Body color black to dark gray.
Back frequently scarred.
Dorsal fin position varies with species.
Distribution varies with species.
Flukes not usually distinctly notched.
[Sidenote: KILLER WHALE
_Orcinus orca_
p. 84]
Body to at least 30 feet (9.1 m) long.
Body black with sharply demarcated white belly and oval white
patch above and behind eye; gray saddle behind dorsal fin.
Body chunky.
Dorsal fin in males can be very tall, sometimes 6 feet (1.8 m).
Dorsal fin in females and immature animals up to 3 feet (0.9 m),
distinctly falcate.
Distributed from tropics to Arctic; most common in colder waters.
Often seen in shallow bays and rivers and near shore.
Flukes may be raised on dive.
[Sidenote: FALSE KILLER WHALE
_Pseudorca crassidens_
p. 88]
Body to at least 18 feet (5.5 m) long.
Body black (faint gray blaze on belly between flippers).
Body slender.
Head small, tapering.
Large prominent teeth frequently visible at sea.
Flippers have distinct hump on leading edge.
Dorsal fin to 14 inches (35.6 cm), falcate, and from rounded to
pointed on tip.
Distribution pelagic tropical to warm temperate seas.
Frequently ride bow waves.
[Sidenote: ATLANTIC PILOT WHALE
_Globicephala melaena_
p. 91]
Body to at least 22 feet (6.7 m) long.
Body black with light gray, anchor-shaped area on chest; gray
saddle sometimes seen behind dorsal fin.
Head becoming more bulbous with age, somewhat squarish in adult
males viewed from above.
Tail humped.
Flippers long (to one-fifth of body length), sickle-shaped.
Dorsal fin broad-based, falcate to flaglike, in front half of
back.
Distribution primarily north temperate--about Hatteras north.
Flukes not usually raised on dive.
[Sidenote: SHORT-FINNED PILOT WHALE
_Globicephala macrorhynchus_
p. 94]
Body to at least 17.5 feet (5.3 m) long.
Body black with indistinct light gray area on chest; saddle
behind dorsal fin.
Head becoming more bulbous with age; square in large adult males
viewed from above.
Flippers relatively short (to less than one-sixth of body
length).
Dorsal fin broad-based, falcate to flaglike, in front half of
back.
Distribution tropical and warm temperate; from about Hatteras
south.
Flukes not usually raised on dive.
[Sidenote: GRAMPUS
_Grampus griseus_
p. 96]
Body to at least 13 feet (4.0 m) long.
Body of newborn light gray; darkens with age.
Body of adults light gray or white; scarred with numerous
scratches.
Head blunted, not beaked.
Forehead has vertical crease in center.
Dorsal fin less than 15 inches (38.1 cm), rather erect and
distinct, and dark even in light adults.
Distribution tropical to temperate.
Rarely ride bow wave.
(13-16 feet [4-5 m] maximum overall length)
Without a Dorsal Fin
The only two species of medium-sized cetaceans in the western North
Atlantic which have no dorsal fin, the Beluga or white whale and the
Narwhal, share such limited common range, well outside the theater of
normal boating traffic, that they are generally infrequently
encountered.
Both species are easily identifiable when seen.
[Sidenote: BELUGA
_Delphinapterus leucas_
p. 99]
Body to 16 feet (4.9 m) long.
Body of adults all white; young slate gray.
Small row of bumps along back ridge near midpoint, sometimes dark
brown.
Distribution usually near coast from Arctic waters to St.
Lawrence Gulf and into Hudson Bay.
[Sidenote: NARWHAL
_Monodon monoceros_
p. 102]
Body to 16 feet (4.9 m) long.
Body of adult brownish with grayish spots; body of young dark
bluish gray fading to white belly.
Head small; adults may have tusks up to 9 feet long (2.7 m).
Small row of bumps along back ridge.
Distribution usually in coastal waters from Arctic waters south
to Labrador coast.
SMALL WHALES, DOLPHINS, AND PORPOISES
(less than 13 feet [4 m] maximum overall length)
With a Dorsal Fin
The species in this group are not discussed in order of length; instead
the species of the genus _Stenella_ are treated together and then they
and other species are placed in near proximity to those animals with
which they are likely to be confused in the field.
[Sidenote: ATLANTIC SPOTTED DOLPHIN
_Stenella plagiodon_
p. 104]
Body to 7.5-8 feet (2.3-2.4 m) long.
Body dark purplish gray on back, lighter gray on sides and belly;
becomes increasingly spotted with increase in size.
Body has spinal blaze and light line from flipper to eye.
Beak white on tip.
Rides bow waves.
Distribution usually in tropical and warm temperate waters; most
common inside 100-fathom curve of continents.
[Sidenote: BRIDLED DOLPHIN
_Stenella frontalis_
p. 108]
Body to at least 7 feet (2.1 m) long.
Body dark gray on back; lighter gray on sides and belly.
Body has no spinal blaze.
Cape on top of head distinct.
Bridle: dark lines from eye to rostrum and from flippers to
corner of mouth.
Rides bow waves.
Distribution in tropical waters, primarily in West Indies.
[Sidenote: SPINNER DOLPHIN
_Stenella longirostris_
p. 110]
Body to at least 7 feet (2.1 m) long.
Body dark gray on back; tan on sides; white on belly.
Beak often long and slender, usually black above, white below.
Tip of snout and lips distinctly black.
Dorsal fin moderately falcate to triangular and very erect.
Rides bow waves.
Often jumps and spins on longitudinal axis.
Distribution in oceanic and coastal tropical waters.
[Sidenote: STRIPED DOLPHIN
_Stenella coeruleoalba_ = _Stenella styx_
p. 113]
Body to about 9 feet (2.7 m) long.
Body dark gray or bluish gray on back; gray on sides; gray or
white on belly.
Distinctive black stripes from: 1) eye to anus, 2) eye to
flipper.
Distinctive black blaze from behind dorsal fin to side above
flipper.
Rides bow waves.
Distribution temperate, subtropical, and tropical; seldom close
to shore.
[Sidenote: SADDLEBACK DOLPHIN
_Delphinus delphis_
p. 116]
Body to 8.5 feet (2.6 m); usually less than 7.5 feet (2.3 m)
long.
Body brownish gray to black; belly and chest white; crisscross
(hourglass) pattern of yellow tan on sides.
Distinct black stripe from center of lower jaw to flipper.
Rides bow waves.
Distribution temperate and tropical; seldom close to shore.
[Sidenote: FRASER'S DOLPHIN
_Lagenoldelphis hosei_
p. 120]
Body to at least 8 feet (2.4 m) long.
Body very robust in front of dorsal fin, resembling cross between
saddleback dolphin and Atlantic white-sided dolphin.
Beak very short and indistinct.
Distinct black stripe from beak to area of anus.
Dorsal fin and flippers small.
Distribution tropical (not yet recorded in western North
Atlantic).
[Sidenote: ATLANTIC WHITE-SIDED DOLPHIN
_Lagenorhynchus acutus_
p. 123]
Body to about 9 feet (2.7 m) long.
Dorsal fin part gray, part black; tall and distinctly falcate.
Distinctive patch of white on side; tan or yellow coloration
below and behind dorsal fin, often visible on swimming animal.
Beak short; all dark.
Does not usually ride bow waves.
Distribution Cape Cod to southern Greenland.
[Sidenote: WHITE-BEAKED DOLPHIN
_Lagenorhynchus albirostris_
p. 126]
Body to about 10 feet (3.1 m) long.
Dorsal fin all black, tall, and distinctly falcate.
Two pale areas: one in front, another behind and below dorsal
fin; visible on swimming animal.
Beak short, sometimes brushed with white blaze.
May ride bow waves.
Distribution Newfoundland north in summer, Cape Cod north in
winter; common close to shore at Cape Cod in spring.
[Sidenote: ATLANTIC BOTTLENOSED DOLPHIN
_Tursiops truncatus_
p. 128]
Body to 12 feet (3.7 m) long.
Body dark gray on back; lighter gray on sides; belly white to
pink.
Snout robust and short.
Dorsal fin tall; back curved.
Ride bow waves; often turn head downwards or to the sides as they
do so.
Distribution temperate and tropical, usually within 20 miles of
shore (often in bays, lagoons, and larger rivers) but extending
off the continental shelves.
[Sidenote: GUIANA DOLPHIN
_Sotalia guianensis_
p. 132]
Body to approximately 5.6 feet (1.7 m) long.
Body steel blue to dark brown on back; white on belly.
Dorsal fin nearly triangular; curves only slightly backward.
Distribution in Lake Maracaibo and the rivers of Guiana and in
the nearshore coastal waters of northeastern portion of South
America.
[Sidenote: ROUGH-TOOTHED DOLPHIN
_Steno bredanensis_
p. 135]
Body to about 8 feet (2.4 m) long.
Body dark gray to purplish gray on back with white or pink
blotches on sides; belly white.
Body frequently shows numerous white scars.
Head tapers gradually; beak long and slender; no clear separation
of beak from forehead.
May ride bow waves.
Distribution in deep tropical waters.
[Sidenote: PYGMY KILLER WHALE
_Feresa attenuata_
p. 138]
Body to 8-9 feet (2.4-2.7 m) long.
Body black with white belly patch which may extend up sides in
area of anus.
Head rounded; no beak; lips white; lower jaw and chin may be
white.
Dorsal fin to 15 inches (38 cm) tall, falcate; located near
midpoint of back.
Distribution tropical and subtropical.
[Sidenote: MANY-TOOTHED BLACKFISH
_Peponocephala electra_
p. 142]
Body to about 9 feet (2.7 m) long.
Body black on back; light gray on belly.
Head rounded; no beak; underslung jaw; lips white.
Dorsal fin to 10 inches (25.4 cm), tall, distinctly back curved.
Distribution tropical (not yet reported in western North
Atlantic).
[Sidenote: PYGMY SPERM WHALE
_Kogia breviceps_
p. 144]
Body to about 11 feet (3.4 m) long.
Body dark steel gray on back; lighter gray on sides; pinkish to
white on belly (older animals speckled on belly).
Head blunt; jaw underslung; false gills or bracket marks on side
of head.
Dorsal fin small; located in last one-third of body.
Has not been reported to ride bow waves.
Distribution in tropical and temperate waters.
[Sidenote: DWARF SPERM WHALE
_Kogia simus_
p. 148]
Body to about 9 feet (2.7 m) long.
Body dark steel gray on back; lighter gray on sides; pinkish to
white on belly.
Head blunt; jaw underslung; false gills or bracket marks on side
of head.
Body has two small creases on throat.
Dorsal fin like that of Atlantic bottlenosed dolphin; located
near midpoint of back.
Has not been reported to ride bow waves.
Distribution poorly known; at least from Georgia to the tropical
seas.
[Sidenote: HARBOR PORPOISE
_Phocoena phocoena_
p. 150]
Body to 5 feet (1.5 m) long.
Body dark brown above and white below; transition zone on sides
often speckled or streaked; ventral white extends high onto
side in front of dorsal fin.
Head rounded; beak small and indistinct.
Dorsal fin short and triangular.
Distribution in shallow waters from at least Delaware north;
generally found inshore; often in bays, river mouths and
inlets.
Does not approach boats.
SPECIES ACCOUNTS
Large Whales With a Dorsal Fin
BLUE WHALE (B)[9]
_Balaenoptera musculus_ (Linnaeus 1758)
[Footnote 9: The letter in parentheses indicates whether the species is
a baleen (B) or a toothed (T) whale.]
Other Common Names
Sulphur-bottom.
Description
Blue whales are the largest living mammals. Though reports of maximum
length and weight vary from one account to another, Antarctic blue
whales are known to have reached lengths to 100 feet (30.5 m) and
weights of over 150 tons (136,363 kg)[10] before stocks were severely
depleted by whaling operations. North Atlantic blue whales may be
expected to reach lengths of 80-85 feet (24.4-25.9 m). In all known
populations of blue whales, females are slightly larger than males of
the same age.
[Footnote 10: The largest measured specimen was "just over" 100 feet
(30.5 m); the largest specimen weighed, the 150-ton individual noted
above, was 89 feet (27.1 m) long.]
Viewed from above, the blue whale's rostrum is broad, flat, and nearly
U-shaped (actually shaped like a Gothic arch, slightly flattened on the
tip), with a single ridge extending from the raised area just in front
of the blowholes towards but not quite reaching the tip of the snout.
The dorsal fin is extremely small [to only 13 inches (33 cm)] and
variable in shape from nearly triangular to moderately falcate. In all
cases, it is located so far back on the animal's tail stock that it is
seldom visible until the animal is about to begin a dive.
Blue whales are light bluish gray overall, mottled with gray or grayish
white. Some animals may have yellowish or mustard coloration, primarily
on the belly, the result of the accumulation of diatoms during long
stays in the cooler waters to the north. The undersides of the flippers
are light grayish blue to white.
The baleen plates are all black.
Natural History Notes
The blow or "spout" is tall, to perhaps 30 feet (9.1 m), slender,
vertical, and not bushy, as is the blow of humpback whales, for
instance.
Although the blowing and diving patterns of blue whales may vary,
depending on the speed of movement and the activity of the whale when it
is encountered, they may be generally described as follows: If the
animal is moving slowly, the blowhole and part of the head may still be
visible when the dorsal fin breaks the surface, and the animal may
settle quietly into the water without exposing the last portion of the
tail stock or the tail flukes. If the animal is moving more quickly,
however, or is about to begin a long dive, the blowhole disappears below
the surface, a broad expanse of the back is exposed and disappears, and
the dorsal fin emerges briefly just before the animal lifts its tail
stock and flukes slightly above the surface before slipping out of
sight.
In this species it can be generally stated that the maximum height of
back in the area of the dorsal fin which is exposed above the surface as
the animal sounds is approximately four times the height of the dorsal
fin itself. The exposure of the tail flukes is unlike that of the
humpback whale (Fig. 39), the right whale (Fig. 50), or the sperm whale
(Fig. 57) in that when beginning a long dive all these other species
raise the flukes high out of the water and usually descend at a steep
angle. Blue whales lift the flukes only slightly, if at all.
Blue whales are relatively shallow feeders, feeding as they do almost
exclusively on "krill" (small shrimplike crustaceans), most of which are
distributed in the surface 330 feet (100 m). Blue whales usually occur
singly or in pairs.
May Be Confused With
At sea, blue whales may be confused with fin whales (p. 26) and though
the two are sometimes difficult to distinguish from a distance, the
following key differences permit identification at close range:
BLUE WHALE FIN WHALE
COLORATION
Mottled bluish gray above Gray above, white below; frequently
and below. grayish-white chevron
behind head, right lower
lip white.
BALEEN
All black. Bluish gray with yellowish-white
strips; front fifth to
third of baleen on right side
all white.
HEAD
Broad and nearly U-shaped; Narrower, more V-shaped;
all dark. right lower lip white.
DORSAL FIN
To 13 inches (33 cm); triangular To 24 inches (61 cm); falcate;
to moderately falcate; in located slightly more than a
last third of back; visible well third forward from tail
after blow. flukes; usually visible shortly
after blow.
SURFACING AND PREPARING TO DIVE
Often shows head and blowholes; Usually rolls higher out of
broad expanse of back water, particularly on long
and much later, dorsal fin. dive; dorsal fin visible shortly
after blow.
DIVING
Dives for 10-20 min; surfaces Dives 5-15 min (most often
and blows 8-15 times, making 6-7); surfaces steeply for 3-7
a series of 12- to 15-s dives blows then dives rather
between blows, then disappears steeply again; does not show
again; sometimes raises flukes on dive: on sounding,
flukes slightly on last dive; the maximum height of back
on sounding, the maximum in the area of dorsal fin which
height of back in the area of is exposed is approximately 2
dorsal fin which is exposed is times the height of the dorsal
approximately 4 times the fin.
height of the dorsal fin.
GROUPING
Usually found singly or in Occasionally found singly or
pairs. in pairs, more often found in
pods of six or seven individuals;
many pods, consisting of
as many as 50 animals, may
be found in small area.
See also comparison of fin whale and sei whale (p. 26).
Distribution
Though blue whales have been reported from the pack ice to Cristobal
Harbor, Panama Canal Zone, their normal range in the western North
Atlantic is more limited. In spring and summer months (about April
through at least August) they can be expected in the northern portion of
their range, at least as far north as the Arctic Circle, feeding on the
krill abundant in those waters. A small portion of the population may
venture north, beyond the Circle. In fall and winter the population
moves south, presumably into temperate and perhaps to tropical waters.
Reliable records include animals from observations off Long Island and
Ocean City, Md.
Though southern limits of the species are poorly known, there are no
records from Florida or the West Indies and no verified records from the
Gulf of Mexico.
Summaries of blue whale distribution based on records when the species
was more numerous indicate that they were found during spring and summer
months in some abundance on the Nova Scotian Banks, the St. Lawrence
Gulf and estuary, the Strait of Belle Isle, Grand Bank, and in the
waters off the coasts of Iceland, southern Greenland, and the Davis
Straits and Baffin Bay. (Some individuals have entered the Hudson Strait
but not apparently Hudson Bay itself.)
Historically, a few animals apparently appeared off the coast of
southeastern Canada as early as February. It was speculated that from
there a portion of the population underwent a migration from the Strait
of Belle Isle north through the Davis Straits to the waters off western
Greenland. Some individuals entered the Gulf of St. Lawrence after the
ice was clear and remained behind until as late as November. In the fall
months, certainly by November, the northern portion of the population
had begun retreating to the south in front of the advancing ice. The
remainder apparently also underwent this migration as well, since blue
whales have historically been nearly absent from Canadian waters during
midwinter.
Many of the migrating individuals were assumed to continue south to
temperate and, less frequently, to tropical water where they calved. It
should be emphasized that though all of the southward and the subsequent
northward migrations were presumed to be along pelagic routes, details
were poorly documented.
Blue whales have been reported in both shallow inshore and deep oceanic
zones.
Despite considerable attention in the popular literature to the plight
of the blue whale populations and frequent statements that they are near
extinction, blue whale stocks in the western North Atlantic appear more
abundant than has been usually reported. While present stocks are far
short of previous population sizes, which may have exceeded 200,000
individuals worldwide, they should be sufficiently large for the
species to continue their increase, barring renewed exploitation.
Stranded Specimens
Stranded blue whales can be readily identified by 1) the large body size
(to 85 feet [25.9 m]); 2) the broad flat head; 3) the all-black baleen
plates (270-395 in number), which are usually barely more than twice as
long as they are wide; and 4) the 55-88 ventral grooves extending to the
navel or beyond (Table 2).
Depending on the state of decay and the position of the stranded
specimen, any of the body characteristics described for living animals
may also be used to positively identify the specimen.
[Illustration: Figure 9.--Closeup views of swimming blue whales off
British Columbia (top) and Baja California (bottom). In both photos note
the broad rounded appearance of the head and the single, prominent
central head ridge. In the animal on the top note also the black baleen
plates, barely visible at the front of the slightly open mouth. In the
animal on the bottom note the pattern of light grayish-white mottling
along the back and the raised areas around the blowholes. These features
clearly mark these animals as blue whales. (_Photos by R. M. Gilmore
(top) and K. C. Balcomb (bottom)._)]
[Illustration: Figure 10.--The dorsal fins of blue whales may vary from
distinctly triangular (top) to broadly rounded (middle and inset) to
smoothly falcate in appearance (bottom). Regardless of its shape,
however, the fin is always located well back on the tail and does not
become visible until long after the animal's blow. (_Photos by Japanese
Whales Research Institute, courtesy of H. Omura, mid-Pacific (top); S.
Leatherwood, southern California (middle and inset); and F. W. True,
northern North Atlantic, courtesy of U.S. National Museum (bottom)._)]
[Illustration: Figure 11.--A blue whale swimming leisurely at the
surface off San Clemente Island, Calif. Note that the blowholes, marked
by the raised areas on the top of the head, are still exposed after the
dorsal fin has become visible. Note also the very small size and the
shape of the dorsal fin and its position well back towards the tail.
(_Photo by S. Leatherwood._)]
[Illustration: Figure 12.--A sequence showing fast-swimming blue whales
off southern California. The animal rises rather steeply to the surface
(a), emits a tall, vertical blow (b, c), shows its broad bluish back,
mottled with grayish white, and its small dorsal fin (d, e), and then
dives out of sight (f). When swimming in this manner, blue whales
sometimes raise their tail flukes slightly above the surface before
beginning their long dives (g). (_Photos by J. F. Fish (a-f) and K. C.
Balcomb (g)._)]
[Illustration: Figure 13.--Two views of blue whales on the ramps of
whaling stations in Japan (top) and at Hermitage Bay, Newfoundland
(bottom). Note the broad rounded appearance of the head, the single
central head ridge, and the dark bluish-gray coloration, interrupted
only by mottlings of grayish white. In the animal on the bottom note the
all-black baleen plates, which are very broad relative to their length.
(_Photos by Japanese Whales Research Institute, courtesy of H. Omura
(top); and F. W. True, courtesy of U.S. National Museum (bottom)._)]
[Illustration: Figure 14.--Dead blue whales, harpooned and afloat off
the stern of a factory ship in the Antarctic (top), and on the deck of a
whaling station in western Canada (bottom). In both, note the numerous
ventral grooves (from 55 to 85 or more) extending to the region of the
navel and sometimes beyond, and the light coloration of the undersides
of the flippers. Even though grooves are often present above the
flippers, and occasionally even on the side of the head, counts of
ventral grooves are usually made between the flippers. (_Photos by
Japanese Whales Research Institute, courtesy of H. Omura (top); and G.
C. Pike, courtesy of I. MacAskie (bottom)._)]
FIN WHALE (B)
_Balaenoptera physalus_ (Linnaeus 1758)
Other Common Names
Finback whale, finner, razorback, common rorqual.
Description
Fin whales have been reported to reach 79 feet (24 m). Females are
slightly larger than males of the same age.
The back is distinctly ridged towards the tail, prompting the common
name "razorback" whale.
The rostrum is narrower and more V-shaped than that of the blue whale
and has the same sort of single distinctive head ridge. The top of the
head is flat, though slightly less than that of the blue whale.
The dorsal fin is up to 24 inches (61 cm) tall; angled less than 40 deg. on
the forward margin, located slightly more than one-third forward from
the tail, and appears on the surface shortly after the blow.