speeds of 25 knots or more, and have been reported "porpoising" and
breaching. Individuals and entire groups have also been reported
"spy-hopping," or "pitchpoling," behaviors which consist of hanging
vertically in the water with the head and much of the body (to just
behind the flippers) exposed above the surface.
Killer whales feed on squid, fishes, sea turtles, seabirds, and marine
mammals.
Controversy still continues over whether or not killer whales pose a
threat to man. Documented attacks of killer whales on boats are rare and
have usually been provoked (i.e., harpooning or attempts to capture).
Only two uncertain instances of attacks in the wild have been reported,
but all divers and mariners should be cautioned that this powerful
animal is perfectly capable of doing tremendous damage and should not be
provoked.
May Be Confused With
Because of its very distinctive dorsal fin, body shape, and coloration,
the killer whale is not likely to be confused with any other whale when
it can be examined at close range or when an adult male is present in
the group. Pods of females and immature animals, however, may be
confused with false killer whales or with grampus. The killer whales may
be distinguished from false killers by the following differences:
KILLER WHALE FALSE KILLER WHALE
BODY SHAPE
Chunky. Slender.
BODY COLOR
Black with white on belly, All black with some gray on
flank, and head. belly.
DORSAL FIN
Very tall and erect in adult Shorter, slender, strongly
males; tall and slightly back falcate.
curved in female.
HEAD SHAPE
Broad, rounded. Tapered, slender.
FLIPPER SHAPE
Paddle-shaped. Moderately long with
characteristic hump near
middle on forward margin.
LENGTH
To at least 30 feet (9.1 m). To at least 18 feet (5.5 m).
Furthermore, false killer whales are the only "blackfish" which are
known to ride the bow wave of a ship.
Grampus have a tall dorsal fin (15 inches [38.1 cm]) which is very
similar in appearance to that of adult female and juvenile killer
whales. But grampus have much lighter coloration, from slate gray to
nearly all white, and larger animals are covered with numerous
scratches. Upon closer examination they can be further distinguished
from killer whales by a crease in the front of the head dividing the
melon into two distinct sections. Grampus are considerably smaller, to
about 13 feet (4 m) maximum length.
Distribution
In the western North Atlantic killer whales have been reported from the
polar pack ice south to Florida and St. Vincent, Lesser Antilles, and
into the Gulf of Mexico at least as far as Texas, though they are far
more common in the cooler waters from about New Jersey north.
Throughout their range, killer whales seem to prefer coastal areas and
often enter shallow bays, estuaries, and river mouths in search of food.
Migrations of the species are probably closely tied to movements of
their food supply. They annually arrive on the coast of New England with
the tuna. Along the Canadian coasts, where distribution and migrations
have been described in some detail, killer whales appear to move inshore
in spring and summer. Many arrive off the east coast of Newfoundland in
June, the Strait of Belle Isle in June and July, and slightly later
along the Labrador coast and Arctic waters. They are found around the
loose ice in April, presumably feeding on harp seals, _Pagophilus
groenlandicus_, and hooded seals, _Cystophora cristata_, and are
frequent in the St. Lawrence estuary in spring and autumn following the
movements of the white whales. The northward movements in spring also
coincide with migrations of balaenopterine whales, which have also been
reported among the food items. Killer whales may remain in arctic or
subarctic waters until driven out by new forming ice in October and
November. Though the migration has not been as thoroughly described,
killer whales apparently begin shifting southwards in autumn.
Stranded Specimens
Stranded killer whales should be readily identifiable by the robust
body, the distinctive body markings, and in larger animals the tall
dorsal fin. Killer whales have from 10 to 12 large, prominent teeth on
each side of the upper and lower jaws.
[Illustration: Figure 89.--Killer whales are often distributed very
close to shore. In these photos from Baja California, they are shown in
two characteristic behaviors--breaching (top) and "spy-hopping" or
"pitchpoling" (bottom). (_Photos by S. Leatherwood._)]
[Illustration: Figure 88.--A small herd of killer whales off southern
California (top) and details of an adult male from that herd (middle)
and of females or immature males off Islas San Benito, Baja California
(bottom). Adult males have a tall erect dorsal fin, which may be more
than 6 feet (1.8 m) tall, while the fins of females and immature males
are less than 3 feet (0.9 m) tall, distinctly falcate, and pointed on
the tip. Both sexes frequently have a grayish-white region, called a
"saddle," behind the dorsal fin. (_Photos by T. Dohl (top and middle)
and S. Leatherwood (bottom)._)]
[Illustration: Figure 90.--A leaping killer whale in California
aquarium. Note the distinctive coloration of the species, white on the
lower jaw, the belly and the anus, and on both sides above the anus.
Note also the distinctive white eye patch often visible on animals at
sea. (_Photo by D. K. Caldwell._)]
[Illustration: Figure 91.--Killer whales have from 10 to 12 large
prominent teeth, curved slightly backwards and inwards on each side of
each jaw. (_Photos from Point Mugu, Calif. by S. Leatherwood._)]
FALSE KILLER WHALE (T)
_Pseudorca crassidens_ (Owen 1846)
Other Common Names
Mongoose (St. Vincent).
Description
False killer whales in the western North Atlantic reach a length of at
least 18 feet (5.5 m). Males are slightly larger than females. Calves
from 5 to 7 feet (1.5 to 2.1 m) may be seen at any time throughout the
year.
The dorsal fin, located just behind the midpoint of the back, is from 7
to 16 inches (17.8 to 40.6 cm) tall, falcate, and variable to sharply
pointed on the tip. The flippers are characterized by a broad hump on
the front margin near the middle, a characteristic which is diagnostic
for the species.
The body of the species is all black except for a blaze of gray on the
belly between the flippers. This blaze varies from barely visible to
light grayish white similar to but generally fainter than that of pilot
whales. The body is long and slender, and the head is narrow and gently
tapered from the area of the blowhole forward.
Natural History Notes
False killer whales are a social form and may occur in herds of up to at
least 100 individuals. They often jump clear of the water and frequently
ride the bow waves of vessels. They are the only "blackfish" which are
known to do so. False killer whales feed primarily on squid and large
fishes and are notorious for their habit of stealing fish from the lines
of fishermen. The large prominent teeth may be visible on a swimming
animal.
May Be Confused With
False killer whales may be confused with killer whales, pilot whales, or
the smaller, poorly known pygmy killer whale (p. 138) and many-toothed
blackfish (p. 142).
The characteristics distinguishing the species from the killer whale are
tabularized on p. 84; its differences from the pilot whales are
summarized on p. 92.
At sea, false killer whales are distinguishable from the other two
species primarily by their larger size and differences in coloration.
False killer whales are up to 18 feet (5.5 m) in length. Pygmy killer
whales and many-toothed blackfish reach only 8-9 feet (2.4-2.7 m) in
length. Pygmy killer whales have an extensive region of white on the
belly which may extend onto the sides and both pygmy killer whales and
many-toothed blackfish have a distinctive white region on the lips,
usually lacking or indistinct on false killer whales.
Neither of the smaller species of blackfish has been reported to ride
bow waves.
Distribution
False killer whales are widely distributed in the pelagic tropical,
subtropical, and warm temperate waters of the western North Atlantic.
They have been reported from off Maryland south along the mainland
coasts of North America, in the Gulf of Mexico from Cuba and the Lesser
Antilles, and from the southeast Caribbean Sea. The species has been
reported from Venezuela.
Stranded Specimens
Stranded false killer whales can be positively identified by: 1) the
large size (to 18 feet [5.5 m]); 2) the slender body tapering rapidly to
a long slender head; 3) the markedly long mouth, with from 8 to 11
large, conspicuous teeth in each side of each jaw recalling those of the
killer whale, but circular and not, as in killer whales, elliptical; 4)
the unusually shaped flipper bulging conspicuously on the forward
margin.
For comparison with "blackfish" of similar size (the pilot whales) see
p. 92 and 94.
False killer whales do not appear to occur frequently in coastal waters,
sandy bays, or estuaries, though entire herds have stranded in such
areas. Records from throughout the range suggest that the species has an
oceanic distribution.
[Illustration: Figure 92.--False killer whales at sea 600 miles (968.0
km) off northeastern Florida. Note the smoothly falcate dorsal fin,
pointed on the tip, and located near the midpoint of the back. Dorsal
fins of this species may also be rounded on the tip but all are sharply
concaved on the rear margin. (_Photo by H. E. Winn._)]
[Illustration: Figure 93.--False killer whales are the only "blackfish"
that routinely ride the bow waves of vessels. On this animal riding on
the bow wave of a research ship, note the all-black coloration of the
back, head, and sides and the broad "hump" near the middle of the
flippers on the leading edge. (_Photo 600 miles [968 km] off
northeastern Florida by H. E. Winn._)]
[Illustration: Figure 94.--A false killer whale stranded in northeastern
Florida. Note the narrow tapering head, overhanging the lower jaw by
several inches, the position and shape of the dorsal fin and the
distinctive "hump" on the leading margin of the flippers. (_Photo by W.
A. Huck, courtesy of Marineland of Florida._)]
[Illustration: Figure 95.--Entire herds of false killer whales sometimes
strand themselves. In this dorsal view of an animal stranded in
southeastern Florida, note the extremely distinctive "hump" on the
forward margin of the flippers and the narrow head, tapering towards the
tip of the snout. (_Photo by J. Krol._)]
[Illustration: Figure 96.--False killer whales have from 8 to 11 large,
conspicuous teeth in each side of each jaw. These teeth are often
visible in swimming animals, particularly when they are engaged in their
obnoxious habit of stealing fish from the lines of fishermen. The teeth
are so distinctive that they can also be used to identify even a badly
decomposed stranded specimen. (_Photo, courtesy of Sea Life Park,
Hawaii._)]
ATLANTIC PILOT WHALE (T)
_Globicephala melaena_ (Traill 1809)
Other Common Names
Northern pilot whale, long-finned pilot whale, pothead, blackfish,
calling whale, caa'ing whale.
Description
Male Atlantic pilot whales reach an average length of at least 20 feet
(6.2 m). Females are slightly smaller, probably not exceeding 18 feet
(5.5 m). Young are 5-7 feet (1.5-2.1 m) at birth.
The head is thick and bulbous, a characteristic which reaches an extreme
in the development of the head of adult males (prompting the common name
"pothead"). The flippers are long (to one-fifth of the body length, or
more) and sickle-shaped. The tail is dorsally thickened just in front of
the flukes.
The dorsal fin of this species is one of its most distinctive
characteristics. It is low in profile, has a long base, is set far
forward on the animal's back, and is falcate to "flaglike" in
appearance. The dorsal fin of adult males reportedly has a thicker
leading edge and a rounder form than that of the female.
Atlantic pilot whales are black on the back and sides (prompting the
common name "blackfish") but have an anchor-shaped patch of grayish
white on the chin and a gray area on the belly, both of which are
variable in extent and intensity. Some larger animals have a gray saddle
behind the dorsal fin, though this zone of color is found more
frequently in short-finned pilot whales. Young animals are often a
lighter medium gray.
Natural History Notes
Atlantic pilot whales may occur in herds of 200 animals or more, though
herds of 50 or fewer (4-6) are more common. They are sometimes found in
association with Atlantic white-sided dolphins.
Pilot whales are sometimes found hanging vertically in the water with
the head and part of the back out of the water in what has been called
"spy-hopping" or "pitchpoling." Individuals frequently lobtail. Pilot
whales infrequently breach, a behavior which is usually confined to
younger animals. They do not ride bow waves.
Atlantic pilot whales feed primarily on squid but also take cod and
other fishes. A Pacific pilot whale, a closely related species, was
found by radio telemetric studies to be capable of diving to 2,000 feet
(609.6 m).
Atlantic pilot whales were formerly the object of an active shore
fishery off Newfoundland (1950-1971). In addition, entire herds and,
less frequently, individuals are sometimes stranded.
May Be Confused With
Atlantic pilot whales are most likely to be confused with false killer
whales, with which they share the waters from off Virginia to those off
Maryland. The two species may be distinguished by the following
characteristics:
ATLANTIC PILOT WHALE FALSE KILLER WHALE
SHAPE OF HEAD
Thick and often squarish in Slender, gently tapering
larger animals. mouth long.
SHAPE OF BODY
Robust. Long and slender.
DORSAL FIN
Broad-based and falcate. Slender, tall, falcate, and
pointed on tip.
COLORATION
Black with gray saddle Mostly black with gray blaze
sometimes evident behind of variable extent and
dorsal fin and gray region intensity on belly between
on chin and belly. flippers.
BEHAVIOR
Will not ride bow waves; May ride bow waves, often
seldom breaches. "porpoises" and breaches.
RANGE
Temperate waters from at Temperate seas from at least
least North Carolina north. Maryland south.
In the extreme southern portion of their range, Atlantic pilot whales
may be confused with short-finned pilot whales with which they have only
a limited seasonal common range. Characters distinguishing these species
are subtle and may not be adequate to permit them to be distinguished at
sea. For purposes of this guide it is generally that pilot whales living
north of lat. 38 deg.N (Virginia coast) are Atlantic pilot whales and those
living south of lat. 38 deg.N are short-finned pilot whales.
Distribution
Atlantic pilot whales, the northernmost of the two pilot whales species,
are found in winter from the Grand Banks south as far as North Carolina
and in summer from Iceland and Greenland south to the New Jersey coast.
Winter concentrations of pilot whales may be found off the Newfoundland
coast and near Cape Cod, Mass. Atlantic pilot whales are distributed
both in coastal waters and in deep waters off the continental shelf.
Stranded Specimens
As discussed above, individuals and groups of pilot whales frequently
strand themselves for still incompletely understood reasons. They may be
identified as pilot whales primarily by: 1) the robust body and bulbous
head, which is often squarish in adult animals, and 2) the broad-based,
falcate dorsal fin located far forward on the back. Accurate
determination of the pilot whale species involved in the stranding may
require museum preparation of the skull and detailed examination of its
characteristics. Preliminary identification may be made, however, based
on the following:
ATLANTIC PILOT WHALE SHORT-FINNED PILOT WHALE
FLIPPER LENGTH
To one-fifth body length, To one-sixth body length, or
or more. less.
NORMAL RANGE
From North Carolina north. From North Carolina south.
TEETH
8-11 per row. 7-9 per row.
[Illustration: Figure 97.--A herd of Atlantic pilot whales off
Massachusetts. The most distinguishing field characteristic of this
species, and of their southern cousins, the short-finned pilot whales,
is the highly distinctive dorsal fin, extremely long based, low in
profile, and set well forward on the animals' backs. (_Photo by W. A.
Watkins._)]
[Illustration: Figure 98.--Atlantic pilot whales frequently "lob tail"
(raise the tail flukes above the surface and slap them against the
water) (top) and pitchpole or spy-hop (hang vertically in the water with
the head up and the tail down) (bottom). (_Photos from the North
Atlantic by H. E. Winn._)]
[Illustration: Figure 99.--North Atlantic pilot whales on the deck of a
whaling station in Newfoundland. The anchor-shaped patch on the chin and
the gray color of the belly are apparently more vivid and extensive in
this species than in the short-finned pilot whales. Further, the flipper
is longer, measuring one-fifth of the body length, or more, in adult
animals. The flippers of short-finned pilot whales (see Fig. 102)
measure one-sixth of the body length or less. (_Photo by J. G. Mead._)]
SHORT-FINNED PILOT WHALE (T)
_Globicephala macrorhynchus_ Gray 1846
Other Common Names
Blackfish (see also p. 84, 91, and 94).
Description
Male short-finned pilot whales of the western North Atlantic reach
lengths of at least 17.5 feet (5.3 m). Females are reportedly slightly
smaller than males (recorded only to 15.5 feet [4.7 m]).
The head, somewhat like that of the Atlantic pilot whales (p. 91), is
thick and bulbous, a characteristic which reaches its extreme in the
development of a flattened or squarish appearance to the front of the
head in mature males (see Fig. 101). In very old males the melon may
overhang the mouth up to several inches. The flippers are shorter than
those of the other pilot whale species of the western North Atlantic
(thus the common name short-finned pilot whale), reaching only one-sixth
of the body length or less. The tail is dorsoventrally thickened just in
front of the flukes.
The dorsal fin, like that of the Atlantic pilot whale, is one of the
species' most distinctive characteristics. It is low in profile, has a
long base, and is set far forward on the animal's back.
Short-finned pilot whales are all black on the back sides and most of
the belly with an anchor-shaped patch of gray on the chin and a gray
area of varying extent and intensity on the belly. These areas are less
vivid and extensive than those on Atlantic pilot whales. Younger animals
are lighter, often medium gray.
Natural History Notes
Short-finned pilot whales are known to occur in groups of 60 animals or
more, though smaller groups are more common. They have been reported
pitchpoling (spy-hopping), lobtailing, and--rarely--breaching.
Short-finned pilot whales feed on squid and fish.
May Be Confused With
In the tropical portion of their range, short-finned pilot whales may be
confused with pygmy killer whales (p. 138) and many-toothed blackfish
(p. 142). They may be distinguished from both species primarily by their
distinctive dorsal fin and the bulbous-to-squarish head. Both pygmy
killer whales and many-toothed blackfish have dorsal fins, which are
more falcate, slender, and pointed on the tip, and have longer,
slenderer heads.
Throughout their range short-finned pilot whales may be confused with
false killer whales. The two species may be distinguished by the same
differences which distinguish Atlantic pilot whales from false killer
whales (p. 91).
In the extreme northern portion of their range, short-finned pilot
whales may be confused with Atlantic pilot whales. The two species may
be distinguished by differences itemized on p. 93.
Distribution
Though short-finned pilot whales are known from Delaware Bay, their
normal range appears to extend from Bermuda and Cape Hatteras (Virginia
in summer) south to the Venezuelan coast. They have been reported for
the Gulf of Mexico, the Caribbean, and the islands of the West Indies.
Stranded Specimens
Stranded short-finned pilot whales may be confused with any of the
species itemized under living animals. They may be identified as pilot
whales primarily by the robust body and bulbous head, often squarish in
adult animals, and the broad-based, falcate dorsal fin located well
forward on the animal's back. Accurate determination of the pilot whale
species involved may require museum preparation of the skull and
detailed examination of its characteristics. Preliminary identification
may be made, however, on the basis of the following:
ATLANTIC PILOT WHALE SHORT-FINNED PILOT WHALE
DISTRIBUTION
Primarily North Carolina Primarily North Carolina
north. south.
FLIPPERS
To one-fifth body length, To less than one-sixth body
or more. length.
TEETH
8-11 per row. 7-9 per row.
[Illustration: Figure 100.--Short-finned pilot whales stranded in
northeastern Florida, shown here swimming in the lagoon at Marineland of
Florida. This species, like their northern cousins, the Atlantic pilot
whales, have a highly distinctive dorsal fin and a bulbous head (see
Figs. 97, 99). In these photos note the variation in the shape of the
head. Those of females and immature males are more rounded. Those of
adult males are far more blunted. (_Photo courtesy of Marineland of
Florida._)]
[Illustration: Figure 101.--Short-finned pilot whales have from 7 to 10
teeth in each side of each jaw. The bulbous forehead of the species is
far less pronounced in females and immature males (left). The head of
mature males is extremely "squarish" and may overhang the lower jaw by
several inches (right). (_Photos from Aquatarium (left) and southeastern
Florida by D. K. Caldwell (right)._)]
[Illustration: Figure 102.--The flippers of short-finned pilot whales
reach only about one-sixth of the body length, while those of the
Atlantic pilot whale may be one-fifth the body length or more. Note the
length of the flippers of the pilot whale in the background, relative to
its overall length. (_Photo from South Carolina by J. G. Mead._)]
GRAMPUS (T)
_Grampus griseus_ (G. Cuvier 1812)
Other Common Names
Risso's dolphin, gray grampus, white-headed grampus, mottled grampus,
Risso's porpoise, hard knocks (St. Vincent), white blackfish (Cape Cod).
Description
Grampus reach a maximum length of about 13 feet (4 m). The body is
robust, particularly in front of the dorsal fin, and lacks a distinct
beak. The head is somewhat bulbous and is marked on the front by a
V-shaped crease with the point downwards, which divides the melon into
two parts. The flippers are long and pointed on the tips. The dorsal
fin, located at about the midpoint of the body, is tall, to 15 inches
(38.1 cm) or more, and distinctly falcate. The body narrows rapidly
behind the dorsal fin and the tail stock is quite narrow. The flukes are
broad, concaved on the rear margin, and deeply notched.
The bodies of grampus are a uniform light gray at birth. As the animals
age, their color darkens to almost black with distinctive regions of
grayish white on the belly and chest. The body of older adults is cream
white or silver gray, particularly on the head, with numerous scars,
presumably from encounters with other grampus and perhaps with the
squid, which are one of the species' major food items.
The flippers, dorsal fin, and tail flukes usually remain dark even in
adults.
Natural History Notes
Grampus are found in herds of up to several hundred individuals and may
be seen "porpoising" (leaping from the water) as they surface to
breathe, and breaching. They sometimes ride the bow waves of a boat.
Grampus feed on fish and squid.
May Be Confused With
From a distance grampus are most easily confused with Atlantic
bottlenosed dolphins. They may be most readily distinguished by the
following differences:
ATLANTIC BOTTLENOSED
GRAMPUS DOLPHIN
SIZE
To 13 feet (4 m). Rarely to 12 feet (3.7 m);
usually less than 10 feet
(3.1 m).
BODY COLOR
Young are uniform light Dark gray on body; lighter
gray; older animals dark gray on sides; white or pink
with grayish regions on on belly; may appear brownish
chest and belly; very in water.
old animals white and
scarred.
DORSAL FIN
To 15 inches (38.1 cm); To 12 inches (30.5 cm) less
sharply falcate; pointed sharply falcate; pointed on
on tip. tip.
HEAD COLOR AND SHAPE