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HUMPBACK WHALE
Megaptera novaeangliae
meaning of scientific name: large-winged of New England
DESCRIPTION: The humpback whale was given its common
name because of the shape of its dorsal (back) fin and the
way it looks when the animal is diving. Its scientific name,
Megaptera, means, "large-winged" and refers to its
long, white, wing-like flippers that are often as long as
one-third of the animal's body length. Humpbacks are gray
or black, except for the flippers, parts of the chest and
belly, and sometimes the underside of the tail flukes. Each
whale has its own unique pattern on the underside of its tail
flukes, which can be used like"fingerprints" to
identify individual whales. Unique to humpbacks are wartlike
round protuberances (bumps or tubricales) that occur on the
head forward of the blowhole and on the edges of the flippers.
Humpbacks are baleen whales that have 14 to 35 long throat
pleats that expand when the whale takes in water while feeding.
Northern Hemisphere humpbacks reach an average length of 49
to 52 feet (15-16 m), and southern humpbacks reach 60 feet
(18 m). Females are generally larger than the males. The average
weight for a mature adult is 35 to 50 tons.
RANGE/HABITAT: Humpbacks are found in all oceans to
the edges of polar ice, and follow definite migration paths
from their summer feeding grounds to warmer waters in the
winter. There seem to be three distinct populations of Humpbacks
that do not interact with one another: one in the North Pacific,
one in the North Atlantic, and another in the Southern Hemisphere
(south of the equator). In the North Pacific, where their
populations reach 15,000, humpbacks feed in the summer along
the coast from California to Alaska. In the winter, they migrate
to breeding grounds off of Hawaii, Mexico, Costa Rica, and
Japan. The population in California migrates to Mexico and
Costa Rica, whereas the Alaskan population migrates to Hawaii.
BEHAVIOR: Acrobatic humpbacks regularly breach (jump
out of the water), stroke each other, and slap the water with
their flippers and flukes. Scientists believe these activities
are forms of communication because they create a great deal
of noise, which can be heard at long distances under water.
Humpbacks swim in groups or pods of up to a dozen at calving
grounds, and in smaller groups of three to four during migration.
Unlike other baleen whales, they can often be seen feeding
cooperatively.
In feeding, they use baleen plates to strain other small fish
such as krill or herring, and plankton out of the water. Their
270 to 400 baleen plates are dark and each is about two and
a half feet long. Humpbacks use several different feeding
methods. While "lunge feeding," they plow through
concentrated areas of food with their huge mouths open, swelling
with large quantities of food and water. During "bubble
net feeding," which is unique to humpback whales, one
or several whales blow a ring of bubbles from their blowholes
that encircle a school of krill or fish. The whales then swim
through the "net" with their mouths agape, taking
in large amounts of food.
Humpbacks are best known for their haunting vocalizations
or "singing." They have a rich repertoire that covers
many octaves and includes frequencies beyond the threshold
of human hearing. These songs, apparently sung by males, last
as long as 20 minutes, after which they are repeated, often
with slight changes. Each year, the song undergoes changes
from the year before, but all males sing the same song. When
a whale is singing, it floats suspended in the water, head
down and relatively motionless. Behavior such as dominance,
aggression, and mate attraction may be related to singing.
MATING AND BREEDING: Females give birth every two or more
years. Pregnancies last for 12 months. The calves nurse for
eight to eleven months. When weaned, the calves are 24-27
feet (8-9 m) long.
STATUS: Humpbacks are among the most endangered whales
and fewer than 10% of their original population remains. However,
in recent years, humpbacks have been observed more and more
frequently feeding along the California coast. Approximately
800 humpbacks feed along the California Coast in the Summer
and Fall.
AT THE MARINE MAMMAL CENTER: Probably the most famous
humpback whale is "Humphrey," who was rescued twice
by The Marine Mammal Center and other concerned groups. The
first rescue was in 1985, when he swam into San Francisco
Bay and then up the Sacramento River. Five years later, Humphrey
returned and became stuck on a mudflat in San Francisco Bay
near 3 COM Park. He was pulled off the mudflat with a large
cargo net and the help of a Coast Guard boat. Both times he
was successfully guided back to the Pacific Ocean using a
"sound net" in which people in a flotilla of boats
made unpleasant noises behind the whale by banging on steel
pipes, a Japanese fishing technique known as "oikami."
At the same time, the attractive sounds of humpback whales
preparing to feed were broadcast from a boat headed towards
the open ocean. Since leaving the San Francisco Bay in 1990
Humphrey has been seen only once, at the Farallon Islands
in 1991.
May be reprinted for scientific and educational purposes
Revised 2/02
Learn more about the following:
Blue Whale
Orca/Killer
Whale
Gray Whale
Beluga Whale
Dolphins
and Porpoises
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