false killer whale

File:Pseudorca crassidens head.jpg

The false killer whale was first described by British paleontologist and biologist Richard Owen in his 1846 book, A history of British fossil mammals and birds, based on a fossil skull discovered in 1843. This specimen was unearthed from the Lincolnshire Fens near Stamford in England, a subfossil deposited in a marine environment that existed around 126,000 years ago. The skull was reported as present in a number of museum collections, but noted as lost by William Henry Flower in 1884.Hershkovitz, P. 1966. Catalog of living whales. Bulletin of the United States National Museum 246: viii 1–259 [81] Owen compared the skull to those of the long-finned pilot whale (Globicephala melas), beluga whale (Delphinapterus leucas), and Risso's dolphin (Grampus griseus)–in fact, he gave it the nickname "thick toothed grampus" in light of this and assigned the animal to the genus Phocaena (a genus of porpoises) which Risso's dolphin was also assigned to in 1846. The species name crassidens means "thick toothed".{{cite book|last=Owen|first=R.|author-link=Richard Owen|title = A history of British fossil mammals and birds |year = 1846 |pages = 516–520|publisher=J. Van Voorst|url = https://archive.org/stream/historyofbritish00owen#page/516}}

In 1846, zoologist John Edward Gray put the false killer whale in the genus Orcinus, which had been known as the killer whale (Orcinus orca). Until 1861, when the first carcasses washed up on the shores of Kiel Bay, Denmark, the species was presumed extinct. Based on these and a pod that beached itself three months later in November, zoologist Johannes Theodor Reinhardt moved the species in 1862 to the newly erected genus Pseudorca, which established it as being neither a porpoise nor a killer whale.{{cite book|chapter-url=https://archive.org/stream/recentmemoirsonc00esch#page/190|first=J.|last=Reinhardt|author-link=Johannes Theodor Reinhardt|year=1866|chapter=Pseudorca crassidens|title=Recent memoirs on the Cetacea|editor1-first=D. F.|editor1-last=Eschricht|editor2-first=W.|editor2-last=Lilljeborg|editor3-first=J.|editor3-last=Reindhardt|pages=190–218}}{{cite book|editor1-first=S. H.|editor1-last=Ridgeway|editor2-first=R.|editor2-last=Harrison|editor3-first=R. J.|editor3-last=Harrison|first1=D. K.|last1=Odell|first2=K. M.|last2=McClune|year=1981|chapter=False killer whale Pseudorca crassidens (Owen, 1946)|title=Handbook of marine mammals: the second book of dolphins and the porpoises|publisher=Elsevier|isbn=978-0-12-588506-5|chapter-url={{google books|plainurl=yes|id=At4jWmmaq6QC|page=213}}}} The name "false killer whale" comes from the apparent similarity between its skull and that of the killer whale.{{cite book|first=R. W.|last=Baird|year=2009|chapter=False Killer Whale: Pseudorca crassidens|title=Encyclopedia of marine mammals|editor1-first=W. F.|editor1-last=Perrin|editor2-first=B.|editor2-last=Würsig|editor3-first=J. G. M.|editor3-last=Thewissen|publisher=Academic Press|pages=405–406|chapter-url={{google books|plainurl=yes|id=2rkHQpToi9sC|page=405}}|isbn=978-0-08-091993-5}}

The false killer whale is in the family Delphinidae (oceanic dolphins). It is in the subfamily Globicephalinae; its closest living relatives are Risso's dolphin, the melon-headed whale (Peponocephala electra), the pygmy killer whale (Feresa attenuata), pilot whales (Globicephala spp.), and possibly snubfin dolphins (Orcaella spp.).{{cite journal|first1=H. A.|last1=Cunha|first2=L. C.|last2=Moraes|first3=B. V.|last3=Medeiros|first4=J.|last4=Lailson-Brito, Jr|first5=V. M. F.|last5=da Silva|first6=A. M.|last6=Solé-Cava|first7=C. G.|last7=Schrago|year=2011|title=Phylogenetic Status and Timescale for the Diversification of Steno and Sotalia Dolphins|journal=PLOS ONE|volume=6|issue=12|pages=e28297|doi=10.1371/journal.pone.0028297|pmid=22163290|pmc=3233566|bibcode=2011PLoSO...628297C|doi-access=free}} William Henry Flower suggested in 1884 and later abandoned a distinction between northern and southern false killer whales. Paules Edward Pieris Deraniyagala proposed a subspecies, P. c. meridionalis, in 1945, though without enough justification. There are currently no recognized subspecies.{{cite journal|first1=P. J.|last1=Stacey|first2=S.|last2=Leatherwood|first3=R. W.|last3=Baird|year=1994|title=Pseudorca crassidens|journal=Mammalian Species|number=456|pages=1–6|url=http://www.cascadiaresearch.org/oldsite/robin/FKWmamspec.pdf|doi=10.2307/3504208|jstor=3504208|s2cid=253993005 }} Still, individuals in populations around the world can have different skull structure and vary in average length with Japanese false killers found to be 10–20% larger than South African ones.{{cite journal|first1=I. M.|last1=Ferreira|first2=T.|last2=Kasuya|first3=H.|last3=Marsh|first4=P. B.|last4=Best|year=2013|title=False killer whales (Pseudorca crassidens) from Japan and South Africa: Differences in growth and reproduction|journal=Marine Mammal Science|volume=30|issue=1|pages=64–84|doi=10.1111/mms.12021|hdl=2263/50452|hdl-access=free}} It can hybridize with the bottlenose dolphin (Tursiops truncatus) to produce fertile offspring called "wholphins".{{cite news|first=S. B.|last=Carroll|author-link=Sean B. Carroll|date=13 September 2010|title=Hybrids may thrive where parents fear to tread|work=New York Times}}

File:The False Killer Whale (Pseudorca crassidens) (http-www.bluekaymahahual.com) - panoramio.jpg

False killer whales are large marine predators. They are the fourth-largest extant species of oceanic dolphin, exceeded in size only by the orca and the two species of pilot whales. Males are about 10–15 % larger than females:{{cite book |last1=Foley |first1=Charles |last2=Foley |first2=Lara |last3=Lobora |first3=Alex |last4=Luca |first4=Daniela De |last5=Msuha |first5=Maurus |last6=Davenport |first6=Tim R. B. |last7=Durant |first7=Sarah M. |title=A Field Guide to the Larger Mammals of Tanzania |date=8 June 2014 |publisher=Princeton University Press |isbn=978-1-4008-5280-2 |page=252 |url=https://books.google.com/books?id=dt6QAwAAQBAJ |language=en}} females reach a maximum size of {{cvt|5|m|ft}} in length and {{cvt|1200|kg|lb}} in weight, and males {{cvt|6|m|ft}} long and {{cvt|2300|kg|lb}}.{{cite web |title=False killer whale |url=https://uk.whales.org/whales-dolphins/species-guide/false-killer-whale/ |website=Whale & Dolphin Conservation UK}} Newborns can be {{cvt|1.5|-|2.1|m|ft|0}} long.{{Cite web| title = False killer whale (Pseudorca crassidens)| publisher = Marine Species Identification Portal| url = http://species-identification.org/species.php?species_group=marine_mammals&id=101| access-date = 26 January 2013| archive-date = 30 June 2018| archive-url = https://web.archive.org/web/20180630052823/http://species-identification.org/species.php?species_group=marine_mammals&id=101| url-status = dead}} Coloration is black or dark gray, slightly lighter on the underside. The body is slender with an elongated, tapered head without a beak. The dorsal fin is sickle-shaped; the flippers are narrow, short, and pointed, with a distinctive bulge on the leading edge of the flipper. Body temperature ranges from {{convert|36|–|37.2|C|F}}, increasing during activity. The teeth are conical; there are 14–21 in the upper jaw and 16–24 in the lower.

A false killer whale reaches physical maturity at 8 to 14 years; maximum age in captivity is 57 years for males and 62 for females. Sexual maturity happens at 8 to 11 years. In one population, calving was at 7-year intervals; calving can occur year-round, though it usually occurs in late winter. Gestation takes ~15 months; lactation, 9 months to 2 years.{{cite journal|first1=L.|last1=Riccialdelli|first2=R. N. P.|last2=Goodall|year=2015|title=Intra-specific trophic variation in false killer whales (Pseudorca crassidens) from the southwestern South Atlantic Ocean through stable isotopes analysis|journal=Mammalian Biology |volume=80 |issue=4 |pages=298–302 |doi=10.1016/j.mambio.2015.01.003 |bibcode=2015MamBi..80..298R |hdl=11336/5439|hdl-access=free}} The false killer and pilot whales have a sizable lifespan after menopause, which typically occurs between 45 and 55.{{cite journal|first1=T.|last1=Photopoulou|first2=I. M.|last2=Ferreira|first3=P. B. |last3=Best|first4=T.|last4=Kasuya|first5=H.|last5=Marsh|year=2017|title=Evidence for a postreproductive phase in female false killer whales Pseudorca crassidens|journal=Frontiers in Zoology|volume=14|issue=30|pages=30|doi=10.1186/s12983-017-0208-y|pmid=28649267|pmc=5479012|arxiv=1606.04519 |doi-access=free }} As a toothed whale, a false killer can echolocate to navigate and find prey, using its melon organ in the forehead to create sound.{{cite journal|first1=W. W. L.|last1=Au|first2=J. L.|last2=Pawloski|first3=P. E.|last3=Nachtigall|year=1995|title=Echolocation signals and transmission beam pattern of a false killer whale (Pseudorca crassidens)|journal=Journal of the Acoustical Society of America|volume=98|issue=51|pages=51–59|doi=10.1121/1.413643|pmid=7608405|bibcode=1995ASAJ...98...51A}}{{Cite journal |last=Marlee |first=Breese |date=2012 |title=Echolocation beam focusing in the false killer whale (Pseudorca crassidens) |journal=Frontiers in Behavioral Neuroscience |volume=6 |doi=10.3389/conf.fnbeh.2012.27.00161 |issn=1662-5153|doi-access=free }}{{Cite journal |last1=Kloepper |first1=Laura |last2=Nachtigall |first2=Paul |last3=Donahe |first3=Megan |last4=Breese |first4=Marlee |date=April 15, 2012 |title=Active echolocation beam focusing in the false killer whale, Pseudorca crassidens |url=https://journals.biologists.com/jeb/article/215/8/1306/11323/Active-echolocation-beam-focusing-in-the-false |journal=Journal of Experimental Biology |volume=215 |issue=8 |pages=1306–1312|doi=10.1242/jeb.066605 |pmid=22442368 |s2cid=207170104 |doi-access=free |url-access=subscription }} The melon is larger in males than in females.

File:Bottlenose dolphins and false killer whales.gifs (Tursiops truncatus) and false killer whales]]

The false killer whale has been known to interact non-aggressively with some dolphins: the common bottlenose dolphin, the Pacific white-sided dolphin (Lagenorhynchus obliquidens), the rough-toothed dolphin (Steno bredanensis), the pilot whales, the melon-headed whale, the pantropical spotted dolphin (Stenella attenuata), the pygmy killer whale, and Risso's dolphin.{{Cite journal |last1=Brown |first1=David H. |last2=Caldwell |first2=David K. |last3=Caldwell |first3=Melba C. |date=1966-04-04 |title=Observations on the behavior of wild and captive false killer whales, with notes on associated behavior of other genera of captive delphinids |journal=Contributions in Science |volume=95 |pages=1–32 |doi=10.5962/p.241085 |s2cid=91933110 |issn=0459-8113|doi-access=free }}{{Cite journal |last1=Zaeschmar |first1=Jochen R. |last2=Dwyer |first2=Sarah L. |last3=Stockin |first3=Karen A. |date=2012-07-09 |title=Rare observations of false killer whales (Pseudorca crassidens) cooperatively feeding with common bottlenose dolphins (Tursiops truncatus) in the Hauraki Gulf, New Zealand |url=http://dx.doi.org/10.1111/j.1748-7692.2012.00582.x |journal=Marine Mammal Science |volume=29 |issue=3 |pages=555–562 |doi=10.1111/j.1748-7692.2012.00582.x |s2cid=83714092 |issn=0824-0469|url-access=subscription }} They have been shown to engage in depredation at fisheries with killer whales (Orcinus orca), though their diets differ with the killer whales and false killer whales preferring swordfish and smaller fish respectively.{{Cite journal |last1=Passadore |first1=Cecilia |last2=Domingo |first2=Andrés |last3=Secchi |first3=Eduardo R. |date=2015-01-16 |title=Depredation by killer whale (Orcinus orca) and false killer whale (Pseudorca crassidens) on the catch of the Uruguayan pelagic longline fishery in Southwestern Atlantic Ocean |url=http://dx.doi.org/10.1093/icesjms/fsu251 |journal=ICES Journal of Marine Science |volume=72 |issue=5 |pages=1653–1666 |doi=10.1093/icesjms/fsu251 |issn=1095-9289|url-access=subscription }}

A false killer may respond to distress calls and protect other species from predators, aid in childbirth by helping to remove the afterbirth, and has been known to interact sexually with bottlenose dolphins (see Wholphin) and pilot whales, including homosexually. It has been known to form mixed-species pods with those dolphins, probably due to shared feeding grounds. In Japan, these only occur in winter, suggesting it is tied to seasonal food shortages.

A pod near Chile had a {{convert|15|kph|mph|adj=on|abbr=on}} cruising speed, and false killer whales in captivity were recorded to have a maximum speed of {{convert|26.9|–|28.8|kph|mph|abbr=on}}, similar to a bottlenose dolphin. Diving behavior is not well recorded, but one individual near Japan dove for 12 minutes to a depth of {{convert|230|m|ft|abbr=on}}.{{cite journal|first1=S.|last1=Minamikawa|first2=H.|last2=Watanabe|first3=T.|last3=Iwasaki|year=2011|title=Diving behavior of a false killer whale, Pseudorca crassidens, in the Kuroshio–Oyashio transition region and the Kuroshio front region of the western North Pacific|journal=Marine Mammal Science|volume=29|issue=1|pages=177–185|doi=10.1111/j.1748-7692.2011.00532.x}} In Japan, one individual had a documented dive of {{convert|600|m|ft|abbr=on}}, and one in Hawaii {{convert|927.5|m|ft|abbr=on}}, comparable to pilot whales and other similarly sized dolphins. Its maximum dive time is likely 18.5 minutes.

The false killer travels in large pods, evidenced by mass strandings; usually 10 to 20 members, though these smaller groups can be part of larger groups; it is highly social and can travel in groups of more than 500 whales.{{Cite journal |last1=Caldwell |first1=David K. |last2=Caldwell |first2=Melba C. |last3=Walker |first3=Cecil M. |date=August 1970 |title=Mass and Individual Strandings of False Killer Whales, Pseudorca crassidens, in Florida |url=http://dx.doi.org/10.2307/1378415 |journal=Journal of Mammalogy |volume=51 |issue=3 |pages=634 |doi=10.2307/1378415 |jstor=1378415 |issn=0022-2372|url-access=subscription }} These large groups may break up into smaller family groups of 4 to 6 members while feeding. Members stay with the pod long-term, some recorded as 15 years, and, indicated by mass strandings, share strong bonds with other members. It is thought it has a matrifocal family structure, with mothers heading the pod instead of the father, like in sperm whales and pilot whales. Different populations around the world have different vocalizations, similar to other dolphins. The false killer whale is probably polygynous, with males mating with multiple females.{{cite journal|first1=S. J.|last1=Chivers|first2=R. W.|last2=Baird|first3=D. J.|last3=McSweeney|first4=D. L.|last4=Webster|first5=N. M.|last5=Hedrick|first6=J. C.|last6=Salinas|year=2007|title=Genetic variation and evidence for population structure in eastern North Pacific false killer whales (Pseudorca crassidens)|journal=Canadian Journal of Zoology|volume=85|issue=7|pages=783–794|doi=10.1139/Z07-059|bibcode=2007CaJZ...85..783C |url=https://swfsc.noaa.gov/uploadedFiles/Divisions/PRD/Publications/Chivers%20et%20al_2007_CJZ_PcraGenetics.pdf}}

File:Anim2620 (33910331754).jpg]]

The false killer whale is an active predator, inhabiting tropical and subtropical waters.{{cite journal |last1=Riccialdelli |first1=Luciana |last2=Goodall |first2=Natalie |title=Intra-specific trophic variation in false killer whales (Pseudorca crassidens) from the southwestern South Atlantic Ocean through stable isotopes analysis |journal=Mammalian Biology |date=1 August 2015 |volume=80 |issue=4 |pages=298–302 |doi=10.1016/j.mambio.2015.01.003 |bibcode=2015MamBi..80..298R |url=https://www.sciencedirect.com/science/article/abs/pii/S1616504715000051 |issn=1616-5047|hdl=11336/5439 |hdl-access=free }}{{cite journal |last1=Haro |first1=Daniela |last2=Riccialdelli |first2=Luciana |last3=Blank |first3=Olivia |last4=Matus |first4=Ricardo |last5=Sabat |first5=Pablo |title=Estimating the isotopic niche of males and females of false killer whales (Pseudorca crassidens) from Magellan Strait, Chile |journal=Marine Mammal Science |date=July 2019 |volume=35 |issue=3 |pages=1070–1082 |doi=10.1111/MMS.12564 |bibcode=2019MMamS..35.1070H |s2cid=92280892 |url=https://ri.conicet.gov.ar/handle/11336/101723 |issn=0824-0469|url-access=subscription }} Generally, the false killer whale targets a wide array of squid and fish of various sizes during daylight hours.{{cite journal|first1=M. K.|last1=Alonso|first2=S. N.|last2=Pedraza|first3=A. C. M.|last3=Schiavini|first4=R. N. P.|last4=Goodman|first5=E. A.|last5=Crespo|year=1999|title=Stomach contents of false killer whales (Pseudorca crassidens) stranded on the coasts of the Strait of Magellan|journal=Marine Mammal Science|volume=15|issue=3|pages=712–724|doi=10.1111/j.1748-7692.1999.tb00838.x}} They typically target large species of fish, such as mahi-mahi, wahoo and tuna. They are also known to prey on marine mammals, such as some species of dolphins and whales.{{cite web |title=WDC |url=https://us.whales.org/species-guide/false-killer-whale |website=us.whales.org |access-date=7 October 2018}}{{cite web |title=False killer whale |url=https://iwc.int/about-whales/whale-species/false-killer-whale |website=iwc.int |language=en}}{{cite book |last1=Stuart |first1=Chris |title=Stuarts' Field Guide to the Larger Mammals of Africa |date=1 July 2017 |publisher=Penguin Random House South Africa |isbn=978-1-77584-276-7 |url=https://books.google.com/books?id=2w1bDwAAQBAJ |language=en}} In captivity, it eats 3.4 to 4.3% of its body weight per day. A video taken in 2016 near Sydney shows a group hunting a juvenile shark.{{cite web|url=https://www.earthtouchnews.com/natural-world/predator-vs-prey/drone-films-false-killer-whales-hunting-down-a-shark/|first=N.|last=Hubbard|date=10 May 2016|title=Drone films false killer whales hunting down a shark|website=Earth Touch News Network|access-date=2 August 2018}} It sometimes discards the tail, gills, and stomach of captured fish, and pod members have been known to share food.

In the Eastern Pacific, the false killer whale has been known to target smaller dolphins during tuna purse-seine fishing operations; there are attacks on sperm whales (Physeter macrocephalus), and one instance against a humpback whale (Megaptera novaeangliae) calf. Killer whales are known to prey on the false killer, and it also possibly faces a threat from large sharks, though there are no documented instances.{{cite journal|first1=D. M.|last1=Palacios|first2=B. R.|last2=Mate|year=1996|title=Attack by false killer whales (Pseudorca crassidens) on sperm whales (Physeter macrocephalus) in the Galápagos Islands|journal=Marine Mammal Science|volume=12|issue=4|pages=582–587|doi=10.1111/j.1748-7692.1996.tb00070.x|bibcode=1996MMamS..12..582P }}

The false killer whale is known to host parasites: trematode Nasitrema in the sinuses, nematode Stenurus in the sinuses and lungs, an unidentified crassicaudine nematode in the sinuses, stomach nematodes Anisakis simplex and Anisakis typica, acanthocephalan worm Bolbosoma capitatum in the intestines, whale lice Syncyamus pseudorcae and Isocyamus delphinii, and the whale barnacle Xenobalanus globicipitis. Some strandings had whales with large Bolbosoma infestations, such as the 1976 and 1986 strandings in Florida.

The false killer whale appears to have a widespread presence in tropical and semitropical oceans.{{Cite journal |last1=ACEVEDO-GUTIÉRREZ |first1=ALEJANDRO |last2=BRENNAN |first2=BERNARD |last3=RODRIGUEZ |first3=PATRICIA |last4=THOMAS |first4=MOLLY |title=Resightings and Behavior of False Killer Whales ( Pseudorca Crasszdens ) in Costa Rica |date=April 1997 |url=http://dx.doi.org/10.1111/j.1748-7692.1997.tb00634.x |journal=Marine Mammal Science |volume=13 |issue=2 |pages=307–314 |doi=10.1111/j.1748-7692.1997.tb00634.x |bibcode=1997MMamS..13..307A |issn=0824-0469|url-access=subscription }} The species has been found in temperate waters, but these occurrences were possibly stray individuals, or associated with warm water events. It generally does not go beyond 50°N or below 50°S.{{Cite journal|last1=Halpin|first1=Luke R.|last2=Towers|first2=Jared R.|last3=Ford|first3=John K. B.|date=2018-04-20|title=First record of common bottlenose dolphin (Tursiops truncatus) in Canadian Pacific waters|journal=Marine Biodiversity Records|volume=11|issue=1 |pages=3|doi=10.1186/s41200-018-0138-1|doi-access=free|bibcode=2018MBdR...11....3H }} It usually inhabits open ocean and deep-water areas, though it may frequent coastal areas near oceanic islands. Distinct populations inhabit the seas near the Hawaiian Islands{{Cite journal |last1=Baird |first1=RW |last2=Schorr |first2=GS |last3=Webster |first3=DL |last4=McSweeney |first4=DJ |last5=Hanson |first5=MB |last6=Andrews |first6=RD |date=2010-02-09 |title=Movements and habitat use of satellite-tagged false killer whales around the main Hawaiian Islands |journal=Endangered Species Research |volume=10 |pages=107–121 |doi=10.3354/esr00258 |s2cid=54074273 |issn=1863-5407|doi-access=free }}{{Cite journal |last1=Baird |first1=Robin W. |last2=Gorgone |first2=Antoinette M. |last3=McSweeney |first3=Daniel J. |last4=Webster |first4=Daniel L. |last5=Salden |first5=Dan R. |last6=Deakos |first6=Mark H. |last7=Ligon |first7=Allan D. |last8=Schorr |first8=Gregory S. |last9=Barlow |first9=Jay |last10=Mahaffy |first10=Sabre D. |date=July 2008 |title=False killer whales (Pseudorca crassidens) around the main Hawaiian Islands: Long-term site fidelity, inter-island movements, and association patterns |url=http://dx.doi.org/10.1111/j.1748-7692.2008.00200.x |journal=Marine Mammal Science |volume=24 |issue=3 |pages=591–612 |doi=10.1111/j.1748-7692.2008.00200.x |bibcode=2008MMamS..24..591B |s2cid=12769431 |issn=0824-0469|url-access=subscription }} and in the eastern North Pacific.{{Cite journal |last1=Chivers |first1=Susan J. |last2=Baird |first2=Robin W. |last3=McSweeney |first3=Daniel J. |last4=Webster |first4=Daniel L. |last5=Hedrick |first5=Nicole M. |last6=Salinas |first6=Juan Carlos |date=July 2007 |title=Genetic variation and evidence for population structure in eastern North Pacific false killer whales (Pseudorca crassidens) |url=http://dx.doi.org/10.1139/z07-059 |journal=Canadian Journal of Zoology |volume=85 |issue=7 |pages=783–794 |doi=10.1139/z07-059 |bibcode=2007CaJZ...85..783C |issn=0008-4301|url-access=subscription }}

The false killer whale is thought to be common around the world, though no total estimate has been made.{{cite journal|first1=P. J.|last1=Stacey|first2=R. W.|last2=Baird|year=1991|title=Status of the false killer whale, Pseudorca crassidens, in Canada|journal=Canadian Field-Naturalist|volume=105|issue=2|pages=189–197|doi=10.5962/p.357997 |url=https://www.researchgate.net/publication/285069079|doi-access=free}} The population in the Eastern Pacific is probably in the low tens-of-thousands,{{cite web|url=http://cpps.dyndns.info/cpps-docs-web/planaccion/docs2011/oct/turismo_biodiv/Doc.7.Dolphins_whales_porpoises.pdf|first1=R. R.|last1=Reeves|first2=B. D.|last2=Smith|first3=E. A.|last3=Crespo|first4=G. N.|last4=di Sciara|year=2003|title=Dolphins, Whales, and Porpoises: 2002-2010 Conservation Action Plan for the World's Cetaceans|publisher=IUCN|access-date=3 August 2018|archive-date=4 August 2018|archive-url=https://web.archive.org/web/20180804075822/http://cpps.dyndns.info/cpps-docs-web/planaccion/docs2011/oct/turismo_biodiv/Doc.7.Dolphins_whales_porpoises.pdf|url-status=dead}} and ~16,000 near China and Japan.{{cite web|url=http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=48|title=Pseudorca crassidens –False killer whale|publisher=Australia Government Department of the Environment and Energy|access-date=3 August 2018}} The population around Hawaii has been declining.

File:Pseudorca crassidens at Okichan Theater 20070201.jpg]]

The false killer whale is known to be much more adaptable in captivity than other dolphins, being easily trained and highly sociable with other species, and as such it has been kept in several public aquariums around the world, such as in Japan, the United States, the Netherlands, Hong Kong, and Australia. Individuals were mainly captured off California and Hawaii, and then in Japan and Taiwan after 1980.{{cite journal|url=https://nhm.org/site/sites/default/files/pdf/contrib_science/CS95.pdf|archive-url=https://web.archive.org/web/20160322042000/https://nhm.org/site/sites/default/files/pdf/contrib_science/CS95.pdf|archive-date=2016-03-22|first1=D. H.|last1=Brown|first2=D. H.|last2=Caldwell|first3=M. B.|last3=Caldwell|year=1966|title=Observations on the wild and captive false killer whales, with notes on associated behavior of other genera of captive delphinids|journal=Los Angeles County Museum|number=95}} It has also been successfully bred in captivity. Chester, an orphaned calf that had been stranded near Tofino in 2014 and rescued by Vancouver Aquarium, probably died from a bacterial erysipelas infection in 2017 at the age of approximately three and a half.{{cite news|first=N.|last=Eagland|date=24 November 2017|title=Only one cetacean remains in Vancouver Aquarium's tanks after a false killer whale died Friday morning|work=Vancouver Sun|access-date=2 August 2018|url=https://vancouversun.com/news/local-news/chester-the-false-killer-whale-dies-at-vancouver-aquarium}}{{cite news|url=https://globalnews.ca/news/3890954/chester-false-killer-whale-necropsy/|date=30 November 2017|title=False killer whale 'Chester' may have died from bacterial infection: preliminary necropsy report|work=Global News|access-date=2 August 2017}}

The false killer has been known to approach and offer fish it has caught to humans diving or boating. It also takes fish off hooks, which sometimes leads to entanglement or swallowing the hook. Entanglement can cause drowning, loss of circulation to an appendage, or impede the animal's ability to hunt, and swallowing the hook can puncture the digestive tract or can become a blockage. In Hawaii, this is likely leading to the decline in local populations, reducing them by 75% from 1989 to 2009. The false killer is more susceptible to organochloride buildup than other dolphins, being higher up on the food chain, and stranded individuals around the world show higher levels than other dolphins. It has been known to ride the wakes of large boats, which could put it at risk of hitting the propeller.{{cite web|url=https://www.mmc.gov/wp-content/uploads/killerwhale_review_mmc09.pdf|first=R. W.|last=Baird|date=23 December 2009|title=A review of false killer whales in Hawaiian waters: biology, status, and risk factors|website=Cascadia Research Collective|access-date=2 August 2018}}{{cite web|first=J. R.|last=Zaeschmar|year=2014|title=False killer whales (Pseudorca crassidens) in New Zealand waters|url=https://www.coastalmarineresearchgroup.com/PDFs/Zaeschmar%20MSc_2015.pdf|publisher=Massey University|access-date=2 August 2018|archive-date=3 August 2018|archive-url=https://web.archive.org/web/20180803074251/https://www.coastalmarineresearchgroup.com/PDFs/Zaeschmar|url-status=usurped}}

In a few Japanese villages, the false killer is killed in harpooning hunts and drive hunts using sound to herd individuals together and cause a mass stranding or corral them into nets before being killed.{{cite journal|first1=R. L.|last1=Brownell Jr.|first2=D. P.|last2=Nowacek|first3=K.|last3=Ralls|year=2008|title=Hunting cetaceans with sound: a worldwide review|journal=Journal of Cetacean Research and Management|volume=10|issue=1|pages=81–88|doi=10.47536/jcrm.v10i1.663 |s2cid=44966372 |url=https://repository.si.edu/bitstream/handle/10088/8052/nzp_Brownell_et_al._2008_HWS.pdf}} A total of 24 false killer whale were hunted in Japan from 2010 to 2023.{{Cite web |author=|title=令和3年度 国際漁業資源の現況 小型鯨類の漁業と資源調査（総説）|page=48 9|url=https://kokushi.fra.go.jp/R03/R03_48_whalesS-R.pdf|archive-url=https://web.archive.org/web/20220702230448/https://kokushi.fra.go.jp/R03/R03_48_whalesS-R.pdf|publisher=Fisheries Agency (Japan)|date=|archive-date=2 July 2022|access-date=10 February 2025 }}{{Cite web |author=|title=令和5年度 国際漁業資源の現況 小型鯨類の漁業と資源調査（総説）|page=48 9|url=https://kokushi.fra.go.jp/R05/R05_48_whalesS-R.pdf|archive-url=https://web.archive.org/web/20250118131522/https://kokushi.fra.go.jp/R05/R05_48_whalesS-R.pdf|publisher=Fisheries Agency (Japan)|date=|archive-date=18 January 2025|access-date=11 February 2025 }}{{Cite web |author=|title=捕鯨をめぐる情勢|page=9|url=https://www.jfa.maff.go.jp/j/whale/attach/pdf/index-89.pdf|archive-url=https://web.archive.org/web/20250210015010/https://www.jfa.maff.go.jp/j/whale/attach/pdf/index-89.pdf|publisher=Fisheries Agency (Japan)|date=January 2025|archive-date=10 February 2025|access-date=10 February 2025 }}

{{See also|Cetacean stranding}}

File:Las Pseudo Orcas de Mar del Plata 3 Playa Bristol.jpg, Argentina in 1946, the largest false killer whale stranding]]

The false killer whale regularly beaches itself, for reasons largely unknown, on coasts around the world, with the largest stranding consisting of 835 individuals on 9 October 1946 at Mar del Plata in Argentina. Unlike other dolphins, but similar to other globicephalines, the false killer usually mass strands in pods, leading to such high mortality rates. These can also occur in temperate waters outside its normal range, such as with the mass strandings in Britain in 1927, 1935, and 1936.{{cite journal|first=D. E.|last=Sergeant|year=1982|title=Mass strandings of toothed whales (Odontoceti) as a population phenomenon|journal=The Scientific Reports of the Whales Research Institute|volume=34|page=18|url=http://www.icrwhale.org/pdf/SC0341-47.pdf}}

File:1986 beached whales in Flinders Bay (2).JPG beaching in 1986]]

The 30 July 1986 mass stranding of 114 false killers in Flinders Bay, Western Australia was widely watched as volunteers and the newly created Department of Conservation and Land Management (CALM) saved 96 whales, and founded an informal network for whale strandings.{{cite news| url=http://www.abc.net.au/local/stories/2011/06/07/3237977.htm | work=ABC | location=South West WA | title=Whale rescue in 1986 changed not just the people who were there | date=7 June 2011 | access-date=8 July 2012}}{{cite news| url=https://thewest.com.au/news/australia/world-watched-as-wa-town-saved-the-whales-ng-ya-160035 | work=The West Australian | title=World watched as WA town saved the whales | date=19 July 2011 | access-date=8 July 2012}} The 2 June 2005 Geographe Bay stranding of 120 whales in Western Australia, the fourth in the bay, was caused by a storm preventing the animals from seeing the shoreline; this also caused a rescue effort of 1,500 volunteers by CALM.{{cite web|url=http://www.naturebase.net/news/news.cgi?item=1117793828|archive-url=https://web.archive.org/web/20060907085115/http://www.naturebase.net/news/news.cgi?item=1117793828|url-status=dead|archive-date=7 September 2006|date=6 March 2005|title=No further sightings of stranded whales|publisher=Department of Conservation and Land Management|access-date=2 August 2018}}{{cite journal|first1=S. L.|last1=Chambers|first2=R. N.|last2=James|year=2005|title=Sonar termination as a cause of mass cetacean strandings in Geographe Bay, south-western Australia|journal=Proceedings of the Australian Acoustical Society|pages=391–398|url=http://www.biophysics.uwa.edu.au/Bioacoustics/articles/ChambersJames2005.pdf|access-date=3 August 2018|archive-url=https://web.archive.org/web/20061004062509/http://www.biophysics.uwa.edu.au/Bioacoustics/articles/ChambersJames2005.pdf|archive-date=4 October 2006|url-status=dead}}

Since 2005, there have been seven mass strandings of false killer whales in New Zealand involving more than one individual, the largest on 8 April 1943 on the Māhia Peninsula with 300 stranded, and 31 March 1978 in Manukau Harbour with 253 stranded.

Whale strandings are rare in southern Africa, but mass strandings in this area are typically associated with the false killer, with mass strandings averaging at 58 individuals. Hot-spots for mass stranding exist along the coast of the Western Cape in South Africa; the most recent on 30 May 2009 near the village of Kommetjie with 55 individuals.{{cite journal|first1=S.|last1=Kirkman|first2=M. A.|last2=Meyer|first3=M.|last3=Thornton|year=2010|title=False killer whale Pseudorca crassidens mass stranding at Long Beach on South Africa's Cape Peninsula, 2009|journal=African Journal of Marine Science|volume=32|issue=1|pages=167–170|doi=10.2989/1814232X.2010.481168|bibcode=2010AfJMS..32..167K |s2cid=84702502|url=https://www.researchgate.net/publication/236877752}}

On 14 January 2017, a pod of ~100 beached themselves in Everglades National Park, Florida, US; the remoteness of the area was detrimental to rescue efforts, causing the deaths of 81 whales. The other two strandings in Florida were in 1986 with three beached whales from a pod of 40 in Cedar Key, and 1980 with 28 stranded in Key West.{{cite news|url=https://www.miamiherald.com/news/local/environment/article126855309.html|first=J.|last=Staletovich|date=16 January 2017|title=Mysterious stranding kills 81 false killer whales off Southwest Florida|work=Miami Herald|access-date=2 August 2018}}

The false killer whale is covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS), and the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS). The species is further included in the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU) and the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU).{{Cite web|url=https://accobams.org/|title=Accobams News|access-date=20 October 2021|archive-date=16 October 2021|archive-url=https://web.archive.org/web/20211016171724/https://accobams.org/|url-status=live}}

No accurate global estimates for the false killer whale exist, so the species is listed as Near Threatened by the IUCN Redlist. In November 2012, the United States' National Oceanic and Atmospheric Administration recognized the Hawaiian population of false killers, comprising ~150 whales, as endangered.{{cite web | url=http://www.courthousenews.com/2012/11/27/52548.htm|date=27 November 2012 |title=Hawaiian False Killer Whale Endangered|first=Rebekah |last=Kearn | publisher=Courthouse News|access-date=27 November 2012}}

{{Portal|Cetaceans|Mammals|Marine life}}

• List of cetaceans

{{Reflist}}

{{Commons category|Pseudorca crassidens|false killer whales}}

• [http://www.wdcs.org Whale and Dolphin Conservation Society]
• [http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/falsekillerwhale.htm NOAA Fisheries Office of Protected Resources, False Killer Whale (Pseudorca crassidens)]
• [http://www.ascobans.org/ Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas]
• [http://www.accobams.org/ Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area]
• [http://www.cms.int/species/waam/index.htm Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia]
• [http://www.pacificcetaceans.org/ Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region]
• [http://cetus.ucsd.edu/voicesinthesea_org/species/dolphins/falseKiller.html Voices in the Sea - Sounds of the False Killer Whale] {{Webarchive|url=https://web.archive.org/web/20140709235815/http://cetus.ucsd.edu/voicesinthesea_org/species/dolphins/falseKiller.html |date=9 July 2014 }}

{{Cetacea|O.}}

{{Taxonbar|from=Q208132}}

Category:Globicephalinae

Category:Cosmopolitan mammals

Category:Fauna of the Pantropical realm

false killer whale

Category:ESA endangered species

Category:Taxa named by Richard Owen