off northeastern Florida (top left and right) and off Cape Cod, Mass.
(bottom left) clearly showing the narrow upper jaw, the bonnet, and the
widely separated blowholes. In the photo on the bottom left note the
extremely long baleen plates, characteristic of bowhead and right
whales. (_Photos by N. Fain, courtesy of Marineland of Florida (top left
and right); and W. A. Watkins (bottom left)._)]
[Illustration: Figure 50.--Right whales frequently throw their tail
flukes high into the air and then slip nearly vertically beneath the
surface. Note that the rear margin of the flukes of this species, unlike
that of the humpback whale, is smooth, broad, and concaved distinctly
towards a deep fluke notch. (_Photos from the northern North Atlantic by
K. C. Balcomb (a-g) and off northeastern Florida by N. Fain, courtesy of
Marineland of Florida (h)._)]
[Illustration: Figure 51.--A stranded right whale at Narragensett Bay,
R.I. Note the narrow, highly arched lower jaw; the extremely long,
narrow baleen plates, reaching lengths of 6.5 feet (2.0 m), or more; and
the bonnet (the protuberance near the tip of the upper jaw). (_Photo
from U.S. National Museum, courtesy of J. G. Mead._)]
[Illustration: Figure 52.--A ventral view of a harpooned female right
whale at Newfoundland. Note that this species, like the bowhead, lacks
the series of ventral grooves which characterize all other baleen whales
of the western North Atlantic. Note also the absence of the vest of
white on the chin, a feature which is characteristic of the bowhead
whale. Some right whales, however, do have extensive regions of white on
the ventral surface, including the chin. (_Photo from U.S. National
Museum, courtesy of J. G. Mead._)]
SPERM WHALE (T)
_Physeter catodon_ Linnaeus 1758
Other Common Names
Cachalot, Sea Wap (St. Vincent).
Description
Male sperm whales have been reported to reach a length of 69 feet (20.9
m), though today individuals larger than 50 feet (15.2 m) are rare.
Females are much smaller, rarely exceeding 38 feet (11.6 m).
A sperm whale is among the easiest of whales to identify at sea even
when comparatively little of the animal is visible. It has a huge head,
which comprises from a fourth to a third of the animal's total length.
(The proportion is considerably higher for males than for females.) The
blunted "squarish" snout, which may project up to 5 feet (1.5 m) beyond
the tip of the lower jaw, houses a large reservoir containing a
high-quality oil called spermaceti.
The single blowhole is located well to the left of the midline and far
forward on the head. As a consequence the small bushy blow, usually less
than 8 feet (2.4 m), emerges forward at a sharp angle from the head and
towards the left. Under good wind conditions this feature alone may
permit positive identification of sperm whales even at considerable
distances.
Sperm whales have a distinct dorsal hump, usually rounded in its
appearance about two-thirds of the way back from the tip of the snout.
Immediately behind the hump is a series of knuckles or crenulations
along the midline. This hump and the crenulations are clearly visible
when the animals arch the tail before beginning a dive. There is a
ventral keel, which may also be visible as animals "sound" (dive). The
flukes of sperm whales are broad and triangular in shape, are not
concaved, but are deeply notched on the rear margin.
Sperm whales usually are dark brownish gray in color. The body has a
"corrugated" or "shriveled" appearance. The belly and the front of the
head may be grayish to off-white. The skin around the mouth,
particularly near the corners, is white. The undersides of the flukes
and flippers vary in color through numerous shades of browns and
brownish grays.
Natural History Notes
Sperm whales may dive to depths in excess of 3,270 feet (996.7 m) for
periods of an hour or more. As do most whales upon surfacing from a deep
dive, sperm whales emit a single explosive blow and then, depending on
the length of the dive, may remain on the surface for over 10 min and
blow more than 50 times before beginning the next dive. Shorter periods
on the surface and fewer blows are more common. Females may dive and
remain on the surface for shorter periods of time than males. When
beginning a deep dive, sperm whales throw their broad triangular flukes,
dark on the undersides, high into the air.
Sperm whales may be found singly or in groups of up to 35 or 40
individuals. Older males are usually solitary except during the breeding
season. During the remainder of the year large groups may be bachelor
bulls (sexually inactive males) or nursery schools containing females
and juveniles of both sexes. Sperm whales are seldom found in less than
600 feet (182.9 m) of water.
Sperm whales feed primarily on squid but may occasionally also take
octopuses and a variety of fishes.
May Be Confused With
Because of their distinctive head shape and blow, sperm whales are
unlikely to be confused with any other species when they can be closely
examined. If only the back and tail flukes are seen, however, sperm
whales may somewhat resemble humpback whales. Both species arch the back
when beginning a dive, raising the fin or hump, and both throw the tail
flukes. The most distinctive differences between the two species are
tabularized on p. 40.
At sea the head of a sperm whale may also somewhat resemble that of an
adult male northern bottlenosed whale, but this latter species is
lighter brown in color, has a distinct beak and a prominent dorsal fin,
and is rarely found south of lat. 42 deg.N. In addition, the blowhole of the
northern bottlenosed whale is located well back on the head and not--as
in the sperm whale--on the front.
Distribution
Sperm whales are widely distributed in oceanic areas of the western
North Atlantic. They may be encountered from Venezuela north at least as
far as the Davis Straits, though they apparently avoid the polar ice
fields. Distribution and migrations vary between males and females.
Males range farther to the north, while females and immature males
remain between lat. 30 deg. and 50 deg.N. Both groups shift northward during
spring and summer and return to southern portions of their range in the
fall. Adult males arrive off the New England coast in August. Those
reaching the Newfoundland and Labrador coasts arrive from the deep sea,
perhaps following the slope contours, in August and September. Males are
abundant as far north as southeast Greenland and Iceland in summer. Some
animals remain as late as November, but the majority migrate south to
temperate or tropical waters in the early fall.
Historically the primary grounds in the western North Atlantic were
those in all the following areas: the Grand Banks just southeast of the
southern Grand Banks from lat. 30 deg. to 40 deg.N and long. 35 deg. to 55 deg.W, off
the Carolinas, around the Bahamas, around many of the West Indies, and
in the southwestern Caribbean.
Stranded Specimens
Stranded sperm whales should be easy to identify. The very narrow
underslung jaw contains from 18 to 25 functional teeth, which fit into
sockets in the upper jaw. The huge, distinctly box-shaped head and the
position of the single blowhole to the left front of the head are
unmistakable clues.
[Illustration: Figure 53.--An aerial view of 21 sperm whales, including
two young calves and several large males, off Japan. Even from an
aircraft, the position of the blowhole and the body shape clearly mark
these animals as sperm whales. (_Photos by Suisan Koku Company, courtesy
of T. Kasuya._)]
[Illustration: Figure 54.--A side view of a sperm whale in the West
Indies, showing the distinctive blow. Note that the spout projects
obliquely forward from the blowhole, which is displaced to the left
front of the head. (_Photo by H. E. Winn._)]
[Illustration: Figure 55.--Note the distinctive body shape and the
position of the blowhole of these swimming sperm whales, and, in the
animal on the left, the broad tail flukes. (_Photos from the North
Atlantic by S. Green (left) and from the North Pacific by S. Ohsumi
(right)._)]
[Illustration: Figure 56.--A sperm whale mother and calf off Baja
California, showing the distinct dorsal hump and the extremely long
head. In the bottom photo, from the West Indies, note the dorsal hump
and the crenulations of bumps which follow it. Both the hump and the
crenulations may be visible as the animal arches its tail to begin a
deep dive. Note also the wrinkled appearance of the body. (_Photo by K.
C. Balcomb (top) and H. E. Winn (bottom)._)]
[Illustration: Figure 57.--Sperm whales often show their broad tail
flukes as they begin long dives, which may last over an hour and take
them to depths of several thousand feet or more. Note the smooth rear
margin and the nearly triangular shape of the flukes. (_Photo from off
Baja California by K. C. Balcomb._)]
[Illustration: Figure 58.--A stranded infant male sperm whale at
Melbourne Beach, Fla. (top) and a male adult sperm whale on the deck of
a whaling ship in the Pacific (bottom). Note the bulging forehead, the
narrow, underslung lower jaw, the white coloration around the mouth,
particularly at the corners, and the wrinkled appearance of the body. In
the bottom photo note also the whitish region on the belly. (_Photos by
P. Winfield (top) and Japanese Whales Research Institute, courtesy of H.
Omura (bottom)._)]
[Illustration: Figure 59.--The narrow lower jaw of a sperm whale
contains from 18 to 25 large functional teeth, which fit neatly into
sockets in the upper jaw. Occasionally, the upper jaw also contains some
teeth. (_Photo from the North Pacific by Japanese Whales Research
Institute, courtesy of H. Omura._)]
[Illustration: Figure 60.--The throat and lower jaw of a sperm whale on
the deck of an eastern Canadian whaling station, showing the numerous
short throat grooves, which are most clearly evident on adult animals.
(_Photo by J. G. Mead._)]
[Illustration: Figure 61.--Detail of the broad, paddle-shaped flipper of
a sperm whale from the North Pacific. (_Photo from Japanese Whales
Research Institute, courtesy of H. Omura._)]
Medium-sized Whales With a Dorsal Fin
MINKE WHALE (B)
_Balaenoptera acutorostrata_ Lacepede 1804
Other Common Names
Little piked whale, lesser rorqual, little firmer, sharp-headed finner,
grampus (Newfoundland), gibord (Quebec).
Description
Minke whales are the smallest baleen whale species in the northern
hemisphere, reaching maximum lengths of just over 30 feet (9.1 m). One
of the most distinctive features of this species is an extremely narrow,
pointed, distinctly triangular rostrum with a single head ridge, similar
to but much sharper than that of the fin whale (hence the common name
"sharp-headed finner"). Minke whales have a tall, falcate dorsal fin
located in the latter third of the back, in about the same position as
that of the sei whale, which often becomes visible simultaneously with
the low, usually inconspicuous blow.
Minke whales are black to dark gray on the back and white on the belly
and on the underside of the flippers. Portions of the underside of the
flukes may be steel bluish gray. They have a diagonal band of white on
each flipper, the extent and orientation of which varies individually.
Like the fin whale, minke whales (at least from the Pacific) sometimes
have a chevron on the back behind the head and often have two regions of
lightish-gray coloration on each side--one just above and behind the
flippers; another just in front of and below the dorsal fin. These
patches may be quite conspicuous on some animals, indetectable on
others. These markings may also be present on Atlantic specimens, though
they have not yet been documented. The baleen, which may be visible from
close range when the animal is feeding, is mostly yellowish white with
fine white bristles. The posterior plates (up to half) may be brown to
black.
Natural History Notes
Minke whales are frequently found as single animals, pairs, or trios,
though they may congregate in areas of food concentration in the
northern seas during the spring and summer. They are more likely to be
seen up close than their larger cousins--the blue, fin, and sei
whales--because they often closely approach boats, particularly
stationary boats, as if curious about them.
Minke whales may also approach very close to shore and often enter bays,
inlets, and estuaries.
Like fin whales, they often arch the tail stock high into the air when
beginning a long dive. However, they do not raise the flukes above the
surface when beginning a dive.
Minke whales feed primarily on small shoal fish (herring, cod, pollack,
and capelin).
Minkes sometimes breach, leaping completely clear of the water and
entering smoothly, head first, or with a substantial splash like
humpback whales.
May Be Confused With
When they are seen at relatively close range, minke whales can be
readily distinguished from the other rorquals that have relatively tall,
falcate dorsal fins (fin, sei, and Bryde's whales) by their considerably
smaller size and by their distinctive white band on each flipper.
At a distance, however, positive identification may be difficult. Minke
whales have a small, low, inconspicuous blow. Like sei whales, they
frequently expose the dorsal fin simultaneously with the blow, but minke
whales hump the tail stock much higher when beginning a long dive--more
like fin whales.
From a distance, minke whales might also be mistaken for northern
bottlenosed whales (or any of several other beaked whales with a similar
dorsal fin). They can be distinguished by the differences in head shape,
body color and markings, and behavior, detailed on p. 67.
Distribution
Minke whales are distributed in the polar, temperate, and tropical
waters of the western North Atlantic. They are found from the pack ice
south to at least Anguilla, Lesser Antilles, and the eastern Gulf of
Mexico, though they appear to be most abundant in temperate waters north
of the latitude of New York and are infrequently reported from tropical
waters. At least some of the population migrates to the northern
portions of their range in spring and back south in autumn. They often
approach close to shore and enter river mouths, inlets, and estuaries.
Minke whales arrive along the Canadian coast in May or June. Some
migrate as far north as Hudson Strait, where they remain until the
freeze in October, November, or December. By December the majority of
the population has begun to move to the south, although some animals
remain behind so long as to become entrapped in the ice and die. Spring
and summer concentrations along the Canadian coast correspond to
concentrations of capelin, cod, and herring. Southern concentrations,
also corresponding with concentrations of herring, extend farther
offshore at least to the edges of the Grand Bank. Minke whales also
summer off the south coast of western Greenland, which they probably
reach from waters southwest of Iceland. Minke whales also occur in deep
pelagic waters.
Stranded Specimens
Stranded minke whales can be most readily identified by: 1) their small
size (to just over 30 feet [9.1 m]); 2) the transverse white bands on
the flippers; 3) the yellowish-white baleen plates (up to half the
posteriormost plates may be brown or black), 300-325 per side in number
and having fine white bristles (the plates are up to 4.75 inches [12 cm]
wide at the base and up to 8 inches [20.3 cm] long); and 4) by the 50-70
thin ventral grooves, ending well before the navel, often just even with
the flippers.
[Illustration: Figure 62.--The minke whale, at a maximum length of just
over 30 feet (9.1 m), the smallest baleen whale species of the western
North Atlantic, is distributed in polar, temperate, and tropical waters.
These animals usually have a low, inconspicuous blow and are sometimes
curious enough about boats that they will alter their course to
investigate them. Note the two areas of light gray on the sides of the
body, characteristic of at least Pacific minke whales. (_Photo from off
British Columbia, courtesy of_ Nanaimo Free Press.)]
[Illustration: Figure 63.--Three views of minke whales at sea. In all
note the transverse band of white on the flippers and the sharply
pointed head. Note the gray chevron visible on the back (top), the
absence of a conspicuous blow and the appearance of the prominent dorsal
fin on the surface while the blowholes are still exposed (middle), and
the distinctive regions of light gray on the sides (bottom). (_Photos
from off San Diego, Calif. by G. E. Lingle (top); from the northern West
Indies by H. E. Winn (middle); and from the western Pacific by Japanese
Whales Research Institute, courtesy of H. Omura (bottom)._)]
[Illustration: Figure 64.--Minke whales are also known as sharp-headed
finners. On this animal from the North Pacific, note the sharply pointed
head and the single central head ridge. (_Photo by Japanese Whales
Research Institute, courtesy of H. Omura._)]
[Illustration: Figure 65.--A minke whale stranded at Santa Barbara,
Calif. Note the dark back, the white-banded flipper, and the 60-70 fine
ventral grooves extending to just behind the flippers. The short, white
baleen plates are visible in the open mouth. (_Photo by S. Anderson._)]
[Illustration: Figure 66.--Minke whales have from 300 to 325 short,
yellowish-white baleen plates (up to half the anteriormost plates may be
brown or black) with fine white bristles on each upper jaw. (_Photo from
Santa Barbara, Calif. by S. Anderson._)]
NORTHERN BOTTLENOSED WHALE (T)
_Hyperoodon ampullatus_ (Forster 1770)
Other Common Names
None known.
Description
Northern bottlenosed whales reach a length of 32 feet (9.8 m) and are
robust in form. They are characterized by a bulbous forehead, which is
more pronounced on larger animals and most distinctive in adult males,
and by the dolphinlike beak displayed in animals of all sizes and ages,
which is sometimes visible as the animals surface steeply to breathe.
The blowhole is located in an indented area behind the bulbous forehead,
and the blow emanating from it projects upward or slightly forward to a
height of up to 6 feet (1.8 m), is bushy and is visible from a
considerable distance under low wind conditions. The dorsal fin, located
two-thirds of the way back on the back, reaches at least 12 inches (30.5
cm) in height and is distinctly falcate. The dorsal fin may be visible
from a distance of several hundred meters.
Northern bottlenosed whales are usually brownish in color, though the
markings change with age. Smaller animals are a uniform chocolate brown.
Larger animals retain the chocolate brown color on the back but are
often lighter on the sides and the belly and often have irregular
patches or blotches of grayish-white coloration on the back and sides.
Extremely large animals, presumably older males, often have a white
head. The flippers and the undersides of the flukes are uniformly brown
in color.
Natural History Notes
Northern bottlenosed whales often form tightly packed groups of up to 10
or more animals. This species holds the anecdotal record for the longest
dives, having been reported by early whalers to remain submerged over 2
h. They are probably deep divers, feeding primarily on squid (though
they may take fishes as well), and they rarely go in water shallower
than 100 fathoms (183 m).
After a long dive, northern bottlenosed whales will sometimes remain on
the surface for 10 min or more, blowing at regular intervals before
making another dive. After the last blow of a series or when the animals
are startled by a boat, they may show the tail flukes as they begin to
dive. The flukes are not notched on the rear margin.
Northern bottlenosed whales have been observed to show curiosity about
boats, coming to them from a considerable distance. They have also been
observed to "lobtail," raising the tail flukes above the water and
slapping them against the surface, and to jump clear of the water.
In the late 19th century, after stocks of bowhead whales were severely
reduced by overwhaling, northern bottlenosed whales became a prime
target of arctic whalers. They were sought because in addition to whale
oil produced from the body blubber, the forehead of the species yielded
quantities of spermaceti like that obtained from sperm whales.
May Be Confused With
Northern bottlenosed whales have a northerly and deep-water
distribution. Within their range, they may be confused at a distance
with minke whales, with sperm whales, or perhaps with North Sea beaked
whales.
Minke whales (p. 63) have a falcate dorsal fin located in approximately
the same position as that of the northern bottlenosed whale. However,
minke whales have a flathead in front of their two blow holes and are
black to dark gray on the back.
Sperm whales (p. 57) have a squarish head that may somewhat resemble
that of an adult male northern bottlenosed whale. However, there are
numerous characteristics which will permit these species to be
distinguished even from a distance:
NORTHERN
BOTTLENOSED WHALE SPERM WHALE
BLOW
Low and bushy; projects Low and bushy, projects
upward from indentation on obliquely forward from left
top of head. side of head; usually less
than 8 feet (2.4 m).
COLORATION
Lighter brown; adults splotched Brownish gray; body appears
with grayish white; wrinkled.
body smooth.
FLUKES
Rarely notched; seldom raised Notched; raised on long dive.
on long dive.
HEAD
Tapering in younger animals; Squarish, long, all black;
bulbous in adults; beakless.
white in older animals; beaked.
A further aid to distinguishing northern bottlenosed and sperm whales at
sea is the fact that the sperm whales that are found in areas where
northern bottlenosed whales are encountered are usually older, larger
males from 40 to 60 feet (12.2 to 18.3 m) long. Northern bottlenosed
whales do not exceed 32 feet (9.8 m).
Northern bottlenosed whales may also be confused with the poorly known
North Sea beaked whale (p. 82). When they can be examined at close
range, however, northern bottlenosed whales should be distinguishable on
the basis of the distinctly bulbous forehead.
Distribution
In the western North Atlantic, northern bottlenosed whales are
restricted to Arctic and north temperate waters, where they most
commonly occur in offshore areas. They have been reported from Davis
Straits and the entrance to Hudson Strait, the Gully southeast of Sable
Island, and as far south as Narragansett Bay, R.I.
In the spring and summer they concentrate near the northern limits of
their range, occasionally visiting deep channels of the Gulf of St.
Lawrence and eastern Newfoundland in summer. During these seasons they
may extend to the edge of the pack ice.
In the fall and winter the bulk of the population migrates southward.
Many probably winter in the Labrador Sea while others move farther
southward and farther offshore.
Stranded Specimens
Like the beaked whales discussed on p. 70 through 83, the northern
bottlenosed whales have no notch in the tail flukes, have two throat
grooves forming a V-shape on the chin, and have only two teeth in the
lower jaw, with those teeth emerged from the gums only in adult males.
These teeth may have sometimes fallen out of older males, but the tooth
sockets should still be visible in the gums.
NOTE: Some specimens--both male and female--will be found to have a
series of vestigial teeth the size of toothpicks in the upper and/or
lower jaws. Similar vestigial teeth, 5-40 in number, sometimes occur in
goosebeaked whales (p. 70). Further when they are prepared for museum
collections, the lower jaws of adult northern bottlenosed whales may be
found to contain a second pair of teeth just behind the first.
Northern bottlenosed whales may be distinguished from the remainder of
the beaked whale family, however, by the extremely robust body, by the
bulbous forehead, which is more extensively developed in larger animals,
particularly males, and by the pronounced dolphinlike beak.