Pygmy Killer Whale
Order Cetacea : Family Delphinidae : Feresa attenuata Gray

Description. A small, blunt-nosed, toothed cetacean similar to the false killer whale (Pseudorca), but dorsal fin larger and teeth considerably smaller; body color black with white patches around mouth and on chest and abdomen; dorsal fin about 220 mm high, 375 mm long at base, and located near midpoint of back; teeth about 8 mm in diameter at alveolus, less than 30 mm in length, and with 9-13 in each toothrow; 68-71 vertebrae (50 in Pseudorca). Total length about 2.5 m.

Distribution in Texas. Deep tropical, subtropical, and warm temperate waters of the world. Known in Texas on the basis of three strandings and one sighting of 20-25 animals about 130 km off the South Texas coast in November, 1980.

Habits. One of the best accounts of this whale to date is that by Taylor Pryor, Karen Pryor, and Kenneth Norris that appeared in the "Journal of Mammalogy" in 1965. The following account is excerpted from their report.

On July 6, 1963, a school of about 50 pygmy killer whales of several sizes (lengths varying from 1 to 2.5 m or so) was sighted from a boat off the island of Hawaii in waters about 600 fathoms deep. The school was resting quietly at the surface in a roughly circular group. The whales were aware of the approach of the boat but they did not flee; instead, they circled and dived in the same general area. When the crew of the boat netted an adult animal, the others made no attempt to assist the struggling captive although they remained within 30 or so meters of it.

The captive animal was unusually aggressive, as compared with other cetaceans its size, when it was being handled. It snapped at its captors and emitted a "blatting or growling" noise by forcing air through its blowhole. When released in the training tank at Sea Life Park, it made almost no attempt to avoid an observer, but instead acted as if it expected the observer to move. The day after capture, the animal was once observed to swim quickly with its mouth open toward the arm and hand of a man who was reaching into the tank to check a water input. The man withdrew his arm when the whale was about 2 m away, whereupon the animal closed its mouth and swam past. Ten days after capture the animal was moved to a tank containing an adult and an immature pilot whale (Globicephala). The pygmy killer became much more active than usual and swam ceaselessly. It was attracted to the small pilot whale and frequently chased it. One morning the small blackfish was found dead. Autopsy revealed that it had been killed by a single powerful blow — possibly a lethal butt from the pygmy killer whale to the temporal region of the cranium. The animal also exhibited aggressive behavior toward spotted dolphins (Stenella).

While in captivity, the pygmy killer whale learned to feed readily on mackerel and it consumed as much as 5 kg of such food a day. It also accepted squid.

Nothing seems to be known regarding reproduction and development in this species.

Illustration credit: Pieter A. Folkens.