toothed whale

{{Further information|List of cetaceans|List of extinct cetaceans}}

{{See also|Cryptid whale|Whale#In myth, literature and art}}

{{Quote box|width=30%|align=left|quote=The tube in the head, through which this kind fish takes its breath and spitting water, located in front of the brain and ends outwardly in a simple hole, but inside it is divided by a downward bony septum, as if it were two nostrils; but underneath it opens up again in the mouth in a void.|source=–John Ray, 1671, the earliest description of cetacean airways}}

File:Trolual (Gessner).jpg, 1587, in his Historiae animalium]]

In Aristotle's time, the fourth century BC, whales were regarded as fish due to their superficial similarity. Aristotle, however, could already see many physiological and anatomical similarities with the terrestrial vertebrates, such as blood (circulation), lungs, uterus, and fin anatomy.{{Citation needed|date=December 2019|reason=removed citation to predatory publisher content}} His detailed descriptions were assimilated by the Romans, but mixed with a more accurate knowledge of the dolphins, as mentioned by Pliny the Elder in his Natural history. In the art of this and subsequent periods, dolphins are portrayed with a high-arched head (typical of porpoises) and a long snout. The harbor porpoise is one of the most accessible species for early cetologists, because it could be seen very close to land, inhabiting shallow coastal areas of Europe. Many of the findings that apply to all cetaceans were therefore first discovered in the porpoises.{{cite book|author= Conrad Gesner|url=http://etext.lib.virginia.edu/toc/modeng/public/AriHian.html|title=Historiae animalium |date=6 September 2008 |archive-url= https://web.archive.org/web/20080906090248/http://etext.lib.virginia.edu/toc/modeng/public/AriHian.html |archive-date=6 September 2008 |access-date=4 September 2015}} One of the first anatomical descriptions of the airways of the whales on the basis of a harbor porpoise dates from 1671 by John Ray. It nevertheless referred to the porpoise as a fish.{{cite journal|author=J. Ray|title=An account of the dissection of a porpess|journal=Philosophical Transactions of the Royal Society of London|volume=6|issue=69–80|year=1671|pages=2274–2279|bibcode = 1671RSPT....6.2274R|doi=10.1098/rstl.1671.0048|doi-access=free}}{{cite journal|author=Susanne Prahl|title=Studies for the construction of epicranialen airway when porpoise (Phocoena phocoena Linnaeus, 1758)|journal=Dissertation for the Doctoral Degree of the Department of Biology of the Faculty of Mathematics, Computer Science and Natural Sciences at the University of Hamburg|year=2007|page=6}}

File:Squalodon bariensis.jpg

{{further information|Evolution of cetaceans}}

{{Cladogram

|title=Relationship of toothed whale families{{cite journal|author1=John Gatesy|author2=Jonathan H. Geisler|author3=Joseph Chang|author4=Carl Buell|author5=Annalisa Berta|author6=Robert W. Meredith|author7=Mark S. Springer|author8=Michael R. McGowen|url=https://www.montclair.edu/profilepages/media/5008/user/Gatesy_et_al._2012_A_phylogenetic_blueprint_for_a_modern_whale.pdf|title=A phylogenetic blueprint for a modern whale|journal=Molecular Phylogenetics and Evolution|year=2012|access-date=4 September 2015|volume=66|issue=2|pages=479–506|doi=10.1016/j.ympev.2012.10.012|pmid=23103570}}:

{{Clade|style=font-size:85%;line-height:100%;width:580px;

|label1=Toothed whales

|1={{Clade

|1={{Clade

|1=Sperm whales (Physeteridae) 50 px

|2=Dwarf sperm whales (Kogiidae) 50 px

}}

|2={{Clade

|1=South Asian river dolphins (Platanistidae) 50 px

|2={{Clade

|1=Beaked whales (Ziphiidae) 50 px

|2={{Clade

|label1=Inioidea

|1={{Clade

|1=Yangtze river dolphin (Lipotidae) 50 px

|2={{Clade

|1=Pontoporiidae 50 px

|2=Iniidae 50 px

}}

}}

|label2=Delphinoidea

|2={{Clade

|1=Oceanic dolphins (Delphinidae) 50 px

|2={{Clade

|1=Porpoises (Phocoenidae) 50 px

|2=Belugas, narwhals (Monodontidae) 50 px

}} }} }} }} }} }} }} }}

Toothed whales, as well as baleen whales, are descendants of land-dwelling mammals of the artiodactyl order (even-toed ungulates). They are closely related to the hippopotamus, sharing a common ancestor that lived around 54 million years ago (mya).{{cite book |first=Richard |last=Dawkins |author-link=Richard Dawkins |title=The Ancestor's Tale, A Pilgrimage to the Dawn of Life |publisher=Houghton Mifflin |year=2004 |isbn=978-0-618-00583-3|url={{Google books|plainurl=yes|id=rR9XPnaqvCMC|page=200}}}}

The primitive cetaceans, or archaeocetes, first took to the sea approximately 49 mya and became fully aquatic by 5–10 million years later.{{cite journal |last=Thewissen |first=J. G. M. |author2=Williams, E. M. |title=The Early Radiations of Cetacea (Mammalia): Evolutionary Pattern and Developmental Correlations |journal=Annual Review of Ecology and Systematics |date=1 November 2002 |volume=33 |issue=1 |pages=73–90 |doi=10.1146/annurev.ecolsys.33.020602.095426}} The ancestors of toothed whales and baleen whales diverged in the early Oligocene. This was due to a change in the climate of the southern oceans that affected the environment of the plankton that these whales ate.{{Cite journal|last=Fordyce|first=Ewan|date=January 7, 1980|title=Whale Evolution and Oligocene Southern Ocean Environments|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=31|pages=319–336|doi=10.1016/0031-0182(80)90024-3|bibcode=1980PPP....31..319F|doi-access=free}}

The adaptation of echolocation and enhanced fat synthesis in blubber occurred when toothed whales split apart from baleen whales, and distinguishes modern toothed whales from fully aquatic archaeocetes. This happened around 34 mya.{{cite web|url=https://www.pbs.org/wnet/nature/ocean-giants-going-aquatic-cetacean-evolution/7577/|title=Going Aquatic: Cetacean Evolution|author=Nature|work=PBS |date=2012-03-21}} Unlike toothed whales, baleen whales do not have wax ester deposits nor branched fatty chain acids in their blubber. Thus, more recent evolution of these complex blubber traits occurred after baleen whales and toothed whales split, and only in the toothed whale lineage.{{Cite journal|last=Koopman|first=Heather N.|date=2018-03-07|title=Function and evolution of specialized endogenous lipids in toothed whales|journal=The Journal of Experimental Biology|volume=221|issue=Suppl 1|pages=jeb161471|doi=10.1242/jeb.161471|pmid=29514890|issn=0022-0949|doi-access=free}}{{cite journal|author1=Alexander J. P. Houben|author2=Peter K. Bijl|author3=Jörg Pross|author4=Steven M. Bohaty|author5=Sandra Passchier|author6=Catherine E. Stickley|author7=Ursula Röhl|author8=Saiko Sugisaki|author9=Lisa Tauxe|author10=Tina van de Flierdt|author11=Matthew Olney|author12=Francesca Sangiorgi|author13=Appy Sluijs|author14=Carlota Escutia|author15=Henk Brinkhuis|date=19 April 2013|title=Reorganization of Southern Ocean Plankton Ecosystem at the Onset of Antarctic Glaciation|journal=Science|volume=340|issue=6130|pages=341–344|doi=10.1126/science.1223646|pmid=23599491|bibcode=2013Sci...340..341H|hdl=1874/385683|s2cid=30549019|hdl-access=free}}{{cite journal|author1=Mette E. Steeman|author2=Martin B. Hebsgaard|author3=R. Ewan Fordyce|author4=Simon Y. W. Ho|author5=Daniel L. Rabosky|author6=Rasmus Nielsen|author7=Carsten Rahbek|author8=Henrik Glenner|author9=Martin V. Sørensen|author10=Eske Willerslev|date=24 August 2009|title=Radiation of Extant Cetaceans Driven by Restructuring of the Oceans|journal=Systematic Biology|volume=58|issue=6|pages=573–585|doi=10.1093/sysbio/syp060|pmid=20525610|pmc=2777972}}

Modern toothed whales do not rely on their sense of sight, but rather on their sonar to hunt prey. Echolocation also allowed toothed whales to dive deeper in search of food, with light no longer necessary for navigation, which opened up new food sources.{{cite journal|journal=Nature|title=Eocene evolution of whale hearing|date=7 June 2004|volume=430|issue=7001|doi=10.1038/nature02720|pages=776–778|pmid=15306808 | last1 = Nummela | first1 = S | last2 = Thewissen | first2 = JG | last3 = Bajpai | first3 = S | last4 = Hussain | first4 = ST | last5 = Kumar | first5 = K|bibcode=2004Natur.430..776N|s2cid=4372872}}{{cite journal|url=http://www.saddleback.edu/faculty/thuntley/papers/fordyce_barnes_1994.pdf|title=The Evolutionary History of Whales and Dolphins|first1=R. Ewan |last1=Fordyce|first2=Lawrence G. |last2=Barnes |journal=Ann. Rev. Earth Planet. Sci. |volume=22 |pages=419–455 |date=May 1994 |archive-url=https://web.archive.org/web/20110720042245/http://www.saddleback.edu/faculty/thuntley/papers/fordyce_barnes_1994.pdf|archive-date=20 July 2011 |doi=10.1146/annurev.ea.22.050194.002223}} Toothed whales (Odontocetes) echolocate by creating a series of clicks emitted at various frequencies. Sound pulses are emitted through the melon-shaped forehead, reflected off objects, and retrieved through the lower jaw. Skulls of Squalodon show evidence for the first hypothesized appearance of echolocation.{{cite journal|last1=Whitmore|first1=F.C. Jr.|last2=Sanders|first2=A.E.|year=1976|title=Review of the Oligocene Cetacea|journal=Systematic Zoology|volume=25|issue=4|pages=304–320|doi=10.2307/2412507|jstor=2412507|url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1246&context=usgsstaffpub}} Squalodon lived from the early to middle Oligocene to the middle Miocene, around 33-14 mya. Squalodon featured several commonalities with modern Odontocetes. The cranium was well compressed, the rostrum telescoped outward (a characteristic of the modern parvorder Odontoceti), giving Squalodon an appearance similar to that of modern toothed whales. However, it is thought unlikely that squalodontids are direct ancestors of living dolphins.{{cite web|last=Fordyce|first=R Ewan|title=Shark-toothed dolphins (Family Squalodontidae)|publisher=University of Otago, Department of Geology|url= http://www.otago.ac.nz/geology/research/paleontology/squalodontidae.html|access-date= 10 January 2016}}

File:Dolphin Anatomy.svg]]

File:Sperm whale skeleton labelled.jpg skeleton]]

Toothed whales have torpedo-shaped bodies with usually inflexible necks, limbs modified into flippers, no outer ears, a large tail fin, and bulbous heads (with the exception of the sperm whale family). Their skulls have small eye orbits, long beaks (with the exception sperm whales), and eyes placed on the sides of their heads. Toothed whales range in size from the {{convert|4.5|ft|m|abbr=on}} and {{convert|120|lbs|kg|abbr=on}} vaquita to the {{convert|20|m|ft|adj=on|abbr=on}} and {{convert|55|MT|ST|adj=on|abbr=on}} sperm whale. Overall, they tend to be dwarfed by their relatives, the baleen whales (Mysticeti). Several species have sexual dimorphism, with the females being larger than the males. One exception is with the sperm whale, which has males larger than the females.{{cite journal|last1=Reidenberg |first1=Joy S. |title=Anatomical adaptations of aquatic mammals |journal=The Anatomical Record |date=2007 |volume= 290 |issue=6 |pages=507–513 |doi=10.1002/ar.20541 |pmid=17516440|s2cid=42133705 |doi-access=free }}{{cite book |chapter-url=http://www.cetus.ucsd.edu/SIO133/PDF/Sexual%20Dimorphism.pdf |title=Encyclopedia of Marine Mammals |chapter=Sexual Dimorphism |last1=Ralls |first1=Katherine |last2=Mesnick |first2=Sarah |pages=1005–1011 |edition=2nd |publisher=Academic Press |location=San Diego |isbn=978-0-08-091993-5 |date=2009-02-26 |access-date=2015-11-25 |archive-date=2019-07-25 |archive-url=https://web.archive.org/web/20190725004132/http://www.cetus.ucsd.edu/SIO133/PDF/Sexual%20Dimorphism.pdf |url-status=dead }}

Odontocetes possess teeth with cementum cells overlying dentine cells. Unlike human teeth, which are composed mostly of enamel on the portion of the tooth outside of the gum, whale teeth have cementum outside the gum. Only in larger whales, where the cementum is worn away on the tip of the tooth, does enamel show. There is only a single set of functional teeth (monophyodont dentition).{{Cite journal |last1=Loch |first1=Carolina |last2=Kieser |first2=Jules A. |last3=Fordyce |first3=R. Ewan |date=2015 |title=Enamel ultrastructure in fossil cetaceans (Cetacea: Archaeoceti and Odontoceti) |journal=PLOS ONE |volume=10 |issue=1 |pages=e0116557 |doi=10.1371/journal.pone.0116557 |doi-access=free |pmc=4309603 |pmid=25629995|bibcode=2015PLoSO..1016557L }} Except for the sperm whale, most toothed whales are smaller than the baleen whales. The teeth differ considerably among the species. They may be numerous, with some dolphins bearing over 100 teeth in their jaws. At the other extreme are the narwhals with their single long tusks and the almost toothless beaked whales with tusk-like teeth only in males.{{Cite journal| last1 = Dalebout | first1 = Merel L.| last2 = Steel | first2 = Debbie| last3 = Baker | first3 = C. Scott| title = Phylogeny of the Beaked Whale Genus Mesoplodon (Ziphiidae: Cetacea) Revealed by Nuclear Introns: Implications for the Evolution of Male Tusks| year = 2008 | journal = Systematic Biology | volume = 57 | issue = 6 | pages = 857–875| doi = 10.1080/10635150802559257 | pmid = 19085329 | doi-access = free }} In most beaked whales the teeth are seen to erupt in the lower jaw, and primarily occurs at the males sexual maturity.{{Citation |last=Mesnick |first=Sarah |title=Sexual Dimorphism |date=2018 |work=Encyclopedia of Marine Mammals |edition=3rd |pages=848–853 |editor-last=Würsig |editor-first=Bernd |url=https://linkinghub.elsevier.com/retrieve/pii/B9780128043271002260 |access-date=2024-11-14 |publisher=Academic Press |doi=10.1016/b978-0-12-804327-1.00226-0 |isbn=978-0-12-804327-1 |last2=Ralls |first2=Katherine |editor2-last=Thewissen |editor2-first=J. G. M. |editor3-last=Kovacs |editor3-first=Kit M.}} Not all species are believed to use their teeth for feeding. For instance, the sperm whale likely uses its teeth for aggression and showmanship.

Breathing involves expelling stale air from their one blowhole, forming an upward, steamy spout, followed by inhaling fresh air into the lungs. Spout shapes differ among species, which facilitates identification. The spout only forms when warm air from the lungs meets cold air, so it does not form in warmer climates, as with river dolphins.{{cite web |url=http://www.afsc.noaa.gov/nmml/education/cetaceans/baleen1.php |title=Baleen |work=NOAA Fisheries |publisher= United States Department of Commerce |access-date=29 August 2015}}{{cite journal |last1=Scholander |first1=Per Fredrik |title=Experimental investigations on the respiratory function in diving mammals and birds |year=1940 |journal=Hvalraadets Skrifter |volume=22 |pages=1–131}}

Almost all cetaceans have a thick layer of blubber, except for river dolphins. In species that live near the poles, the blubber can be as thick as {{convert|11|in|cm|abbr=on}}. This blubber can help with buoyancy, protection to some extent as predators would have a hard time getting through a thick layer of fat, energy for fasting during leaner times, and insulation from the harsh climate. Calves are born with only a thin layer of blubber, but some species compensate for this with thick lanugos.

Toothed whales have also evolved the ability to store large amounts of wax esters in their adipose tissue as an addition to or in complete replacement of other fats in their blubber. They can produce isovaleric acid from branched chain fatty acids (BCFA). These adaptations are unique, are only in more recent, derived lineages and were likely part of the transition for species to become deeper divers as the families of toothed whales (Physeteridae, Kogiidae, and Ziphiidae) that have the highest quantities of wax esters and BCFAs in their blubber are also the species that dive the deepest and for the longest amount of time.

Toothed whales have a two-chambered stomach similar in structure to terrestrial carnivores. They have fundic and pyloric chambers.{{cite book |url={{google books|plainurl=y|id=DZuAsci2apAC |page=11}}| author1=Stevens, C. Edward |author2=Hume, Ian D. |title=Comparative Physiology of the Vertebrate Digestive System |publisher=Cambridge University Press |isbn=978-0-521-44418-7|page=317 |year=1995}}

File:Living-on-the-Edge-Settlement-Patterns-by-the-Symbiotic-Barnacle-Xenobalanus-globicipitis-on-Small-pone.0127367.s001.ogv pod swimming]]

Cetaceans have two flippers on the front, and a tail fin. These flippers contain four digits. Although toothed whales do not possess fully developed hind limbs, some, such as the sperm whale, possess discrete rudimentary appendages, which may contain feet and digits.{{cn|date=February 2021}} Toothed whales are fast swimmers in comparison to seals, which typically cruise at 5–15 knots, or {{convert|9|–|28|kph|mph|abbr=on}}; the sperm whale, in comparison, can travel at speeds of up to {{convert|35|kph|mph|abbr=on}}. The fusing of the neck vertebrae, while increasing stability when swimming at high speeds, decreases flexibility, rendering them incapable of turning their heads; river dolphins, however, have unfused neck vertebrae and can turn their heads. When swimming, toothed whales rely on their tail fins to propel them through the water. Flipper movement is continuous. They swim by moving their tail fin and lower body up and down, propelling themselves through vertical movement, while their flippers are mainly used for steering. Some species log out of the water, which may allow them to travel faster.{{Explain|date=February 2021}} Their skeletal anatomy allows them to be fast swimmers. Most species have a dorsal fin.{{cite book |last1=Klinowska |first1=Margaret |last2=Cooke |first2=Justin |year=1991 |title=Dolphins, Porpoises, and Whales of the World: the IUCN Red Data Book |publisher=IUCN Publications |location=Columbia University Press, NY |url=https://portals.iucn.org/library/sites/library/files/documents/RD-1991-001.pdf|isbn=978-2-88032-936-5}}

Most toothed whales are adapted for diving to great depths, porpoises are one exception. In addition to their streamlined bodies, they can slow their heart rate to conserve oxygen; blood is rerouted from tissue tolerant of water pressure to the heart and brain among other organs; haemoglobin and myoglobin store oxygen in body tissue; and they have twice the concentration of myoglobin than haemoglobin. Before going on long dives, many toothed whales exhibit a behaviour known as sounding; they stay close to the surface for a series of short, shallow dives while building their oxygen reserves, and then make a sounding dive.{{cite journal |last1=Norena |first1=S. R. |last2=Williams |first2=T. M. |title=Body size and skeletal muscle myoglobin of cetaceans: adaptations for maximizing dive duration |journal= Comparative Biochemistry and Physiology A |volume=126 |issue=2 |year=2000 |pages=181–191 |doi=10.1016/S1095-6433(00)00182-3 |pmid=10936758}}

File:Delfinekko.gif by cetaceans]]

Toothed whale eyes are relatively small for their size, yet they do retain a good degree of eyesight. Also, the eyes are on the sides of the head, so their vision consists of two fields, rather than a binocular view as humans have. When a beluga surfaces, its lenses and corneas correct the nearsightedness that results from the refraction of light; they contain both rod and cone cells, meaning they can see in both dim and bright light. They do, however, lack short wavelength-sensitive visual pigments in their cone cells, indicating a more limited capacity for colour vision than most mammals.{{cite journal |author1=Mass, Alla M. |author2=Supin, Alexander |author3=Y. A. |title=Adaptive features of aquatic mammals' eyes |journal=Anatomical Record |volume=290 |issue=6 |pages=701–715 |date=21 May 2007 |doi=10.1002/ar.20529 |pmid=17516421|s2cid=39925190 |doi-access=free }} Most toothed whales have slightly flattened eyeballs, enlarged pupils (which shrink as they surface to prevent damage), slightly flattened corneas, and a tapetum lucidum; these adaptations allow for large amounts of light to pass through the eye, and, therefore, a very clear image of the surrounding area. In water, a whale can see around {{convert|10.7|m|ft|abbr=on}} ahead of itself, but they have a smaller range above water. They also have glands on the eyelids and outer corneal layer that act as protection for the cornea.{{rp|505–519}}

The olfactory lobes are absent in toothed whales, and unlike baleen whales, they lack the vomeronasal organ, suggesting they have no sense of smell.{{rp|481–505}}

Toothed whales are not thought to have a good sense of taste, as their taste buds are atrophied or missing altogether. However, some dolphins have preferences between different kinds of fish, indicating some sort of attachment to taste.{{rp|447–455}}

{{Main |Animal echolocation#Toothed whales}}

File:Toothed whale sound production.svg

Toothed whales are capable of making a broad range of sounds using nasal airsacs located just below the blowhole.{{cite web |last=Viegas |first=Jennifer |title=Dolphins Talk Like Humans |work=Discovery News |year=2011 |url=http://news.discovery.com/animals/dolphin-talk-communication-humans-110906.html |access-date=September 19, 2011 |archive-date=September 24, 2011 |archive-url=https://web.archive.org/web/20110924060555/http://news.discovery.com/animals/dolphin-talk-communication-humans-110906.html |url-status=dead }} Clicks are directional and are used for echolocation, often occurring in a short series called a click train. The click rate increases when approaching an object of interest. Toothed whale biosonar clicks are amongst the loudest sounds made by marine animals.{{Cite book

|title= The Sonar of Dolphins

|last1= Au |first1=W. W. L.

|publisher=Springer

|location=New York

|year=1993

|isbn= 978-3-540-97835-0}}

The cetacean ear has specific adaptations to the marine environment. In humans, the middle ear works as an impedance equalizer between the outside air's low impedance and the cochlear fluid's high impedance. In whales, and other marine mammals, no great difference exists between the outer and inner environments. Instead of sound passing through the outer ear to the middle ear, whales receive sound through the throat, from which it passes through a low-impedance, fat-filled cavity to the inner ear.{{cite journal |last1=Cranford |first1=T.W. |last2=Krysl |first2=P. |last3=Hildebrand |first3=J.A. |title=Acoustic pathways revealed: simulated sound transmission and reception in Cuvier's beaked whale (Ziphius cavirostris) |journal=Bioinspiration & Biomimetics |date=2008 |volume=3 |issue=1 |pages=016001 |doi=10.1088/1748-3182/3/1/016001 |pmid=18364560 |bibcode=2008BiBi....3a6001C |s2cid=26098966 }} The ear is acoustically isolated from the skull by air-filled sinus pockets, which allow for greater directional hearing underwater.{{cite journal |author=Nummela, Sirpa |title=Sound transmission in archaic and modern whales: Anatomical adaptations for underwater hearing |journal=The Anatomical Record |volume=290 |issue=6 |pages=716–733 |year=2007 |doi=10.1002/ar.20528 |last2=Thewissen |first2=J.G.M |last3=Bajpai |first3=Sunil |last4=Hussain |first4=Taseer |last5=Kumar |first5=Kishor |pmid=17516434 |s2cid=12140889 |doi-access=free }}

Odontocetes generate sounds independently of respiration using recycled air that passes through air sacs and phonic (alternatively monkey) lips. Integral to the lips are oil-filled organs called dorsal bursae that have been suggested to be homologous in the dolphin to the sperm whale's spermaceti organ.{{cite journal |last1=Cranford |first1=Ted W. |last2=Amundin |first2=Mats |last3=Norris |first3=Kenneth S. |date=1996 |title=Functional morphology and homology in the odontocete nasal complex: Implications for sound generation |journal=Journal of Morphology |volume=228 |issue=3 |pages=223–285 |doi=10.1002/(SICI)1097-4687(199606)228:3<223::AID-JMOR1>3.0.CO;2-3 |pmid=8622183 |issn=0362-2525}} These send out high-frequency clicks through the sound-modifying organs of the extramandibular fat body, intramandibular fat body and the melon.

The melon consists of fat, and the skull of any such creature containing a melon will have a large depression. The melon size varies between species, the bigger it is, the more dependent they are on it. A beaked whale, for example, has a small bulge sitting on top of its skull, whereas a sperm whale's head is filled mainly with the melon.{{cite book |last1=Thomas |first1=Jeanette A. |last2=Kastelein |first2=Ronald A. |title=Sensory Abilities of Cetaceans: Laboratory and Field Evidence |isbn=978-1-4899-0860-5 |doi=10.1007/978-1-4899-0858-2 |date=1990 |url={{google books |plainurl=y |id=VWz1BwAAQBAJ |page=1}} |volume=196 |publisher= Springer Science & Business Media |location=New York |s2cid=32801659 }}{{rp |1–19}}{{cite book |last1=Thewissen |first1=J. G. M. |last2=Perrin |first2=William R. |last3=Wirsig |first3=Bernd |chapter=Hearing |pages=[https://archive.org/details/encyclopediaofma2002unse/page/570 570–572] |title=Encyclopedia of Marine Mammals |year=2002 |publisher=Academic Press |location=San Diego |isbn=978-0-12-551340-1 |chapter-url=https://archive.org/details/encyclopediaofma2002unse/page/570 }}{{cite book |last1=Ketten |first1=Darlene R. |chapter=The Marine Mammal Ear: Specializations for Aquatic Audition and Echolocation |title=The Evolutionary Biology of Hearing |editor1-last=Webster |editor1-first=Douglas B. |editor2-last=Fay |editor2-first=Richard R. |editor3-last=Popper |editor3-first=Arthur N. |year=1992 |publisher=Springer–Verlag |chapter-url=https://www.researchgate.net/publication/230691464 |doi=10.1007/978-1-4612-2784-7_44 |isbn=978-1-4612-7668-5 |pages=717–750}} Directional asymmetry in the skull has been seen amongst many generations, used for echolocation. This asymmetry is useful in focusing the use of bio sonar effectively when deep diving for prey. {{Cite journal |last=Vicari |first=Deborah |last2=McGowen |first2=Michael R. |last3=Lambert |first3=Olivier |last4=Brown |first4=Richard P. |last5=Bianucci |first5=Giovanni |last6=Sabin |first6=Richard C. |last7=Meloro |first7=Carlo |date=2023-06-01 |title=Ecomorphology of toothed whales (Cetacea, Odontoceti) as revealed by 3D skull geometry |url=https://link.springer.com/article/10.1007/s10914-022-09642-4 |journal=Journal of Mammalian Evolution |language=en |volume=30 |issue=2 |pages=475–491 |doi=10.1007/s10914-022-09642-4 |issn=1573-7055|doi-access=free }} Odontocetes are well adapted to hear sounds at ultrasonic frequencies, as opposed to mysticetes who generally hear sounds within the range of infrasonic frequencies.{{cite journal |last1=Viglino |first1=M. |last2=Gaetán |first2=M. |last3=Buono |first3=M.R. |last4=Fordyce |first4=R.E. |last5=Park |first5=T. |title=Hearing from the ocean and into the river: the evolution of the inner ear of Platanistoidea (Cetacea: Odontoceti) |journal=Paleobiology |date=2021 |volume=47 |issue=4 |pages=591–611 |doi=10.1017/pab.2021.11 |bibcode=2021Pbio...47..591V |s2cid=233517623 |url=https://zenodo.org/record/4480277 }}

Bottlenose dolphins have been found to have signature whistles unique to each individual. Dolphins use these whistles to communicate with one another by identifying an individual. It can be seen as the dolphin equivalent of a name for humans.{{cite news |url=https://www.bbc.co.uk/news/science-environment-23410137 |title=Dolphins 'call each other by name' |date=July 22, 2013 |work=BBC News}}

Because dolphins generally live in groups, communication is necessary. Signal masking is when other similar sounds (conspecific sounds) interfere with the original sound.{{cite journal |last=Quick |first=Nicola |author2=Vincent Janik |title=Whistle Rates of Wild Bottlenose Dolphins (Tursiops truncatus): Influences of Group Size and Behavior |journal=Journal of Comparative Psychology |date=2008 |volume=122 |issue=3 |pages=305–311 |doi=10.1037/0735-7036.122.3.305 |pmid=18729659}} In larger groups, individual whistle sounds are less prominent. Dolphins tend to travel in pods, sometimes of up to 600 members. {{cite journal |last1=Bouveroux |first1=Thibaut N. |last2=Caputo |first2=Michelle |last3=Froneman |first3=Pierre W. |last4=Plön |first4=Stephanie |title=Largest reported groups for the Indo-Pacific bottlenose dolphin (Tursiops aduncus) found in Algoa Bay, South Africa: Trends and potential drivers |journal=Marine Mammal Science |volume=34 |issue=3 |year=2018 |pages=645–665 |issn=0824-0469 |doi=10.1111/mms.12471|bibcode=2018MMamS..34..645B }}

{{Main|Cetacean intelligence}}

{{See also|Cetacean surfacing behaviour}}

File:PacificWhiteSidedDolphine.jpgs porpoising]]

Cetaceans are known to communicate and therefore are able to teach, learn, cooperate, scheme, and grieve.{{cite news |last=Siebert |first=Charles |title=Watching Whales Watching Us |work=New York Times Magazine |date=8 July 2009|access-date=29 August 2015 |url=https://www.nytimes.com/2009/07/12/magazine/12whales-t.html?pagewanted=all}} The neocortex of many species of dolphins is home to elongated spindle neurons that, prior to 2007, were known only in hominids.{{cite journal |author=Watson, K.K. |title=Dendritic architecture of the Von Economo neurons |journal=Neuroscience |volume=141 |issue=3 |pages=1107–1112 |year=2006 |doi=10.1016/j.neuroscience.2006.04.084 |last2=Jones |first2=T. K. |last3=Allman |first3=J. M. |pmid=16797136|s2cid=7745280 }} In humans, these cells are involved in social conduct, emotions, judgement, and theory of mind. Dolphin spindle neurons are found in areas of the brain homologous to where they are found in humans, suggesting they perform a similar function.

Brain size was previously considered a major indicator of the intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks.{{Cite journal |last=Marino |first=Lori |last2=McShea |first2=Daniel W. |last3=Uhen |first3=Mark D. |date=2004-10-20 |title=Origin and evolution of large brains in toothed whales |url=http://dx.doi.org/10.1002/ar.a.20128 |journal=The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology |volume=281A |issue=2 |pages=1247–1255 |doi=10.1002/ar.a.20128 |issn=1552-4884}} Allometric analysis indicates that mammalian brain size scales around the two-thirds or three-quarters exponent of the body mass. Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an encephalization quotient that can be used as another indication of animal intelligence. Sperm whales have the largest brain mass of any animal on earth, averaging {{convert|8,000|cm3|in3|abbr=on}} and {{convert|7.8|kg|lbs|abbr=on}} in mature males, in comparison to the average human brain which averages {{convert|1450|cm3|in3|abbr=on}} in mature males.{{cite web | url=http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/spermwhale.htm |title=Sperm Whales brain size| publisher=NOAA Fisheries – Office of Protected Resources |access-date=9 August 2015}} The brain to body mass ratio in some odontocetes, such as belugas and narwhals, is second only to humans.{{cite web |url=http://blogs.scientificamerican.com/news-blog/are-whales-smarter-than-we-are/ |author=Fields, R. Douglas |title=Are whales smarter than we are? | publisher=Scientific American |access-date=9 August 2015}}

File:The-Ecological-Conditions-That-Favor-Tool-Use-and-Innovation-in-Wild-Bottlenose-Dolphins-(Tursiops-pone.0022243.s002.ogv attached along the substrate to simulate the sponging behavior by dolphins]]

Dolphins are known to engage in complex play behaviour, which includes such things as producing stable underwater toroidal air-core vortex rings or "bubble rings". Two main methods of bubble ring production are: rapid puffing of a burst of air into the water and allowing it to rise to the surface, forming a ring, or swimming repeatedly in a circle and then stopping to inject air into the helical vortex currents thus formed. They also appear to enjoy biting the vortex rings, so that they burst into many separate bubbles and then rise quickly to the surface. Dolphins are known to use this method during hunting.{{cite book|last1=Grandin|first1=Temple|last2=Johnson|first2=Catherine|year=2009|title=Animals Make Us Human: Creating the Best Life for Animals|chapter=Wildlife|page=[https://archive.org/details/animalsmakeushum00gran/page/240 240]|publisher=Houghton Mifflin Harcourt |isbn=978-0-15-101489-7|chapter-url-access=registration|chapter-url=https://archive.org/details/animalsmakeushum00gran|url=https://archive.org/details/animalsmakeushum00gran/page/240}} Dolphins are also known to use tools. In Shark Bay, a population of Indo-Pacific bottlenose dolphins put sponges on their beak to protect them from abrasions and sting ray barbs while foraging in the seafloor.{{cite journal| first1=Rachel|last1=Smolker|first2=Andrew|last2=Richards|first3=Richard|last3=Connor|first4=Janet|last4=Mann|first5=Per|last5=Berggren|year=1997|title=Sponge Carrying by Dolphins (Delphinidae, Tursiops sp.): A Foraging Specialization Involving Tool Use?|journal=Ethology|volume=103|issue=6|pages=454–465|doi=10.1111/j.1439-0310.1997.tb00160.x|bibcode=1997Ethol.103..454S |hdl=2027.42/71936|url=https://deepblue.lib.umich.edu/bitstream/2027.42/71936/1/j.1439-0310.1997.tb00160.x.pdf|hdl-access=free}} This behaviour is passed on from mother to daughter, and it is only observed in 54 female individuals.{{cite journal|first1=Eric M.|last1=Patterson|first2=Janet|last2=Mann|year=2011|title=The Ecological Conditions That Favor Tool Use and Innovation in Wild Bottlenose Dolphins (Tursiops sp.)|journal=PLOS ONE|volume=6|issue=8|doi=10.1371/journal.pone.0022243|pages=e22243|pmid=21799801|pmc=3140497|bibcode=2011PLoSO...622243P|doi-access=free}}

Self-awareness is seen, by some, to be a sign of highly developed, abstract thinking. Self-awareness, though not well-defined scientifically, is believed to be the precursor to more advanced processes like metacognitive reasoning (thinking about thinking) that are typical of humans. Research in this field has suggested that cetaceans, among others,{{cite web | url=http://www.livescience.com/4272-elephant-awareness-mirrors-humans.html |author=Charles Q. Choi| title=Elephant Self-Awareness Mirrors Humans |publisher=Live Science |date=30 October 2006 |access-date=29 August 2015}} possess self-awareness. The most widely used test for self-awareness in animals is the mirror test, in which a temporary dye is placed on an animal's body, and the animal is then presented with a mirror; then whether the animal shows signs of self-recognition is determined.{{cite news |url=https://www.nytimes.com/2001/05/01/science/brainy-dolphins-pass-the-human-mirror-test.html |title=Brainy Dolphins Pass the Human 'Mirror' Test|last=Derr|first=Mark |newspaper=New York Times |year=2001|access-date=3 August 2015}} In 1995, Marten and Psarakos used television to test dolphin self-awareness.{{cite journal|last1=Marten|first1=Ken|last2=Psarakos|first2=Suchi|title=Using Self-View Television to Distinguish between Self-Examination and Social Behavior in the Bottlenose Dolphin (Tursiops truncatus)|journal=Consciousness and Cognition|volume=4|pages=205–224|number=2|date=June 1995|doi=10.1006/ccog.1995.1026|pmid=8521259|s2cid=44372881}} They showed dolphins real-time footage of themselves, recorded footage, and another dolphin. They concluded that their evidence suggested self-awareness rather than social behavior. While this particular study has not been repeated since then, dolphins have since "passed" the mirror test.

{{Clear}}

{{See also|Whale song#Odontocete whales}}

File:Dolphin1.jpg of dolphin vocalizations. Whistles, whines, and clicks are visible as upside down V's, horizontal striations, and vertical lines, respectively.]]

Dolphins make a broad range of sounds using nasal airsacs located just below the blowhole. Roughly three categories of sounds can be identified: frequency modulated whistles, burst-pulsed sounds and clicks. Dolphins communicate with whistle-like sounds produced by vibrating connective tissue, similar to the way human vocal cords function, and through burst-pulsed sounds, though the nature and extent of that ability is not known. The clicks are directional and are for echolocation, often occurring in a short series called a click train. The click rate increases when approaching an object of interest. Dolphin echolocation clicks are amongst the loudest sounds made by marine animals.{{Cite book|title= The Sonar of Dolphins|last1= Au |first1=W. W. L.|publisher=Springer|location=New York|year=1993|isbn= 978-3-540-97835-0}}

Bottlenose dolphins have been found to have signature whistles, a whistle that is unique to a specific individual. These whistles are used in order for dolphins to communicate with one another by identifying an individual. It can be seen as the dolphin equivalent of a name for humans. These signature whistles are developed during a dolphin's first year; it continues to maintain the same sound throughout its lifetime.{{cite journal|last=Janik|first=Vincent|author2=Laela Sayigh|title=Communication in bottlenose dolphins: 50 years of signature whistle research|journal=Journal of Comparative Physiology|date=7 May 2013|volume=199|issue=6|pages=479–489|doi=10.1007/s00359-013-0817-7|pmid=23649908|s2cid=15378374}} An auditory experience influences the whistle development of each dolphin. Dolphins are able to communicate to one another by addressing another dolphin through mimicking their whistle. The signature whistle of a male bottlenose dolphin tends to be similar to that of his mother, while the signature whistle of a female bottlenose dolphin tends to be more identifying.{{cite web |url=http://www.whoi.edu/science/B/people/kamaral/marinemammalacoustics.html |title=Marine Mammal vocalizations: language or behavior? |date=August 24, 2013}} Bottlenose dolphins have a strong memory when it comes to these signature whistles, as they are able to relate to a signature whistle of an individual they have not encountered for over twenty years.{{cite web |url=http://news.uchicago.edu/article/2013/08/06/dolphins-keep-lifelong-social-memories-longest-non-human-species |title=Dolphins keep lifelong social memories, longest in a non-human species |date=August 24, 2013}} Research done on signature whistle usage by other dolphin species is relatively limited. The research on other species done so far has yielded varied outcomes and inconclusive results.Emily T. Griffiths (2009). "[http://www.seawatchfoundation.org.uk/wp-content/uploads/2012/08/Griffiths2009_SBCDwhistle-repertoire.pdf Whistle repertoire analysis of the short beaked Common Dolphin, Delphinus delphis, from the Celtic Deep and the Eastern and the Eastern Tropical Pacific Ocean]", Master's Thesis, School of Ocean Sciences

Bangor UniversityMelba C. Caldwell et al. – Statistical Evidence for Signature Whistles in the Spotted Dolphin, Stenella plagiodon.Melba C. Caldwell et al. – Statistical Evidence for Signature Whistles in the Pacific Whitesided Dolphin, Lagenorhynchus obliquidens.Rüdiger Riesch et al. – Stability and group specificity of stereotyped whistles in resident killer whales, Orcinus orca, off British Columbia.

Sperm whales can produce three specific vocalisations: creaks, codas, and slow clicks. A creak is a rapid series of high-frequency clicks that sounds somewhat like a creaky door hinge. It is typically used when homing in on prey.{{rp|135}} A coda is a short pattern of 3 to 20 clicks that is used in social situations to identify one another (like a signature whistle), but it is still unknown whether sperm whales possess individually specific coda repertoires or whether individuals make codas at different rates.{{cite journal| last1= Moore |first1= K. E. |first2= W. A. |last2= Watkins |first3= P. L. |last3= Tyack |year= 1993 |title= Pattern similarity in shared codas from sperm whales (Physeter catodon) | journal= Marine Mammal Science |volume= 9 |pages=1–9| doi= 10.1111/j.1748-7692.1993.tb00421.x | issue=1|bibcode= 1993MMamS...9....1M }} Slow clicks are heard only in the presence of males (it is not certain whether females occasionally make them). Males make a lot of slow clicks in breeding grounds (74% of the time), both near the surface and at depth, which suggests they are primarily mating signals. Outside breeding grounds, slow clicks are rarely heard, and usually near the surface.{{rp|144}}

{{See also|Beluga whale#Predation}}

All whales are carnivorous and predatory. Odontocetes, as a whole, mostly feed on fish and cephalopods, and then followed by crustaceans and bivalves. All species are generalist and opportunistic feeders. Some may forage with other kinds of animals, such as other species of whales or certain species of pinnipeds.{{cite book |last=Riedman |first=M. |year=1991 |title=The Pinnipeds: Seals, Sea Lions, and Walruses |url=https://archive.org/details/pinnipedssealsse0000ried |url-access=registration |publisher=University of California Press|page=[https://archive.org/details/pinnipedssealsse0000ried/page/168 168] |isbn=978-0-520-06498-0}} One common feeding method is herding, where a pod squeezes a school of fish into a small volume, known as a bait ball. Individual members then take turns plowing through the ball, feeding on the stunned fish. Coralling is a method where dolphins chase fish into shallow water to catch them more easily.{{cite book |last1=Thewissen |first1=J. G. M. |last2=Perrin |first2=William R. |last3=Wursig |first3=Bernd |chapter=Hearing |pages=[https://archive.org/details/encyclopediaofma2002unse/page/570 570–572] |title=Encyclopedia of Marine Mammals |year=2002 |publisher=Academic Press |location=San Diego |isbn=978-0-12-551340-1 |chapter-url=https://archive.org/details/encyclopediaofma2002unse/page/570 }} Orcas and bottlenose dolphins have also been known to drive their prey onto a beach to feed on it, a behaviour known as beach or strand feeding.{{cite web|title=Coastal Stock(s) of Atlantic Bottlenose Dolphin: Status Review and Management Proceedings and Recommendations from a Workshop held in Beaufort, North Carolina, 13 September 1993 – 14 September 1993|url=http://www.nmfs.noaa.gov/pr/pdfs/species/coastalbottlenosestock.pdf|author=((U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service))|pages=56–57}}Gregory K. Silber, Dagmar Fertl (1995) – Intentional beaching by bottlenose dolphins (Tursiops truncatus) in the Colorado River Delta, Mexico. The shape of the snout may correlate with tooth number and thus feeding mechanisms. The narwhal, with its blunt snout and reduced dentition, relies on suction feeding.{{cite book|author=Berta, A.|author2=Sumich, J. L.|author3=Kovacs, K. M.|year=2015|title=Marine Mammals: Evolutionary Biology|publisher=Academic Press|page=430|isbn=978-0123970022}}

Sperm whales usually dive between {{convert|300|and|800|m|ft}}, and sometimes {{convert|1|to|2|km|ft}}, in search of food.{{cite book|last=Whitehead|first=Hal|year=2003|title=Sperm Whales: Social Evolution in the Ocean|location=Chicago|publisher=University of Chicago Press|isbn=978-0-226-89518-5|url={{Google books|plainurl=yes|id=TKXdCli7nI0C}}}}{{rp|79}} Such dives can last more than an hour.{{rp|79}} They feed on several species, notably the giant squid, but also the colossal squid, octopuses, and fish like demersal rays, but their diet is mainly medium-sized squid.{{rp|43–55}} Some prey may be taken accidentally while eating other items.{{rp|43–55}} A study in the Galápagos found that squid from the genera Histioteuthis (62%), Ancistrocheirus (16%), and Octopoteuthis (7%) weighing between {{convert|12|and|650|g|lb}} were the most commonly taken.{{cite journal|author1=Smith S. |author2=Whitehead, H. |name-list-style=amp |year=2000|title=The Diet of Galapagos sperm whales Physeter macrocephalus as indicated by faecal sample analysis|journal=Marine Mammal Science|volume=16|issue=2|pages=315–325|doi=10.1111/j.1748-7692.2000.tb00927.x|bibcode=2000MMamS..16..315S }} Battles between sperm whales and giant squid or colossal squid have never been observed by humans; however, white scars are believed to be caused by the large squid. A 2010 study suggests that female sperm whales may collaborate when hunting Humboldt squid.{{cite news|title=Sperm Whales Use Teamwork to Hunt Prey|author=Perkins, S.|url=https://www.wired.com/wiredscience/2010/02/sperm-whale-teams/|access-date=2010-02-24|magazine=Wired|date=2010-02-23}}

File:Killer Whale Tipe B.jpg]]

The orca is known to prey on numerous other toothed whale species. One example is the false killer whale.{{cite journal|author=Visser, Ingrid N|year=2010|title=First Record of Predation on False Killer Whales (Pseudorca crassidens) by Killer Whales (Orcinus orca)|journal= Aquatic Mammals|pages=195–204|doi=10.1578/AM.36.2.2010.195|last2=Zaeschmar|first2=Jochen|last3=Halliday|first3=Jo|last4=Abraham|first4=Annie|last5=Ball |first5=Phil|last6=Bradley|first6=Robert|last7=Daly|first7=Shamus |last8=Hatwell|first8=Tommy|last9=Johnson|first9=Tammy|volume=36|issue=2|s2cid=85669121 }} To subdue and kill whales, orcas continually ram them with their heads; this can sometimes kill bowhead whales, or severely injure them. Other times, they corral their prey before striking. They are typically hunted by groups of 10 or fewer orca, but they are seldom attacked by an individual. Calves are more commonly taken by orca, but adults can be targeted, as well.{{cite journal |url=https://www.science.org/content/article/killer-whale-menu-finally-revealed |title=Killer Whale Menu Finally Revealed |author=Morrel, Virginia |journal=Science |date=30 January 2012 |access-date=29 August 2015}} Groups even attack larger cetaceans such as minke whales, gray whales, and rarely sperm whales or blue whales.{{cite journal|doi=10.1111/j.1365-2907.1991.tb00291.x|last1=Jefferson |first1=T. A. |last2=Stacey |first2=P. J. |last3=Baird |first3=R. W.|year=1991|url=http://swfsc.noaa.gov/uploadedFiles/Divisions/PRD/Publications/Jeffersonetal.1991(8).pdf |title=A review of killer whale interactions with other marine mammals: predation to co-existence|journal= Mammal Review|volume=21|pages=151–180|issue=4}}{{cite journal|author1=Ford, J. K. B. |author2=Reeves R. R. |name-list-style=amp |year=2008|title=Fight or flight: antipredator strategies of baleen whales|journal=Mammal Review|volume=38|pages=50–86|doi=10.1111/j.1365-2907.2008.00118.x|issue=1|citeseerx=10.1.1.573.6671 }} Other marine mammal prey species include nearly 20 species of seal, sea lion and fur seal.{{Cite book|last1=Heimlich |first1=Sara |last2=Boran |first2=James|year=2001|title=Killer Whales|location=Stillwater, MN|publisher=Voyageur Press|url=https://books.google.com/books?id=lQ9RUAQgEiIC&pg=PP1|isbn=978-0-89658-545-4}}

These cetaceans are targeted by terrestrial and pagophilic predators. The polar bear is well-adapted for hunting Arctic whales and calves. Bears are known to use sit-and-wait tactics, as well as active stalking and pursuit of prey on ice or water. Whales lessen the chance of predation by gathering in groups. This, however, means less room around the breathing hole as the ice slowly closes the gap. When out at sea, whales dive out of the reach of surface-hunting orca. Polar bear attacks on belugas and narwhals are usually successful in winter, but rarely inflict any damage in summer.{{cite journal |url=http://pubs.aina.ucalgary.ca/arctic/Arctic43-2-99.pdf |last1=Smith|first1= Thomas G.|last2=Sjare|first2=Becky |title=Predation of Belugas and Narwhals by Polar Bears in Nearshore Areas of the Canadian High Arctic |journal=Arctic|volume=43|number=2 |pages=99–102|year=1990 |access-date=29 August 2015 |doi=10.14430/arctic1597}}

For most of the smaller species of dolphins, only a few of the larger sharks, such as the bull shark, dusky shark, tiger shark, and great white shark, are a potential risk, especially for calves.{{cite journal|first=Michael|last=Heithaus|year=2001|title=Predator-prey and competitive interactions between sharks (order Selachii) and dolphins (suborder Odontoceti): a review|journal=Journal of Zoology|volume=253|issue=1|pages=53–68|doi=10.1017/S0952836901000061|citeseerx=10.1.1.404.130}} Dolphins can tolerate and recover from extreme injuries (including shark bites) although the exact methods used to achieve this are not known. The healing process is rapid and even very deep wounds do not cause dolphins to hemorrhage to death. Even gaping wounds restore in such a way that the animal's body shape is restored, and infection of such large wounds are rare.{{cite web |url=http://explore.georgetown.edu/news/?ID=57991&PageTemplateID=295 |title=Dolphins' "Remarkable" Recovery from Injury Offers Important Insights for Human Healing |author=Georgetown University Medical Center |author-link=Georgetown University Medical Center |access-date=July 26, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111205105601/http://explore.georgetown.edu/news/?ID=57991&PageTemplateID=295 |archive-date=December 5, 2011 }}

{{See also|Dolphin#Reproduction and sexuality}}

Toothed whales are fully aquatic creatures, which means their birth and courtship behaviours are very different from terrestrial and semiaquatic creatures. Since they are unable to go onto land to calve, they deliver their young with the fetus positioned for tail-first delivery. This prevents the calf from drowning either upon or during delivery. To feed the newborn, toothed whales, being aquatic, must squirt the milk into the mouth of the calf. Being mammals, they have mammary glands used for nursing calves; they are weaned around 11 months of age. This milk contains high amounts of fat which is meant to hasten the development of blubber; it contains so much fat, it has the consistency of toothpaste.{{cite episode |series=Modern Marvels |title=Milk |season=14 |network=The History Channel |airdate=2008-01-07 |access-date=}} Females deliver a single calf, with gestation lasting about a year, dependency until one to two years, and maturity around seven to 10 years, all varying between the species. This mode of reproduction produces few offspring, but increases the survival probability of each one. Females, referred to as "cows", carry the responsibility of childcare, as males, referred to as "bulls", play no part in raising calves.

In orcas, false killer whales, short-finned pilot whales, narwhals, and belugas, there is an unusually long post-reproductive lifespan (menopause) in females. Older females, though unable to have their own children, play a key role in the rearing of other calves in the pod, and in this sense, given the costs of pregnancy especially at an advanced age, extended menopause is advantageous.{{Cite journal|last1=Ellis|first1=Samuel|last2=Franks|first2=Daniel W.|last3=Nattrass|first3=Stuart|last4=Currie|first4=Thomas E.|last5=Cant|first5=Michael A.|last6=Giles|first6=Deborah|last7=Balcomb|first7=Kenneth C.|last8=Croft|first8=Darren P.|date=2018-08-27|title=Analyses of ovarian activity reveal repeated evolution of post-reproductive lifespans in toothed whales|journal=Scientific Reports|language=en|volume=8|issue=1|page=12833|doi=10.1038/s41598-018-31047-8|issn=2045-2322|doi-access=free|pmid=30150784|pmc=6110730|bibcode=2018NatSR...812833E}}{{Cite journal|last1=Connor|first1=Richard C|last2=Mann|first2=Janet|last3=Tyack|first3=Peter L|last4=Whitehead|first4=Hal|date=1998-06-01|title=Social evolution in toothed whales|journal=Trends in Ecology & Evolution|volume=13|issue=6|pages=228–232|doi=10.1016/S0169-5347(98)01326-3|pmid=21238276|issn=0169-5347|doi-access=free|bibcode=1998TEcoE..13..228C }}

{{Main|Sperm whaling}}

File:Sperm whale head anatomy (transverse + sagittal).svg

The head of the sperm whale is filled with a waxy liquid called spermaceti. This liquid can be refined into spermaceti wax and sperm oil. These were much sought after by 18th-, 19th-, and 20th-century whalers. These substances found a variety of commercial applications, such as candles, soap, cosmetics, machine oil, other specialized lubricants, lamp oil, pencils, crayons, leather waterproofing, rustproofing materials, and many pharmaceutical compounds.{{cite book|title=The Smithsonian Book of North American Mammals|author=Wilson, D.|page= 300|year=1999|publisher=University of British Columbia Press |isbn=978-0-7748-0762-3}}

{{cite web|title=The status of natural resources on the high seas|url=http://cmsdata.iucn.org/downloads/highseas.pdf|author1=The Southampton Oceanography Centre|author2=A deFontaubert|name-list-style=amp|publisher=IUCN|page=63|access-date=2008-10-11|archive-url=https://web.archive.org/web/20081217073242/http://cmsdata.iucn.org/downloads/highseas.pdf|archive-date=2008-12-17|url-status=dead}}{{cite book|title=A Dictionary of Mechanical Science, Arts, Manufactures, and Miscellaneous Knowledge|url=https://archive.org/details/adictionarymech01jamigoog|author=Jamieson, A.|year=1829|page= [https://archive.org/details/adictionarymech01jamigoog/page/n18 566]|publisher=H. Fisher, Son & Co.}}{{cite web|title=Aquarium of the Pacific – Sperm Whale|url=http://www.aquariumofpacific.org/onlinelearningcenter/print/sperm_whale/|access-date=2008-10-11|archive-date=2019-03-14|archive-url=https://web.archive.org/web/20190314155801/http://www.aquariumofpacific.org/onlinelearningcenter/print/sperm_whale|url-status=dead}} Ambergris, a solid, waxy, flammable substance produced in the digestive system of sperm whales, was also sought as a fixative in perfumery.

Sperm whaling in the 18th century began with small sloops carrying only a pair of whaleboats (sometimes only one). As the scope and size of the fleet increased, so did the rig of the vessels change, as brigs, schooners, and finally ships and barks were introduced. In the 19th-century stubby, square-rigged ships (and later barks) dominated the fleet, being sent to the Pacific (the first being the British whaleship Emilia, in 1788),{{cite book|chapter-url=https://books.google.com/books?id=c2QmrE1Vu1YC&q=British+whaleship+%27%27Emilia%27%27+in+1778&pg=PA46|last=Schokkenbroek|first=Joost|title=Trying-out: An Anatomy of Dutch Whaling and Sealing in the Nineteenth Century|chapter=King Willem I and the Premium System|year=2008|access-date=25 November 2015|page=46|publisher=Amsterdam University Press |isbn=978-90-5260-283-7}} the Indian Ocean (1780s), and as far away as the Japan grounds (1820) and the coast of Arabia (1820s), as well as Australia (1790s) and New Zealand (1790s).{{cite book|title=Whales & Destiny: The Rivalry between America, France, and Britain for Control of the Southern Whale Fishery, 1785–1825|author=Stackpole, E. A.|year=1972|publisher=The University of Massachusetts Press|isbn=978-0-87023-104-9}}{{cite web|title=A Review of Cetaceans from Waters off the Arabian Peninsula|author=Baldwin, R.|author2=Gallagher, M.|author3=van Waerebeek, K.|name-list-style=amp|url=http://www.whalecoastoman.com/ArabPeninsula.pdf|page=6|access-date=2008-10-15|url-status=dead|archive-url=https://web.archive.org/web/20081217073246/http://www.whalecoastoman.com/ArabPeninsula.pdf|archive-date=2008-12-17}}

File:Down to the Sea in Ships sperm whaling sequence.ogv

Hunting for sperm whales during this period was notoriously dangerous for the crews of the 19th-century whaleboats. Though a properly harpooned sperm whale generally exhibited a fairly consistent pattern of trying to flee underwater to the point of exhaustion (at which point it would surface and offer no further resistance), it was not uncommon for bull whales to become enraged and turn to attack pursuing whaleboats on the surface, particularly if it had already been wounded by repeated harpooning attempts. A commonly reported tactic was for the whale to invert itself and violently thrash the surface of the water with its fluke, flipping and crushing nearby boats.

The estimated historic worldwide sperm whale population numbered 1,100,000 before commercial sperm whaling began in the early 18th century. By 1880, it had declined an estimated 29%.{{Cite iucn | author = Taylor, B.L. | author2 = Baird, R. | author3 = Barlow, J. | author4 = Dawson, S.M. | author5 = Ford, J. | author6 = Mead, J.G. | author7 = Notarbartolo di Sciara, G. | author8 = Wade, P. | author9 = Pitman, R.L. | name-list-style = amp | title = Physeter macrocephalus | volume = 2008 | page = e.T41755A10554884 | date = 2008 | doi = 10.2305/IUCN.UK.2008.RLTS.T41755A10554884.en }} From that date until 1946, the population appears to have recovered somewhat as whaling pressure lessened, but after the Second World War, with the industry's focus again on sperm whales, the population declined even further to only 33%. In the 19th century, between 184,000 and 236,000 sperm whales were estimated to have been killed by the various whaling nations,{{cite book|title=In Pursuit of Leviathan: Technology, Institutions, Productivity, and Profits in American Whaling, 1816–1906 (National Bureau of Economic Research Series on Long-Term Factors in Economic Dev)|author=Davis, L|author2=Gallman, R.|author3=Gleiter, K.|name-list-style=amp|page= 135|year=1997|publisher=University of Chicago Press|isbn=978-0-226-13789-6}} while in the modern era, at least 770,000 were taken, most between 1946 and 1980.Over 680,000 officially reported at {{cite web |title=Whaling Statistics |url=http://luna.pos.to/whale/sta.html |access-date=2008-10-15 |archive-date=2019-10-15 |archive-url=https://web.archive.org/web/20191015053920/http://luna.pos.to/whale/sta.html |url-status=dead }}. In addition, studies have found that official reports understated USSR catches by at least 89,000 {{cite web |title=Sperm Whale (Physeter macrocephalus) California/Oregon/Washington Stock |url=http://www.nmfs.noaa.gov/pr/pdfs/sars/po2007whsp-cow.pdf |access-date=2008-10-16 }}. Furthermore, other countries, such as Japan, have been found to have understated catches.{{cite web |title=The RMS – A Question of Confidence: Manipulations and Falsifications in Whaling |url=http://www.wdcs.org/submissions_bin/rmsreview.pdf |access-date=2008-10-16 |url-status=dead |archive-url=https://web.archive.org/web/20081007174536/http://www.wdcs.org/submissions_bin/rmsreview.pdf |archive-date=2008-10-07 }} Remaining sperm whale populations are large enough so that the species' conservation status is vulnerable, rather than endangered. However, the recovery from the whaling years is a slow process, particularly in the South Pacific, where the toll on males of breeding age was severe.{{cite book|title=Sperm Whales Social Evolution in the Ocean|author=Whitehead, H.|chapter=Ghosts of Whaling Past|pages=[https://archive.org/details/spermwhalessocia0000whit/page/360 360–362]|year=2003|publisher=University of Chicago Press|isbn=978-0-226-89518-5|chapter-url=https://archive.org/details/spermwhalessocia0000whit/page/360}}

{{Main|Dolphin drive hunting}}

File:Hvalba 26-08-06 (3).jpg caught in a drive hunt in Hvalba on the Faroe Islands being taken away with a forklift]]

Dolphins and porpoises are hunted in an activity known as dolphin drive hunting. This is done by driving a pod together with boats and usually into a bay or onto a beach. Their escape is prevented by closing off the route to the ocean with other boats or nets. Dolphins are hunted this way in several places around the world, including the Solomon Islands, the Faroe Islands, Peru, and Japan, the most well-known practitioner of this method. By numbers, dolphins are mostly hunted for their meat, though some end up in dolphinariums.{{cite newsgroup|first1=Yoko|last1=Wakatsuki|first2=Madison|last2=Park|title=Japan officials defend dolphin hunting at Taiji Cove|year=2014|access-date=}} Despite the controversial nature of the hunt resulting in international criticism, and the possible health risk that the often polluted meat causes,{{cite web|author= World Health Organization|author-link= World Health Organization|year= 2008 |title= Guidance for identifying populations at risk from mercury exposure|page= 36 |url=https://www.who.int/foodsafety/publications/chem/mercuryexposure.pdf |access-date= 29 August 2013}} thousands of dolphins are caught in drive hunts each year.{{cite newsgroup|first=Elahe|last=Izadi|title=Why more than 15,000 dolphins have been killed in Solomon Islands drive hunts|year=2014|access-date=25 November 2015|url=https://www.washingtonpost.com/news/speaking-of-science/wp/2015/05/09/why-more-than-15000-dolphins-have-been-killed-in-solomon-islands-drive-hunts/}}

In Japan, the hunting is done by a select group of fishermen.Paul Kenyon (2004), reporter for the BBC. [http://news.bbc.co.uk/2/hi/programmes/this_world/3956355.stm BBC's dining with the dolphin hunters], retrieved on June 21, 2008. When a pod of dolphins has been spotted, they are driven into a bay by the fishermen while banging on metal rods in the water to scare and confuse the dolphins. When the dolphins are in the bay, it is quickly closed off with nets so the dolphins cannot escape. The dolphins are usually not caught and killed immediately, but instead left to calm down over night. The following day, the dolphins are caught one by one and killed. The killing of the animals used to be done by slitting their throats, but the Japanese government banned this method, and now dolphins may officially only be killed by driving a metal pin into the neck of the dolphin, which causes them to die within seconds according to a memo from Senzo Uchida, the executive secretary of the Japan Cetacean Conference on Zoological Gardens and Aquariums.{{cite newsgroup|first=Kjeld|last=Duits| year=2005|access-date=|title=Activists Worldwide Protest Japan's Dolphin Slaughter}} A veterinary team's analysis of a 2011 video footage of Japanese hunters killing striped dolphins using this method suggested that, in one case, death took over four minutes.{{Cite journal | doi = 10.1080/10888705.2013.768925| title = A Veterinary and Behavioral Analysis of Dolphin Killing Methods Currently Used in the "Drive Hunt" in Taiji, Japan| journal = Journal of Applied Animal Welfare Science| volume = 16| issue = 2| pages = 184–204| year = 2013| last1 = Butterworth | first1 = A. | last2 = Brakes | first2 = P. | last3 = Vail | first3 = C. S. | last4 = Reiss | first4 = D. | pmid=23544757| citeseerx = 10.1.1.453.4156| s2cid = 3456395}}

Since much of the criticism is the result of photos and videos taken during the hunt and slaughter, it is now common for the final capture and slaughter to take place on site inside a tent or under a plastic cover, out of sight from the public. The most circulated footage is probably that of the drive and subsequent capture and slaughter process taken in Futo, Japan, in October 1999, shot by the Japanese animal welfare organization Elsa Nature Conservancy.{{cite AV media|first=Mark|last=Monroe|title=The Cove|type=Motion picture|year=2009|access-date=}} Part of this footage was, amongst others, shown on CNN. In recent years, the video has also become widespread on the internet and was featured in the animal welfare documentary Earthlings, though the method of killing dolphins as shown in this video is now officially banned. In 2009, a critical documentary on the hunts in Japan titled The Cove was released and shown amongst others at the Sundance Film Festival.{{cite newsgroup|author=Japan Times|title=Dolphin slaughter film a hit at Sundance|year=2009|access-date=25 November 2015|url=http://www.japantimes.co.jp/news/2009/01/27/news/dolphin-slaughter-film-a-hit-at-sundance/#.VlZRz_mrSUk|archive-date=7 April 2014|archive-url=https://web.archive.org/web/20140407133323/http://www.japantimes.co.jp/news/2009/01/27/news/dolphin-slaughter-film-a-hit-at-sundance/#.VlZRz_mrSUk|url-status=dead}}

Toothed whales can also be threatened by humans more indirectly. They are unintentionally caught in fishing nets by commercial fisheries as bycatch and accidentally swallow fishhooks. Gillnetting and Seine netting are significant causes of mortality in cetaceans and other marine mammals.{{cite web |url=http://swfsc.noaa.gov/textblock.aspx?Division=PRD&ParentMenuId=228&id=1408 |title=The Tuna-Dolphin Issue |author=NOAA Fisheries – Office of Protected Resources|work=noaa.gov |access-date=29 August 2015}} Porpoises are commonly entangled in fishing nets. Whales are also affected by marine pollution. High levels of organic chemicals accumulate in these animals since they are high in the food chain. They have large reserves of blubber, more so for toothed whales, as they are higher up the food chain than baleen whales. Lactating mothers can pass the toxins on to their young. These pollutants can cause gastrointestinal cancer and greater vulnerability to infectious diseases.{{cite web |last=Metcalfe |first=C. |date=23 February 2012 |title=Persistent organic pollutants in the marine food chain |publisher=United Nations University |url=http://unu.edu/publications/articles/persistent-organic-pollutants-in-the-marine-food-chain.html |access-date=16 August 2013 |archive-date=22 October 2019 |archive-url=https://web.archive.org/web/20191022142022/https://unu.edu/publications/articles/persistent-organic-pollutants-in-the-marine-food-chain.html |url-status=dead }} They may also swallow litter, such as plastic bags.{{cite news |url=http://www.taipeitimes.com/News/taiwan/archives/2015/07/03/2003622174 |title=Whales and trash-bags |author=Tsai, Wen-Chu |newspaper=Taipei Times |access-date=5 August 2015}} Pollution of the Yangtze river has led to the extinction of the baiji.{{cite web|url=http://wwf.panda.org/about_our_earth/about_freshwater/freshwater_problems/river_decline/10_rivers_risk/yangtze/yangtze_threats/|author=World Wildlife Fund|author-link=World Wildlife Fund|title=Threat of Pollution in the Yangtze|work=WWF}} Environmentalists speculate that advanced naval sonar endangers some whales. Some scientists suggest that sonar may trigger whale beachings, and they point to signs that such whales have experienced decompression sickness.{{cite journal|url=http://foodweb.uhh.hawaii.edu/MARE390_files/Rommel%20et%20al.%202006.pdf|author1=Rommel, S. A.|title=Elements of beaked whale anatomy and diving physiology and some hypothetical causes of sonar-related stranding|journal=Journal of Cetacean Research and Management|volume=7|issue=3|pages=189–209|year=2023|doi=10.47536/jcrm.v7i3.730 |s2cid=32951311 |access-date=29 August 2015|display-authors=etal|archive-date=25 September 2015|archive-url=https://web.archive.org/web/20150925113819/http://foodweb.uhh.hawaii.edu/MARE390_files/Rommel%20et%20al.%202006.pdf|url-status=dead}}{{cite journal |author=Schrope, Mark |title=Whale deaths caused by US Navy's sonar |journal=Nature |volume=415 |issue=6868 |page=106 |year=2003 |doi=10.1038/415106a|issn=1476-4687 |pmid=11805797|bibcode=2002Natur.415..106S|doi-access=free }}{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/3173942.stm |title=Sonar may cause Whale deaths |work=BBC News |date=8 October 2003 |access-date=14 September 2006 |first=Alex |last=Kirby}}{{cite journal |last1=Piantadosi|first1=C. A.|last2=Thalmann|first2=E. D.|journal=Nature |title=Pathology: whales, sonar and decompression sickness |date=2004 |volume=428 |issue=6894 |doi=10.1038/nature02527a |pmid=15085881 |pages=716–718|s2cid=4391838}}

Currently, no international convention gives universal coverage to all small whales, although the International Whaling Commission has attempted to extend its jurisdiction over them. ASCOBANS was negotiated to protect all small whales in the North and Baltic Seas and in the northeast Atlantic. ACCOBAMS protects all whales in the Mediterranean and Black Seas. The global UNEP Convention on Migratory Species currently covers seven toothed whale species or populations on its Appendix I, and 37 species or populations on Appendix II. All oceanic cetaceans are listed in CITES appendices, meaning international trade in them and products derived from them is very limited.{{cite web|url=http://www.cms.int/en/legalinstrument/accobams|author=Convention on the Conservation of Migratory Species|author-link=Convention on the Conservation of Migratory Species|title=ACCOBAMS|access-date=25 November 2015|work=CMS}}{{cite web|url=https://www.cites.org/|author=Convention on International Trade of Endangered Species of Wild Flora, Fauna|author-link=CITES|title=CITES}}

Many organizations are dedicated to protecting certain species that do not fall under any international treaty, such as CIRVA (Committee for the Recovery of the Vaquita),{{cite web|url=http://www.iucn-csg.org/index.php/vaquita/|title=Vaquita|author=Cetacean Specialist Group|work=International Union for Conservation of Nature|access-date=20 May 2016|date=March 2015}} and the Wuhan Institute of Hydrobiology (for the Yangtze finless porpoise).{{cite journal|url=http://people.cst.cmich.edu/swans1bj/Wang_etal_06_Baiji_cons.pdf|first1=Ding|last1=Wang|first2=Xiangfeng|last2=Zhang|first3=Kexiong|last3=Wang|first4=Zhuo|last4=Wei| first5=Bernd|last5=Würsig|year=2006|title=Conservation of the Baiji: No Simple Solution|journal=Conservation Biology|volume=20|issue=3|page=624|doi=10.1111/j.1523-1739.2006.00471.x|pmid=16909544|bibcode=2006ConBi..20..623W | s2cid=7024386 }}

{{Main|Cetaceans in captivity|Dolphinarium}}

File:2009-Seaworld-Shamu.jpg

Various species of toothed whales, mainly dolphins, are kept in captivity, as well as several other species of porpoise such as harbour porpoises and finless porpoises. These small cetaceans are more often than not kept in theme parks, such as SeaWorld, commonly known as a dolphinarium. Bottlenose dolphins are the most common species kept in dolphinariums, as they are relatively easy to train, have a long lifespan in captivity, and have a friendly appearance. Hundreds if not thousands of bottlenose dolphins live in captivity across the world, though exact numbers are hard to determine. Orca are well known for their performances in shows, but the number kept in captivity is very small, especially when compared to the number of bottlenose dolphins, with only 44 captives being held in aquaria as of 2012.{{cite web|url=http://www.orcahome.de/orcastat.htm| title=Orcas in Captivity - A look at killer whales in aquariums and parks|date=23 November 2009 |access-date=6 September 2015}} Other species kept in captivity are spotted dolphins, false killer whales, and common dolphins, Commerson's dolphins, as well as rough-toothed dolphins, but all in much lower numbers than the bottlenose dolphin. Also, fewer than ten pilot whales, Amazon river dolphins, Risso's dolphins, spinner dolphins, or tucuxi are in captivity. Two unusual and very rare hybrid dolphins, known as wolphins, are kept at the Sea Life Park in Hawaii, which is a cross between a bottlenose dolphin and a false killer whale. Also, two common/bottlenose hybrids reside in captivity: one at Discovery Cove and the other at SeaWorld San Diego.{{cite web|url=http://www.ceta-base.org/captive/cetacean/species.html|author=Captive Cetacean Database|title=Ceta-Base: Captive Cetaceans|year=2006|access-date=25 November 2015|work=ceta-base.org|archive-url=https://web.archive.org/web/20151126110259/http://www.ceta-base.org/captive/cetacean/species.html|archive-date=26 November 2015|url-status=dead}}

{{See also|SeaWorld#Criticism and resulting impact|Incidents at SeaWorld parks}}

Organizations such as the Animal Welfare Institute and Whale and Dolphin Conservation campaign against the captivity of dolphins and orcas.{{cite web|title=Poll Reveals Americans Oppose Keeping Orcas in Captivity for Public Display|year=2012 |url=http://www.humanesociety.org/news/press_releases/2012/07/poll_reveals_americans_oppose_orca_captivity_071612.html?credit=web_id95800657|publisher=Humane Society of the United States|access-date=11 June 2016}} SeaWorld faced a lot of criticism after the documentary Blackfish was released in 2013.{{cite news|url=http://www.bbc.com/earth/story/20160310-why-killer-whales-should-not-be-kept-in-captivity|first=Melissa|last=Hogenboom|year=2016|title=Why killer whales should not be in captivity|publisher=BBC–Earth|access-date=11 June 2016}}

Aggression among captive orca is common. In August 1989, a dominant female orca, Kandu V, tried to rake a newcomer whale, Corky II, with her mouth during a live show, and smashed her head into a wall. Kandu V broke her jaw, which severed an artery, and then bled to death.{{Cite journal | last1 = Parsons | first1 = E. C. M. | title = Killer Whale Killers | doi = 10.3727/154427312X13491835451494 | journal = Tourism in Marine Environments | volume = 8 | issue = 3 | pages = 153–160 | year = 2012 }} In November 2006, a dominant female killer whale, Kasatka, repeatedly dragged experienced trainer Ken Peters to the bottom of the stadium pool during a show after hearing her calf crying for her in the back pools.{{cite web|url=http://www.huffingtonpost.com/david-kirby/near-death-at-seaworld-wo_b_1697243.html|title=Near Death At SeaWorld: Worldwide Exclusive Video|work=The Huffington Post|access-date=July 12, 2015|date=2012-07-24}} In February 2010, an experienced female trainer at SeaWorld Orlando, Dawn Brancheau, was killed by orca Tilikum shortly after a show in Shamu Stadium.{{cite newsgroup|url=http://www.cnn.com/2010/US/02/24/killer.whale.trainer.death/index.html?eref=igoogle_cnn|title=SeaWorld trainer killed by killer whale|access-date=February 24, 2010 | date=February 25, 2010}} Tilikum had been associated with the deaths of two people previously.{{cite newsgroup|title=Animal trainer killed at SeaWorld|url=https://www.latimes.com/archives/la-xpm-2010-feb-25-la-na-seaworld-death25-2010feb25-story.html|date=February 25, 2010|first1=Jason|last1=Garcia|first2=Susan|last2=Jacobson}} In May 2012, Occupational Safety and Health Administration administrative law judge Ken Welsch cited SeaWorld for two violations in the death of Dawn Brancheau and fined the company a total of US$12,000.{{cite web|title=Secretary of Labor, Complainant v. SeaWorld of Florida - Decision and Order|url=http://www.oshrc.gov/foia/SecLabSeaWorld/Sea-World_ALJ.pdf|access-date=June 13, 2012|archive-date=June 8, 2012|archive-url=https://web.archive.org/web/20120608211034/http://www.oshrc.gov/foia/SecLabSeaWorld/Sea-World_ALJ.pdf}} Trainers were banned from making close contact with the orca.{{cite newsgroup|last=Karlamangla|first=Soumya|title=Killer whales: Court weighs lifting ban on trainer-orca contact|url=http://www.latimes.com/nation/nationnow/la-na-nn-seaworld-killer-whales-20131112,0,7762020.story#axzz2tcIRmSpf|date=November 13, 2013}} In April 2014, the US Court of Appeals for the District of Columbia denied an appeal by SeaWorld.{{citation|title=SeaWorld appeal of OSHA citations denied|date=11 April 2014 |url=http://edition.cnn.com/2014/04/11/us/seaworld-ruling/}}

In 2013, SeaWorld's treatment of orca in captivity was the basis of the movie Blackfish, which documents the history of Tilikum, an orca captured by SeaLand of the Pacific, later transported to SeaWorld Orlando, which has been involved in the deaths of three people.{{cite newsgroup|last=Whiting|first=Candace|url=http://www.huffingtonpost.com/candace-calloway-whiting/blackfish-killer-whales_b_4166923.html|title=In the Wake of Blackfish -- Is it Time to Retire the Last Killer Whale Whose Capture Was Shown in the Film?|year=2013|access-date=29 November 2015}} In the aftermath of the release of the film, Martina McBride, 38 Special, REO Speedwagon, Cheap Trick, Heart, Trisha Yearwood, and Willie Nelson cancelled scheduled concerts at SeaWorld parks.{{cite newsgroup| url=http://www.cnn.com/2013/12/16/showbiz/seaworld-martina-mcbride-cancels/| title=Martina McBride, 38 Special, cancel SeaWorld gig over 'Blackfish'| date=December 16, 2013}} SeaWorld disputes the accuracy of the film, and in December 2013 released an ad countering the allegations and emphasizing its contributions to the study of cetaceans and their conservation.{{cite web|last=Bazzle|first=Steph|title=SeaWorld Tries to Combat Animal Abuse Allegations|url=http://www.indyposted.com/226354/seaworld-tries-combat-animal-abuse-allegations/|publisher=Indyposted|access-date=December 26, 2013|date=December 20, 2013|url-status=dead|archive-url=https://web.archive.org/web/20131227150113/http://www.indyposted.com/226354/seaworld-tries-combat-animal-abuse-allegations/|archive-date=December 27, 2013}}

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