About Hawaiʻi’s Humpback Whales
Hawaiian name: Kohola
North Pacific humpback whales are a conservation success story. During the last twenty years, the north Pacific humpback whale population has grown from approximately 2,000 to more than 21,000 whales. During the winter breeding season, more than 12,000 humpback whales visit Hawaiian waters. People and humpbacks are increasing their shared use of the same marine habitats. HWF works to support appropriate management of potential conflicts.
How Hawaiʻi Wildlife Fund works to help Humpback Whales
Supports National Marine Sanctuary for whales
HWF worked to support the state’s acceptance of the Hawaiian Islands Humpback Whale National Marine Sanctuary in 1997, with cofounder Hannah Bernard serving on the Sanctuary Advisory Council in the 1990’s. HWF representatives continue to work with the Sanctuary Advisory Council and its working groups.
Teaches people about whales
HWF naturalists provide expert narration and interpretation on whale watches in the waters off Maui during the winter whale season. HWF partners with Kai Kanani Sailing to provide a teaching platform for students and professional presentations about marine life.
Conducts naturalist training courses
HWF conducts whale naturalist training classes each season as part of an education program at University of Hawaiʻi , Maui College
Humpback Whale Migration
North Pacific Humpback Whales leave the icy waters around Alaska during the fall, swimming practically non-stop for nearly 6 to 8 weeks before reaching their Hawaiian winter home, where they mate, give birth, and nurture their calves. Their annual migration of about 6,000 miles is one of the longest of any mammal.
Like most northern hemisphere baleen whales, humpbacks feed during the summer in sub-arctic regions and migrate to sub-tropical waters in winter to breed. Today, there may be as many as 26,000 humpbacks found in the North Pacific, classed as 4 distinct population segments (DPS).
- The Mexico DPS winters along the Pacific coast of Mexico and the Revillagigedo Islands, transits the Baja California Peninsula, and summers from California to the Aleutian Islands (Alaska). Protected status: Threatened under the US ESA.
- The Hawai’i DPS summers in southeast Alaska and Northern British Columbia, and winters in the waters around Hawaiʻi. Protected status: De-listed under the US ESA.
- The Western North Pacific DPS migrates between the Aleutian Islands area in the summer and islands south of Japan and the Philippines in the winter. Protected status: Endangered under the US ESA.
- The Central America DPS winters along the Pacific coast of Central America, including Costa Rica, Panama, Guatemala, El Salvador, Honduras, and Nicaragua, and summers off the West Coast of the United States and southern British Columbia. Protected status: Endangered under the US ESA.
Beginning in October, mother whales nursing their calves usually arrive first in Hawai’i. Then juveniles and mothers with their yearlings come, teaching them the migration, and often weaning them here in Hawaiian waters. The adult males arrive next, double the number of adult females who follow. Finally, the pregnant females arrive, after feeding up to the last minute in Alaska.
Humpbacks are distributed throughout the world’s oceans, although all populations were depleted by whaling from the mid-1800s and into this century. Before human exploitation, more than 15,000 humpbacks may have once roamed the North Pacific, but the numbers were reduced to less than 1,000 animals by 1965.
The waters surrounding the Hawaiian Islands are one of the most important humpback whale habitats. Humpbacks prefer two major areas in Hawaiʻi: the four-island region of Maui, Molokai, Lanai, and Kaho’olawe, and the Penguin Band, a tongue of shallow water extending 25 miles southwest of western Molokai. Within about the last 10 years, the whales have spread to the Big Island, Kauai and Oahu, between Koko Head and Sandy Beach, and to the North Shore.
In 1992, Congress recognized the importance of this habitat and designated critical areas as the Hawaiian Islands Humpback Whale National Marine Sanctuary. Humpbacks are no longer listed as an endangered species in Hawaiian waters, but are still protected by federal and state regulations.
Whale Behavior & Anatomy
One of the most thrilling behaviors to observe is the breach. With just a few strokes of their flukes, humpbacks can gain enough momentum to hurl their 30 ton, 45 foot bodies into the air, then crash back down with a thunderous splash! Theories abound as to why whales breach, from acoustic signaling to removal of barnacles to joyous play.
A powerful action often used in aggressive encounters, the tail slap occurs when the whale’s flukes are lifted clear out of the water and then brought down on the surface with a great resounding “crack!” Whales have been seen tail slapping repeatedly, more than 40 times! The width of their flukes can reach 15 feet and the underside is a distinctive as our own fingerprints.
Humpbacks have the longest pectoral fins of all whales, stretching up to 15 feet in length. These fins may be used to help maneuver the whale or signaling. A pectoral slap is created when a whale rolls on its side, raises its pectoral fin out of the water and forcefully slaps in down. At times a whale will turn completely on its back and slap both fins on the waters surface.
Dynamic displays of humpbacks performing courtship behaviors can be seen in the waters off the Hawaiian Islands. Males engage in competitive activities with each other for access to receptive females. Sometimes whales lunge aggressively at each other trying to displace one another resulting in superficial abrasions.
Mothers and calves are always seen close together: there is a powerful bond between them. Mothers often use their pectoral fins to caress and cradle their young and have been seen assisting their babies to the surface. Newborns are 12 to 15 feet long and can weigh 2 tons. Calves typically nurse for 8 to 12 months and can consume 80 gallons in a day. They can double their size in one year.
Although it may sound like groaning, screeching or creaking to us, humpbacks can produce sounds that are classified as true songs.
Songs are produced on the breeding grounds, and to date, singers observed have been identified as males. Researchers speculate that singing may play a role in attracting a mate, establishing a territory, or advertising availability.
Humpbacks in Hawaiʻi all sing virtually the same song. Their song is identical to that of the humpbacks breeding off the coasts of Mexico and Japan. The song changes every year, and it changes across the Pacific basin at virtually the same time! The song of the humpback is a mystery and a marvel: its purpose may be more complex than we can imagine.
The humpbacks don’t eat during their six months in the Hawaiian Islands. Hawaiʻi doesn’t offer their food, krill and herring. But, since the whales spent the summer in the north, doing nothing but eating, they are sustained by fat reserves in the winter.
Humpbacks sleep with half their brain at a time. Then they switch sides, and put the other half to sleep. The side that remains awake acts as a sentinel to protect the whale from threats, including sharks and boats.
Humpbacks can take about 39 days to travel the 3,200 miles from Alaska. They cruise an estimated 3 to 4 miles per hour, and are believed to swim 24 hours a day.