KILLER WHALE (T) 



Orcinus orca (Linnaeus 1758) 



Other Common Names 



Blackfish (see also pilot whales, p. 91 and 94), sword fish 

 (Canada), grampus (see p. 96), whitefish (St. Vincent), 

 Espladon (Quebec). 



Description 



Killer whales are the largest member of the dolphin 

 family. Adult males reach a length of at least 30 feet (9.1 m) 

 and are robust in form. One specimen of 31 feet (9.5 m) was 

 recorded for the western North Pacific. Females are 

 considerably smaller and less stocky. Newborn are 

 approximately 7-8 feet (2.1-2.4 m) long. Killer whales have 

 large paddle-shaped flippers. 



The most distinctive field character of the species is the 

 dorsal fin. In adult males it is extremely erect and may be as 

 much as 6 feet (1.8 m) tall. Though the fin of females and 

 immature males is less than 3 feet (0.9 m) tall, it is 

 nonetheless taller even in these animals than in any other 

 cetacean species and is distinctly falcate and pointed on the 

 lip. 



Killer whales are basically black with an extensive region 

 of white on the undersides extending from the lower jaw to 

 the anal region with a branch extending onto the flanks 

 behind the dorsal fin. There is an oval white patch on the side 

 of the head just above and behind the eye. In newborn and 

 very young calves, these regions may be tan to lemon yellow 

 in color. Most animals have a light-gray saddle marking just 

 behind the dorsal fin. The undersides of the flukes are 

 usually white. Both all-black and all-white animals have 

 been reported. 



Natural History Notes 



Killer whales travel in groups of from a few to 25 or 30 

 individuals, though herds of 150 have been reported. Males 

 appear polygamous, and females and young may form groups 

 separate from young bachelors and bulls. 



Killer whales are extremely fast swimmers, capable of 

 reaching top 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 



Chunky. 



BODY SHAPE 



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 char- 

 acteristic 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 



84 



