Whales - Species | False Killer Whale

False Killer Whale - Pseudorca crassidens

When seen by the human eye from a distance, the False Killer Whale may appear to be its close relative, the Killer Whale. However, up close the False Killer Whales are more slender and mostly black in appearance. A small patch on the chest area between the flippers varies in each individual, from grey to white. This species of whale has no beak, with the head sloping gradually from the tip of the snout to the blowhole. Its dorsal fin is small and narrow, placed slightly forward of the middle of the back and directed backward. It has large conical shaped teeth of 15 to 25 millimeter diameter, with the largest projecting approximately 30 millimeters above the gums.

Male False Killer Whales have an average of 5.3 metres in length, while females average 4.5 metres. Mature males weigh up to 2,200 kilograms with females weighing approximately 1,200 kilograms. Groups of these whales may number from two to several hundred with both sexes and all age groups present. Mature adult males are larger than the females and seeming to prefer warmer deep offshore waters and some semi-enclosed seas such as the Red and the Mediterranean Seas. They prey on a variety of animals, including fish such as cod, yellowtail tuna and squid.

These whales are highly acrobatic, sometimes leaving the water when surfacing to breathe. They are fast active swimmers that easily approach boats and are known to emit â€œwhistlingâ€ sounds which are audible to humans. At times they may make sudden stops and swift turns, breaching often and twisting to fall back into the water causing a huge splash. They gracefully leap from the water when they are excited.

The False Killer Whaleâ€™s reproductive habits are poorly known. Breeding probably occurs the year round and the gestation period lasts approximately 15 months. Newborn false killer whales are born in the water, measuring about 1.5 meters in length and weighing 80 kilograms. Lactation occurs for one and a half to two years. False Killer Whales have low reproductive rates with calving approximately every seven years. These whales are known to be gregarious and form strong social bonds between themselves.

These whales are widely distributed, although not really abundant anywhere specific. Most of the data available on this species have been the result of strandings. There are numerous records of these animals being found in cool temperate waters, however, wanderers have been recorded as far afield as Norway and Alaska. For reasons unknown to man, False Killer Whales often strand. There have been three recorded mass strandings, the best known occurring in 1970, where 150 â€“ 175 whales beached themselves and refused to return to the sea, despite even the efforts of many volunteers. All the whales subsequently died but the cause of these strandings have never been determined

The fisheries bycatch is a major threat to the False Killer Whale, especially in Hawaii. They have been recorded interacting with fisheries, however, these types of interactions can cause dorsal fin disfigurement or death, which could affect their reproduction and survival. They have also been recorded in stealing yellowfin tuna off lines from large commercial fisheries. Their intentional death may result from this, as fisherman may want to decrease their competition for fish.