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 6,000 humpbacks
found in the North Pacific, in three somewhat distinct populations.
- The eastern stock migrates primarily between the coasts of
Northern California in the summer and Mexico in the winter.
- The central stock summers in southeast Alaska and the Gulf of
Alaska and winters in the waters around Hawai'i.
- The western stock migrates between the Aleutian Islands area in
the summer and islands south of Japan in the winter.
Some exchange between these groups has been observed on the
Beginning in mid to late November, mother whales nursing their
calves usually arrive first in Hawai'i. Then juveniles and newly
weaned yearlings come. 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. As many as 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 Hawai'i: 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 listed as an endangered
species and are protected by federal and state regulations.
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