This species was thought to be extinct until approximately 50 years ago, because only skulls and other bones washed ashore.
Pseudorca crassidens use echolocation primarily in the frequency range of 20 yo 60 kHz. They also use higher frequencies of 100 to 130 kHz. False killer whales, like other toothed whales also use other sounds, such as whistles, squeals, or less distinct pulsating sounds. It has been noted that whenever researchers get close to a group of false killer whales, they have been able to detect the whales' piercing whistles from about 200 meters away. James Porter notes, "The noises were astonishingly diverse, much more varied than the sounds of human speech, both in pitch and intensity. Each whale seemed to be making different sounds. The cacophony gave the impression that whatever they were 'saying', they were not all 'saying' the same thing at the same time (Watson 1981)."
Communication Channels: tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; ultrasound ; echolocation ; chemical
Although false killer whales are hunted by humans and there are annual mass strandings, populations are considered stable. There are only a few countries that hunt them for food or remove them as threats to the fisheries industry.
US Federal List: no special status
CITES: appendix ii
State of Michigan List: no special status
IUCN Red List of Threatened Species: data deficient
These whales will eat fish off of fishing lines and out of nets of commercial fishing operations.
In the eastern tropical Pacific, Pseudorca crassidens is taken for food and also to limit their consumption of tuna Osteoglossiformes and inhibit their competition with commercial fisheries.
Positive Impacts: food
False killer whales are predators of fish and squid (Uroteuthis duvauceli), and they also eat smaller delphinids and pinnipeds (e.g., seals [Phocidae], and sea lions [Otariidae]).
One protozoan that is found in false killer whales are the parasites Bolbosoma capitatum. They are also carriers of two types of whale lice: Lsocyamus delphini and Cyamus antarcticensis.
Commensal/Parasitic Species:
False killer whales are carnivores, eating primarily fish and squid. They mainly eat squid (Loligo) but also opportunistically take fish and occasional marine mammals, such as seals (Phocidae) or sea lions (Otariidae). Some of the fish they eat include salmon (Oncorhynchus), squid (Loligo, Berryteuthis magister, or Gonatopsis borealis), sciaenid and carangid fishes, bonito (Sarda lineolata), mahi mahi (Coryphaena hippurus), yellowfin tuna (Thunnus albacares), yellowtail (Pseudosciana manchurica), and perch (Lateolabrax japonicus). On one occasion researchers found the remains of a humpback whale Megaptera noveangliae in the stomach of a false killer whale.
This species moves quickly in order to catch fish. They have been observed catching a fish in their mouth while completely breaching the waters' surface. They have also been seen shaking their prey until the head and entrails are shaken off. They then peel the fish using their teeth and discard all the skin before eating the remains. Some mothers will hold a fish in the mouth and allow their calf to feed on the fish. This food manipulation is rare in cetaceans.
Animal Foods: mammals; fish; mollusks; other marine invertebrates
Primary Diet: carnivore (Piscivore , Molluscivore )
Pseudorca crassidens is found throughout the Atlantic, Pacific, and Indian Oceans. It is nearly cosmopolitan, occurring at latitudes as far north as 50 degrees north and as far south as 52 degrees south.
This species has been observed as far south as New Zealand, Peru, Argentina, South Africa, and the north Indian Ocean. They also range from Australia, the Indo-Malayan Archipelago, Philippines, and north to the Yellow Sea. They have been observed in the Sea of Japan, coastal British Columbia, coastal Maryland (USA), the Bay of Biscay, and have been discovered in the Red and Mediterranean Seas. Many pods live near the Gulf of Mexico and surrounding the Hawaiian Islands.
Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native ); mediterranean sea (Native )
Other Geographic Terms: cosmopolitan
False killer whales are common in tropical or temperate seas. They visit coastal waters but prefer to remain in deeper waters. They are known to dive as deep as 2000 meters.
Range depth: 0 to 2000 m.
Average depth: 500 m.
Habitat Regions: temperate ; tropical ; saltwater or marine
Aquatic Biomes: pelagic ; coastal
Researchers estimate that males live an average of 57.5 years and females live an average of 62.5 years in the wild. No known age-dependent mortality rate has been discovered. Because few false killer whales are kept in captivity, captive lifespans are unknown.
Average lifespan
Status: wild: 60 years.
Average lifespan
Status: wild: 22.0 years.
False killer whales are black or dark gray with a white blaze on their ventral side. Some have a paler gray coloring on their head and sides. Their heads are rounded and often described as blunt and conical with a melon-shaped forehead. Their bodies are elongated. The dorsal fin is sickle-shaped and protrudes from the middle of their back, the pectoral flippers are pointed. They have a slight overbite--the upper jaw extends beyond the lower jaw. This gives them a slight beaked look to their rostrum. No subspecies have been described.
Adult males range from 3.7 to 6.1 m in length, while adult females range from 3.5 to 5 m. Adults may weigh 917 to 1842 kg. Newborns range from 1.5 to 1.9 m in length and weigh about 80 kg. The dorsal fin can grow to be 18 to 40 cm high. This species has a more slender build compared to other dolphins and they have tapering heads and flippers. Their flippers average about one-tenth of the head and body length and have a distinct hump on the leading margin of the fin. There is a definite median notch on their flukes and they are very thin with pointed tips. False killer whales also have 8 to 11 teeth on each side of their jaw.
The skulls of females range in length from 55 to 59 cm, while males are 58 to 65 cm. They have 47 to 52 vertebrae: 7 cervical, 10 thoracic, 11 lumbar, and 20 to 23 caudal vertebrae. They have 10 pairs of ribs. Their manus consists of 6 carpals, 5 metacarpals, and 14 phalanges.
This species is often mistaken for bottlenose dolphins (Tursiops truncatus), short-finned pilot whales (Globicephala macrorhynchus), or long-finned pilot whales (Globicephala melas) as they inhabit the same regions. To distinguish these species, bottlenose dolphins have beaks, and pilot whales are larger with obvious dorsal fin differences.
Range mass: 916.26 to 1841.59 kg.
Range length: 3.5 to 6.1 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger; sexes shaped differently
Due to their harmful effects on fisheries, humans kill false killer whales. In some regions in the eastern tropical Pacific, they are hunted for meat.
Known Predators:
Although false killer whales breed year-round, their breeding peaks in late winter to early spring. Studies suggest they are polygynandrous.
Mating System: polygynandrous (promiscuous)
False killer whales will only have one calf per pregnancy and she carries that calf for 11 to 15.5 months. The calf stays with the mother for 18 to 24 months. Between 18 and 24 months old, the calf is gradually weaned. Sexual maturity occurs in females between 8 and 11 years of age and in males at 8 to 10 years.
In this species and a few others in the family Didelphinidae, if the female doesn't conceive after the first ovulation, she will keep ovulating until she does conceive. After giving birth, the female will not breed again for an average of 6.9 years.
Breeding interval: Females give birth every 6.9 years, on average.
Breeding season: Breeding occurs year-round, but peaks December to January and again in March.
Range number of offspring: 1 (high) .
Average number of offspring: 1.
Range gestation period: 11 to 15.5 months.
Range weaning age: 18 to 24 months.
Range age at sexual or reproductive maturity (female): 8 to 11 years.
Range age at sexual or reproductive maturity (male): 8 to 10 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; viviparous
Average number of offspring: 1.
After false killer whales calves are born, they are cared for and nursed by their mother for up to 24 months. Young are capable of swimming on their own shortly after birth. Young are likely to remain in the same social group with their mother beyond weaning.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); post-independence association with parents; extended period of juvenile learning
