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