False killer whale
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Pseudorca crassidens

Names

Azores : Negro - POR : Falsa-orca - ITA : Pseudorca - SPAIN : Orca falsa - GB : False killer whale - GER : Falchser NEDER : Swarte zwaardwalvis - JAP : Oki gondo kujira

Biology

Adults measure 5 to 6 m long and weigh to 2.2 tons. The females measure 4 to 5 m and weigh up to 1.2 tons. In each jaw, they have 8 to 11 pairs of teeth, circular in cross section. The body is all black, the reason for their common name " Negro " in the Azores, except for a blaze of gray on the ventral region between the pectorals. The body is long and slender presenting an underdeveloped melon. They do not have a beak. This animal, described usually as very aggressive by fishermen, has acquired a bad reputation but, in captivity, demonstrates a quite peaceful behaviour. Unfortunately it is true that these animals have the habit of attacking large fish, but they also feed on cephalopods. Newborns measure 1.5 to 2.1 m and weigh 80 kg. Gestation lasts 11 months and lactation takes 18 months. The total duration of the reproduction cycle is still unknown. They can live to 20 years old. They are very gregarious animals and communication has no doubt a very important role in group unity. The sounds they can emit are extremely diversified. In fact, it is possible that each animal produces its own different sound.

Observation

In the Azores, this large Delphinidae is frequently observed near other species. These other species do not seem to care about the bad reputation of the false killer whales. They seem to be perfectly content with their company, although they sometimes fight with them. Timid but very active, the false killer whale can be seen frequently riding bow waves, then maneuvering quickly (up to 15 knots) and jumping completely out of the water, provoking a splash that looks as if it was made by a larger species such as the sperm whale. The team at Espaço Talassa was able to observe these false killer whales on different occasions (in about 6 % of our field trips). They appeared usually as a large herd with tens and sometimes hundreds of individuals, usually 3 to 4 miles away from the coast. This species can be confused with the Globicephala macrorhynchus. However, the false killer whale is darker than the latter species, is a slightly faster swimmer, is more active, and can be distinguished mainly because its dorsal fin is taller. The false killer whale is larger than the pygmy sperm whale and its colour differentiates it well from the female killer whale. The blow is frequently visible, and the adults breathe every 15 to 20 s. This species emerges frequently with open mouth, showing their impressive teeth.

Cetaceans in the Azores