to round its back when diving.
The humpback whale is grayish-black, blue-black to dark black in color, with pale to white undersides that can show black markings that are varied according to the individual whale. It is with these markings, and particularly those found on the tail, that individual whales can be identified and the population and migratory patterns recorded.
Humpback whales also have flippers (or pectoral fins,) which are located on each side of their bodies. These are used to turn and steer. Whales are mammals, as are human beings, and these fins are actually modified forelimbs, with a bone structure similar to that of the human hand and arm.
When born, calves weigh an average of 3000 pounds and range from 10-16 feet in length. They can grow to between 40-52 feet in length, with the females being slightly larger than the males. A fully grown humpback weighs approximately one ton per foot, or about 84,000 - 90,000 pounds on average. Researchers believe humpbacks live between 40-60 years.
What do Humpback Whales Eat?
Humpback whales tend to feed within 150-160 feet of the water's surface. The Northern Pacific humpbacks consume plankton or small schooling fish such as mackerel and Pacific saury. The whales filter their food from large amounts of water containing fish that are brought into their mouths. Humpback whales have expandable ventral throat pleats which increase the capacity of their mouths during feeding.
Once all of the food is present in the mouth, the mouth is then closed and the water is pressed out. Meanwhile, the food is caught in what are called "baleen plates" and is then swallowed.
Baleen grows throughout a whale's life. Baleen is also called whalebone. Baleen consists of a series of stiff, flexible material that hangs from the upper jaw.
The inside of the baleen is edged with hairy plates that filter plankton, krill and small fish. Baleen is made of keratin (the same substance our fingernails and hair are made of).
Humpbacks can consume up to a ton of food in a day's time. Generally, however, they do not feed while in the waters of Hawaii, their winter breeding grounds.