| Killer Whale | False Killer Whale |
|---|---|
| BODY SHAPE | |
| Chunky. | Slender. |
| BODY COLOR | |
| Black with white on belly,flank, and head. | All black with some gray onbelly. |
| DORSAL FIN | |
| Very tall and erect in adultmales; tall and slightly backcurved in female. | Shorter, slender, stronglyfalcate. |
| HEAD SHAPE | |
| Broad, rounded. | Tapered, slender. |
| FLIPPER SHAPE | |
| Paddle-shaped. | Moderately long withcharacteristic hump nearmiddle 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.
