Animal Diversity Web

Ge­o­graphic Range

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. (Shir­i­hai and Jar­rett, 2006)

• Biogeographic Regions
• indian ocean
  • native
• atlantic ocean
  • native
• pacific ocean
  • native
• mediterranean sea
  • native

• Other Geographic Terms
• cosmopolitan

Habi­tat

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. (Wat­son, 1981; Shir­i­hai and Jar­rett, 2006; Wat­son, 1981; Shir­i­hai and Jar­rett, 2006; Wat­son, 1981; Shir­i­hai and Jar­rett, 2006; Wat­son, 1981)

• Habitat Regions
• temperate
• tropical
• saltwater or marine

• Aquatic Biomes
• pelagic
• coastal

• Range depth

  0 to 2000 m

  0.00 to 6561.68 ft

• Average depth

  500 m

  1640.42 ft

Phys­i­cal De­scrip­tion

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. ("Re­view on Small Cetaceans: Dis­tri­b­u­tion, Be­hav­iour, Mi­gra­tion and Threats", 2005; Liebig, et al., 2007; Mi­nasian, et al., 1984; Nowak, 1999; Shir­i­hai and Jar­rett, 2006)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes shaped differently

• Range mass

  916.26 to 1841.59 kg

  2018.19 to 4056.37 lb

• Range length

  3.5 to 6.1 m

  11.48 to 20.01 ft

Re­pro­duc­tion

Al­though false killer whales breed year-round, their breed­ing peaks in late win­ter to early spring. Stud­ies sug­gest they are polyg­y­nan­drous. (Nowak, 1999; Shir­i­hai and Jar­rett, 2006)

• 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. (Per­rin, et al., 2002; Shir­i­hai and Jar­rett, 2006; Sli­jper, 1962)

• Key Reproductive Features
• iteroparous
• year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• induced ovulation
• viviparous

• 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

• Average number of offspring

  1

  AnAge

• 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

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. (Nowak, 1999; Sli­jper, 1962)

• 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

Lifes­pan/Longevity

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. (Shir­i­hai and Jar­rett, 2006; Stacey, et al., 1994)

• Average lifespan
  Status: wild

  60 years

• Average lifespan
  Status: wild

  22.0 years

  Max Planck Institute for Demographic Research

Be­hav­ior

False killer whales are found in groups rang­ing from just a few in­di­vid­u­als to hun­dreds of in­di­vid­u­als. In these large groups they are some­times sep­a­rated into smaller groups or pods, which av­er­age about 18 mem­bers (typ­i­cally 10 to 30). Pods con­sist of all ages and both sexes.

False killer whales often "strand" them­selves in large num­bers. Large strand­ings have been re­ported on beaches in Scot­land, Cey­lon, Zanz­ibar and along the coasts of Britain. It is thought that stranded groups might have been chas­ing groups of seals or sea lions into the shal­lower wa­ters and be­came stuck.

It has been said that false killer whales are as so­cial as pilot whales (Glo­bi­cephala). They ride in the wakes and bow waves of ships. They pre­fer faster-mov­ing ships, but will ride the bow waves on any ves­sel. They are one of the few large mam­mals that leap out of the water over the wake of the ship, which is a use­ful iden­ti­fi­ca­tion at­tribute. (Liebig, et al., 2007; Per­rin, et al., 2002; Shir­i­hai and Jar­rett, 2006; Sli­jper, 1962; Wat­son, 1981)

• Key Behaviors
• natatorial
• motile
• nomadic
• social
• colonial

Home Range

This species is not re­stricted to known home ranges.

Com­mu­ni­ca­tion and Per­cep­tion

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)." (Per­rin, et al., 2002; Wat­son, 1981)

• Communication Channels
• tactile
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• ultrasound
• echolocation
• chemical

Food Habits

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. ("Re­view on Small Cetaceans: Dis­tri­b­u­tion, Be­hav­iour, Mi­gra­tion and Threats", 2005; Per­rin, et al., 2002; Wat­son, 1981)

• Primary Diet
• carnivore
  • piscivore
  • molluscivore

• Animal Foods
• mammals
• fish
• mollusks
• other marine invertebrates

Pre­da­tion

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. (Nowak, 1999; Sli­jper, 1962)

• Known Predators

  • humans (Homo sapiens)

Ecosys­tem Roles

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. (Per­rin, et al., 2002)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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. (Nowak, 1999)

• Positive Impacts
• food

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

These whales will eat fish off of fish­ing lines and out of nets of com­mer­cial fish­ing op­er­a­tions. (Nowak, 1999; Per­rin, et al., 2002)

Con­ser­va­tion Sta­tus

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. (Nowak, 1999)

• IUCN Red List

  Data Deficient
  More information

• IUCN Red List

  Data Deficient
  More information

• US Federal List

  No special status

• CITES

  Appendix II

• State of Michigan List

  No special status

Other Com­ments

This species was thought to be ex­tinct until ap­prox­i­mately 50 years ago, be­cause only skulls and other bones washed ashore. (Shir­i­hai and Jar­rett, 2006)

Con­trib­u­tors

Tanya Dewey (ed­i­tor), An­i­mal Di­ver­sity Web.

Kevin Hat­ton (au­thor), Rad­ford Uni­ver­sity, Karen Pow­ers (ed­i­tor, in­struc­tor), Rad­ford Uni­ver­sity.

Ref­er­ences

Con­ven­tion of Mi­gra­tory Species. Re­view on Small Cetaceans: Dis­tri­b­u­tion, Be­hav­iour, Mi­gra­tion and Threats. None. Ger­many: Boris Michael Culik, Marco Bar­bi­eri. 2005. Ac­cessed Sep­tem­ber 20, 2007 at http://​www.​cms.​int/​reports/​small_​cetaceans/​data/​P_​crassidens/​p_​crassidens.​htm.

Liebig, P., K. Flessa, T. Tay­lor. 2007. Tapho­nomic Vari­a­tion De­spite Cat­a­strophic Mor­tal­ity: Analy­sis of a Mass Strand­ing of False Killer Whales(Pseudorca cras­si­dens), Gulf of Cal­i­for­nia, Mex­ico. Palaios, Vol­ume 22, Issue 4: 384-391.

Mi­nasian, S., K. Bal­comb, III, L. Fos­ter. 1984. The World's Whales. New York and Lon­don: W.W. Nor­ton & Com­pany.

Nowak, R. 1999. Walker's Mam­mals of the World. Bal­ti­more and Lon­don: The John Hop­kins Uni­ver­sity Press.

Per­rin, W., B. Würsig, J. Thewis­sen. 2002. En­cy­clo­pe­dia of Ma­rine Mam­mals. United States of Amer­ica: Aca­d­e­mic Press.

Shi­rai, K., T. Saki. 1997. Haema­to­log­i­cal Find­ings in Cap­tive Dol­phins and Whales. Aus­tralian Vet­eri­nary Jour­nal, 75/7: 512-514. Ac­cessed Oc­to­ber 18, 2007 at http://​www.​ava.​com.​au/​avj/​jul97/​512.​htm.

Shir­i­hai, H., B. Jar­rett. 2006. Whales, Dol­phins and Other Ma­rine Mam­mals of the World. Prince­ton and Ox­ford: Prince­ton Uni­ver­sity Press.

Sli­jper, E. 1962. Whales. New York: Basic Books Inc..

Stacey, P., S. Leather­wood, R. Baird. 1994. Pseudorca cras­si­dens. Mam­malian Species, 456: 1-6.

Wat­son, L. 1981. Sea Guide To Whales of the World. New York, NY: El­se­vier-Du­ton Pub­lish­ing Co Inc.