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]).