Pacific Whale Foundation's Facts
The humpback whale is the fifth largest of the world's
great whales. Distinct populations of humpback whales
are found in each of the world's oceans. Newborn calves,
weighing an average of 1.5 tons, range from 10 to
16 feet in length. Males may reach 43 feet in length,
while females are slightly larger, averaging 45 feet.
A mature humpback weighs up to one ton per foot, or
about 85,000 - 90,000 pounds.
Researchers believe humpbacks live approximately 40
- 60 years, grayish-black in color, humpback whales
have white markings that are distinct to each individual.
A whale swims by moving its tail or fins up and down
(fish move their tails from side to side).
The flippers or pectoral fins, located on each side
of the whale, are used to turn and steer. These fins
are actually modified forelimbs, with a bone structure
similar to that of the human hand and arm. Humpback
whales breathe through a double blowhole located on
top of their head.
A Humpback's head has tubercles (fleshy knobs) along
the upper and lower jaws. Each turbercle has a single
hair and is believed to enhance sensory ability. Expandable
ventral throat pleats increase the capacity of the
mouth during feeding.
The humpback's scientific name, Megaptera novaeangliae
("Great Wings of New England") refers to its huge
fifteen-foot pectoral fins. The name "hump-back" coined
by whalers, probably resulted from the appearance
of the arching of the caudal peduncle while diving,
coupled with the prominent dorsal fin.
In Hawaii, the word kohola refers to the general category
of whale; there is no specific name for humpback.
Migration and Distribution
North Pacific humpbacks spend their summer in temperate
waters from the Aleutian Islands of Alaska to the
Farallon Islands off the coast of central California.
During the colder winter months, November to May,
the majority of the North Pacific stock is found in
the warm waters of Hawaii where they breed, calve,
and nurse their young.
The remaining animals are found off the coast of Baja
California, Mexico, and throughout the islands of
south Japan. In the South Pacific, humpbacks feed
near Antarctica in the austral summer, November to
May, and spend the austral winter, June to October,
breeding off east Australia and South Pacific Islands.
Consequently, researchers believe northern and southern
stocks do not intermingle.
Humpbacks are not fast swimmers. While they can attain
speeds of 20 mph for brief periods, they average three
to six mph during migration. How long it takes to
travel the more than 3,500 miles between the feeding
and breeding areas is not known. At least one animal
traveled the distance in less than 80 days.
Timing of the migratory cycle ensures that pregnant
females and mothers with new-born calves spend the
majority of their time in relatively warm water. Research
indicates that humpbacks may use acoustical cues,
currents and temperature changes, and even the earth's
magnetic field to "hone in" on their breeding and
Some movement of individual humpback whales between
breeding areas have been documented. Whales photographed
in Hawaii in one year have been observed in Mexico
and south of Japan in other years.
One whale was observed in both Mexico and Hawaii during
the same winter!
Humpback calves are both conceived and born near Hawaii;
the gestation period is 10-12 months. Although sightings
of calves are common during the winter, no well-documented
evidence of an actual birth exists. After a calf is
born, it's mother will remain close to shore, resting
and nursing her newborn.
Calves survive on their mother's fat-rich milk for
six to eight months. They grow at an astounding rate,
nearly doubling in length in their first year. Often
mothers and calves are accompanied by a third whale
called an escort. The escort whale, assumed to be
a sexually active male, remains with the mother and
calf for less than a day, with most associations lasting
a few hours. Males and females do not form long-term
Although it has never been documented, mating may
occur in association with large surface-active groups
of whales which include a single receptive female
who is pursued by a number of males. Competition for
the female involves a variety of intensely aggressive
behaviors that may occasionally escalate and result
Communication and Song
Humpback whales produce a wide array of sounds, including
the highest and lowest frequencies humans can hear.
Humpbacks do not have functional vocal cords; evidence
suggests that their sounds are produced by valves
and muscles in a series of blind sacs which branch
off in the respiratory tract.
During the winter breeding season, male humpbacks
produce long complex patterns of sound called "songs"
which they repeat for extended periods. Discrete notes
occur in patterned sequences that make up a phrase.
Usually uniform in duration, phrases may contain repeated
sounds. A consecutive group of phrases constitutes
a theme. Although a given theme may vary in the number
of phrases it contains, its sequence is always the
same. Similarly, the sequence in which themes occur
is always the same, although some themes may be left
out. A predictable series of themes forms a song.
Researchers believe the song may serve to attract
females, to scare away other males, or to maintain
the distance between singers. A song generally lasts
between six and eighteen minutes. A male may repeat
his song many times with a minimum of pause.
An analysis of songs collected from Mexico, Hawaii,
and Japan within the same season indicates virtually
all North Pacific Humpbacks sing nearly the same song.
As the season progresses, small changes occur in the
song. When the whales return to the breeding grounds
the following winter, they sing the version popular
at the end of the previous breeding season.
When a humpback dives, it may lift its tail out of
the water, allowing observers to view a unique pigmentation
pattern on its underside. Each humpback can be individually
identified by a photograph of this "natural tag".
These fluke identification photos can be catalogued
with information about the date and time of the sighting,
pod composition, travel direction, and presence /
absence of a calf. More than two thousand humpback
whales have been individually identified in the North
As whales are reindentified on subsequent occasions,
these resights provide important insight into migratory
routes, population estimates, social structures, behavior,
longevity and reproductive rates. Photoidentification
and other benign research techniques (such as acoustic
monitoring, genetic analysis, and satellite tracking)
remove the need to kill endangered whales in order
to understand them.
The following variety of behaviors, most visible from
boats and shoreline lookouts, are high energy activities
that may serve a number of social functions. They
must be interpreted in the full context of the season
and location in which it occurs to understand their
significance and purpose.
The normal pattern of exhalation and inhalation at
the surface. This term refers to both the act of breathing
and the cloud of water condensation produced above
the animals head during the process of exhalation.
Round Out / Peduncle Arch:
The whale begins a diving descent by arching its body
slightly while rolling ahead at the surface (round
out). As the caudal peduncle appears, the whale may
arch high above the water, perhaps in an attempt to
dive more deeply (peduncle arch).
Fluke Up / Fluke Down Dive:
Following a peduncle arch, the humpback will usually
bring its flukes above the surface of the water. In
a fluke up dive, the flukes will be brought straight
up into the air, exposing the entire ventral surface,
and displays the unque pattern of markings found on
each whale. In a fluke down dive, the flukes are brought
clear of the water but remain turned down, so that
the ventral surface is not exposed.
Humpbacks frequently roll at the surface, slapping
their pectoral fins against the water. Humpbacks also
lay on their back waving both fins in the air at the
same time before slapping them on top of the water.
The whale rises relatively straight up out of the
water rather slowly, maintains its head above the
surface to just below the eye, often turns 90-180
degrees on its longitudinal axis, and then slips back
below the surface.
This forceful slapping of the flukes against the surface
of the water can be carried out while the whale is
lying either dorsal up or ventral up in the water.
An aggressive behavior n which the rear portion of
the body, including the caudal peduncle and the flukes,
is thrown up out of the water and then brought down
sideways, either on the surface of the water or on
top of another whale.
Lunging head-first out of the water, the whale pounds
its massive, sometimes partially engorged mouth on
the water's surface. The head can rise 20 feet above
the water at the peak of the display.
The whale propels itself out of the water, generally
clearing the surface with two-thirds of its body or
more. As the whale rises above the water, it throws
one pectoral fin out to the side and turns in the
air about its longitudinal axis.
North Pacific humpback whales feed on small schooling
fish (e.g., herring, smelt and sand lance) during
the summer months when fish stocks are most productive.
South Pacific humpbacks feed primarily on krill near
Humpbacks can consume nearly a ton of food in a day's
time. During their summer feeding cycle, they store
enough energy to last the rest of the year.
Generally, they do not feed on the winter breeding
grounds, although limited evidence suggests they may
feed opportunistically en route and near their breeding
Prior to extensive commercial whaling, the North Pacific
humpback whale stock may have numbered 15,000 animals.
Commercial whaling reduced the population to fewer
than 1,000 by 1966, prompting international protection.
In the early 1970's, humpbacks were afforded additional
protection in U.S. waters by the Marine Mammal Protection
Act and the Endangered Species Act. By 1993, the North
Pacific stock was estimated to number 2,500 to 3,000
Scientists believe that nearly two-thirds of the stock
migrates to Hawaii each winter to engage in reproductive
activities. Although the North Pacific humpback population
has shown initial signs of recovery since 1966, they
remain an endangered species.
Because Extinction is Forever
Pioneers in whale research, the Pacific Whale Foundation
has been a leader in the fight to save humpback whales
from extinction since 1990. A non-profit, tax exempt
501 (c)(3) organization, the Pacific Whale Foundation
actively studies whales and dolphins throughout the
Pacific to explore the factors than ensure their survival
Humpback whales are still threatened by commercial
whaling, as well as commercial and acoustic pollution,
marine debris, destructive fishing practices and the
loss of habitat through human encroachment. Pacific
Whale Foundation urges you to become active in the
fight to protect humpback whales and their precious
For more information on how you can become involved
with the Pacific Whale Foundation's research, conservation
and education programs go to: http://pacificwhale.org/index.html
Pacific Whale Foundation's Hawaiian Humpback Whale
Project Title: Recovery of Hawaiian Humpback Whales
Research Site: Maui, Hawaii
The humpback whale (Megaptera novaeangliae)
migrates each winter from high latitude feeding grounds
to wintering areas closer to the equator. The behavior
of the whales while in the wintering areas and status
of their reproductive physiology indicate that breeding
and calving activities are dominant on the wintering
The Hawaiian archipelago is thought to comprise the
largest population of the three known breeding grounds
for the Northern Pacific humpback stock. A second
breeding ground is found in Mexican waters around
the Baja Peninsula, Gulf of California, and Islas
de Revillagigedo. The third is found south of Japan,
among the Ogasawara, Ryukyuan and Marianas Islands.
Adult humpbacks vary in length from 40-50 feet, the
females being slightly longer than the males, and
weigh up to 55 tons. Their coloration is generally
black dorsally and white ventrally, with many possible
variations. Photographs of the variations in pigmentation
pattern of the tail-flukes, differences in lateral
body markings, variation in the shapes of the dorsal
fins and the disposition of the body scars all provide
the opportunity to individually identify unique whales.
Humpback whales feed from June to September on euphausiids
(see note below) and schooling fish in Alaska. Estimates
of Australian humpback migratory speeds range from
1.7 to 2.0 kilometers per hour (0.1 to 1.1kt). Investigations
in Hawaiian waters yielded a 67 day resight between
Alaska and Hawaii supporting the estimated speed of
1.7 (0.9kt) kilometers per hour.
The animals begin arriving in Hawaii as early as late
October. The peak of the annual migration occurs in
February and March while some animals delay departure
until late May or early June. Animals appear to remain
on the wintering grounds for six to eight weeks.
The population of North Pacific humpbacks has recently
been estimated to number about 6,000 individuals,
with about 4,000 whales using the Hawaiian Islands.
Because whales move throughout the islands and between
the three different breeding grounds, earlier estimates
of the abundance of humpbacks in the North Pacific
were much lower.
Humpback whales sing complex songs which are subject
to continual and gradual change during the winter
breeding months. Humpbacks sing distinct songs in
different geographical areas, e.g., songs from the
Northern Atlantic and the Eastern Pacific differ greatly,
as do songs from the North Pacific and South Pacific.
Within a region, song changes during the course of
a winter season, but at any given time, singers within
the region engage in the same or similar rendition.
The exact function of the song remains speculative:
we do know that only males have been identified as
singers, and we know that singing peaks during the
winter months, although portions of song have been
heard on the summer feeding grounds and along the
migratory pathways. There is a general agreement that,
because of the correlation between song production
and gonadal activity, the song is associated with
Responses of whales to approaches by boats
A collaborative study between PWF and Albright College
in Reading, Pennsylvania documented near-shore observations
of the behaviors of humpback whales in the vicinity
of boat activity near an elevated shore-spotting station
at Olowalu, Maui.
Observers tracked the movement patterns of individual
whales, or pods of whales, using binoculars and a
surveyor's transit (theodolite). Whales were observed
before, during, and after being approached within
.5 mi by one or more boats. Data were collected on
repiration intervals, location of boats and whales,
and surface behaviors. Thirty-four observation episodes
were selected for statistical analysis.
The results indicate that boats had an impact on whale
movement and behavior not only while within .5 mi
of whales, but also for up to 20 minutes after leaving
the area. The observed whales reduced the number of
surface behaviors in the presence of boats, engaged
in larger changes in direction, and spent more time
underwater, when boats were present. After boats left,
whales showed evidence of a recovery period, spending
significantly longer time under water in the first
ten minutes after the boats left, than in the second
ten minutes. There was also a gradual recovery of
higher frequencies of surface activities.
The study points out the need to consider the cumulative
impacts of successive vessels on whales, and the potential
importance of a "time out" for the whales following
a boat-whale encounter.
Copyright 1998 Pacific Whale Foundation