Editing Orca (section)

==Feeding==
{{multiple image
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| image1 = Orcinus orca (Vestfjord).jpg
| caption1 = Tail-slapping in [[Vestfjorden]], Norway
| image2 = Killer Whale chasing Chinook.jpg
| caption2 = Resident orca pursuing a chinook salmon
}}

Orcas are [[apex predator]]s, meaning that they themselves have no natural predators. They are sometimes called "wolves of the sea", because they hunt in groups like wolf packs.<ref name=marinebio>{{cite web|url=http://marinebio.org/species.asp?id=84|title=''Orcinus orca''&nbsp;– Orca (Killer Whale)|access-date=June 26, 2007|publisher=Marinebio.org|archive-date=July 13, 2012|archive-url=https://archive.today/20120713081944/http://marinebio.org/species.asp?id=84|url-status=deviated}}</ref> Orcas hunt varied prey including fish, [[cephalopod]]s, mammals, [[seabird]]s, and [[sea turtles]].{{sfn|NMFS|2005|p=17}} Different populations or ecotypes may specialize, and some can have a dramatic impact on prey species.<ref>{{cite journal|author= Morell|first1= Virginia |title= Killer Whales Earn Their Name |journal=Science|pages= 274–276 |volume= 331 |year= 2011|doi= 10.1126/science.331.6015.274|pmid= 21252323|issue= 6015|bibcode= 2011Sci...331..274M }}</ref> However, whales in tropical areas appear to have more generalized diets due to lower food productivity.<ref name="Baird2006">{{cite journal|author=Baird|first1= R. W.|display-authors=etal|year=2006|title=Killer whales in Hawaiian waters: information on population identity and feeding habits|journal=Pacific Science|volume=60|issue=4|pages=523–530|doi=10.1353/psc.2006.0024|url=http://www.cascadiaresearch.org/files/Projects/Hawaii/Baird%20et%20al%20Hawaii%20killer%20whales.pdf|hdl=10125/22585|s2cid=16788148|access-date=October 23, 2017|archive-date=October 23, 2017|archive-url=https://web.archive.org/web/20171023063253/http://www.cascadiaresearch.org/files/Projects/Hawaii/Baird%20et%20al%20Hawaii%20killer%20whales.pdf|url-status=live|hdl-access=free}}</ref><ref name="Wier">{{cite journal|author=Weir|first1= C. R.|last2=Collins|first2= T.|last3=Carvalho|first3= I.|last4=Rosenbaum|first4= H. C.|year=2010|title=Killer whales (''Orcinus orca'') in Angolan and Gulf of Guinea waters, tropical West Africa|journal=Journal of the Marine Biological Association of the United Kingdom|volume=90|issue=8|pages=1601–1611|doi=10.1017/S002531541000072X|bibcode= 2010JMBUK..90.1601W|s2cid=84721171|url=http://www.escolademar.pt/wp-content/uploads/pdf_docs/artigos/Weir_et_al_2010_final.pdf|archive-url=http://arquivo.pt/wayback/20140930081828/http://www.escolademar.pt/wp%2Dcontent/uploads/pdf_docs/artigos/Weir_et_al_2010_final.pdf|url-status=dead|archive-date=September 30, 2014}}</ref> Orcas spend most of their time at shallow depths,<ref>{{cite journal |last1=Miller |first1=Patrick James O'Malley |last2=Shapiro |first2=Ari Daniel |last3=Deecke |first3=Volker Bernt |title=The diving behaviour of mammal-eating killer whales : variations with ecological not physiological factors |journal=Canadian Journal of Zoology |date=November 2010 |volume=88 |issue=11 |pages=1103–1112 |doi=10.1139/Z10-080 |url=http://insight.cumbria.ac.uk/id/eprint/1976/1/Deecke_TheDivingBehaviour.pdf |quote=Overall, the whales spent 50% of their time 8 m or shallower and 90% of their time 40 m or shallower |access-date=August 23, 2020 |archive-date=July 20, 2018 |archive-url=https://web.archive.org/web/20180720202137/http://insight.cumbria.ac.uk/id/eprint/1976/1/Deecke_TheDivingBehaviour.pdf |url-status=live }}</ref> but occasionally dive several hundred metres depending on their prey.<ref>{{cite journal |last1=Reisinger |first1=Ryan R. |last2=Keith |first2=Mark |last3=Andrews |first3=Russel D. |last4=de Bruyn |first4=P. J. N. |title=Movement and diving of killer whales (''Orcinus orca'') at a Southern Ocean archipelago |journal=Journal of Experimental Marine Biology and Ecology |date=December 2015 |volume=473 |pages=90–102 |doi=10.1016/j.jembe.2015.08.008 |bibcode=2015JEMBE.473...90R |quote=maximum dive depths were 767.5 and 499.5 m |hdl=2263/49986 |url=https://figshare.com/articles/poster/Movement_and_diving_of_killer_whales_Orcinus_orca_at_a_Southern_Ocean_archipelago/3426920 |hdl-access=free |access-date=December 6, 2021 |archive-date=June 30, 2022 |archive-url=https://web.archive.org/web/20220630074802/https://figshare.com/articles/poster/Movement_and_diving_of_killer_whales_Orcinus_orca_at_a_Southern_Ocean_archipelago/3426920 |url-status=live }}</ref><ref>{{cite journal |last1=Towers |first1=Jared R |last2=Tixier |first2=Paul |last3=Ross |first3=Katherine A |last4=Bennett |first4=John |last5=Arnould |first5=John P Y |last6=Pitman |first6=Robert L |last7=Durban |first7=John W |last8=Northridge |first8=Simon |title=Movements and dive behaviour of a toothfish-depredating killer and sperm whale |journal=ICES Journal of Marine Science |date=January 2019 |volume=76 |issue=1 |pages=298–311 |doi=10.1093/icesjms/fsy118 |s2cid=91256980 |quote=The killer whale dove >750 m on five occasions while depredating (maximum: 1087 m), but these deep dives were always followed by long periods (3.9–4.6 h) of shallow (<100 m) diving.|doi-access=free |hdl=10536/DRO/DU:30120094 |hdl-access=free }}</ref>

===Fish===
Fish-eating orcas prey on around 30 species of fish. Some populations in the [[Norway|Norwegian]] and [[Greenland]] sea specialize in [[herring]] and follow that fish's autumnal migration to the Norwegian coast. [[Salmon]] account for 96% of northeast Pacific residents' diet, including 65% of large, fatty [[Chinook salmon|Chinook]].{{sfn|NMFS|2005|p=18}} [[Chum salmon]] are also eaten, but smaller [[Sockeye salmon|sockeye]] and [[pink salmon]] are not a significant food item. Depletion of specific prey species in an area is, therefore, cause for concern for local populations, despite the high diversity of prey.{{sfn|Ford|Ellis|2006}} On average, an orca eats {{convert|227|kg|lb}} each day.<ref>{{cite web |url=https://kids.nationalgeographic.com/animals/mammals/facts/orca |title=National Geographic creature feature|last1=Hughes |first1=Catherine D.|date=March 2014 |access-date=July 25, 2007<!--valid url/arch confirm :11 23 June 2023 Dave-->|archive-date=June 2, 2023 |archive-url=https://web.archive.org/web/20230602193556/https://kids.nationalgeographic.com/animals/mammals/facts/orca |url-status=live }}</ref> While salmon are usually hunted by an individual whale or a small group, herring are often caught using [[carousel feeding]]: the orcas force the herring into a tight ball by releasing bursts of bubbles or flashing their white undersides. They then slap the ball with their tail flukes, stunning or killing up to 15 fish at a time, then eating them one by one. Carousel feeding has been documented only in the Norwegian orca population, as well as some oceanic dolphin species.<ref>{{Cite journal |last1=Similä|first1= T. |last2=Ugarte|first2= F. |year=1993 |title=Surface and underwater observations of cooperatively feeding killer whales in Northern Norway |journal=Canadian Journal of Zoology |volume=71 |pages=1494–1499 |doi=10.1139/z93-210 |issue=8|bibcode= 1993CaJZ...71.1494S }}</ref>

In New Zealand, [[shark]]s and [[Batoidea|rays]] appear to be important prey, including [[New Zealand eagle ray|eagle ray]]s, [[Thorntail stingray|long-tail]] and [[short-tail stingray]]s, [[common thresher]]s, [[smooth hammerhead]]s, [[blue shark]]s, [[basking sharks]], and [[shortfin mako]]s.<ref name=orcashark>{{cite journal|author=Visser|first1= Ingrid N.|year=2005|title=First Observations of Feeding on Thresher (''Alopias vulpinus'') and Hammerhead (''Sphyrna zygaena'') Sharks by Killer Whales (''Orcinus orca'') Specialising on Elasmobranch Prey|journal=Aquatic Mammals|volume=31|issue=1|pages=83–88|doi=10.1578/AM.31.1.2005.83}}</ref><ref>{{cite journal |last1=Visser|first1= Ingrid N. |first2=Jo|last2= Berghan |last3= van Meurs|first3= Rinie|first4=Dagmar |last4=Fertl |year=2000 |title=Killer Whale (''Orcinus orca'') Predation on a Shortfin Mako Shark (''Isurus oxyrinchus'') in New Zealand Waters |journal=Aquatic Mammals |volume=26 |issue=3 |pages=229–231 |url=http://aquaticmammalsjournal.org/share/AquaticMammalsIssueArchives/2000/AquaticMammals_26-03/26-03_Berghan.pdf |access-date=May 3, 2014 |archive-date=January 26, 2012 |archive-url= https://web.archive.org/web/20120126035026/http://aquaticmammalsjournal.org/share/AquaticMammalsIssueArchives/2000/AquaticMammals_26-03/26-03_Berghan.pdf |url-status=live }}</ref> With sharks, orcas may herd them to the surface and strike them with their tail flukes,<ref name=orcashark/> while bottom-dwelling rays are cornered, pinned to the ground and taken to the surface.<ref>{{cite journal|author=Visser|first1= Ingrid N.|year=1999|title=Benthic foraging on stingrays by killer whales (''Orcinus orca'') in New Zealand waters|journal=Marine Mammal Science|volume=15|issue=1|pages=220–227 |doi=10.1111/j.1748-7692.1999.tb00793.x|bibcode= 1999MMamS..15..220V}}</ref> In other parts of the world, orcas have preyed on [[broadnose sevengill shark]]s,<ref name=Engelbrecht/> [[whale shark]]s,<ref>{{cite web |last1=O'Sullivan |first1=J. B. |title=A fatal attack on a whale shark ''Rhincodon typus'', by killer whales ''Orcinus orca'' off Bahia de Los Angeles, Baja California |year=2000 |url=http://www.flmnh.ufl.edu/fish/meetings/abst2000c.htm |work=American Elasmobranch Society 16th Annual Meeting, June 14–20, 2000 |location=La Paz, B.C.S., México |access-date=February 18, 2010 |archive-date=February 28, 2010 |archive-url=https://web.archive.org/web/20100228204745/http://www.flmnh.ufl.edu/fish/meetings/abst2000c.htm |url-status=dead }}</ref><ref>{{Cite journal |last1=Pancaldi |first1=Francesca |last2=Ayres |first2=Kathryn A. |last3=Gallagher |first3=Austin J. |last4=Moskito |first4=James |last5=Williamson |first5=Kelsey C. |last6=Higuera Rivas |first6=Jesús Erick |date=2024-11-29 |title=Killer whales (Orcinus orca) hunt, kill and consume the largest fish on Earth, the whale shark (Rhincodon typus) |journal=Frontiers in Marine Science |language=English |volume=11 |doi=10.3389/fmars.2024.1448254 |doi-access=free |issn=2296-7745}}</ref> and even [[great white shark]]s.<ref name=Engelbrecht>{{cite journal|last1=Engelbrecht|first1=T. M.|last2=Kock|first2= A. A.|last3=O'Riain|first3= M. J.|year=2019|title=Running scared: when predators become prey|journal=Ecosphere |volume=10|issue=1|page=e02531 |doi=10.1002/ecs2.2531|doi-access=free|bibcode=2019Ecosp..10E2531E }}</ref><ref name=Pyle>{{cite journal |last1=Pyle |first1=Peter |last2=Schramm|first2= Mary Jane |last3=Keiper|first3= Carol |last4=Anderson|first4= Scot D. |title=Predation on a white shark (''Carcharodon carcharias'') by a killer whale (''Orcinus orca'') and a possible case of competitive displacement |journal=[[Marine Mammal Science]] |year=1999 |url=http://www.prbo.org/cms/docs/marine/MMS.pdf |volume=15 |issue=2 |pages=563–568 |doi=10.1111/j.1748-7692.1999.tb00822.x |bibcode=1999MMamS..15..563P |access-date=April 28, 2014 |archive-date=March 22, 2012 |archive-url=https://web.archive.org/web/20120322070431/http://www.prbo.org/cms/docs/marine/MMS.pdf |url-status=dead }}</ref> Competition between orcas and white sharks is probable in regions where their diets overlap.<ref>{{cite journal |last=Heithaus |first=Michael |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 |year=2001 |url=http://www.science.fau.edu/sharklab/courses/elasmobiology/readings/heithaus.pdf |doi=10.1017/S0952836901000061 |citeseerx=10.1.1.404.130 |access-date=January 18, 2010 |archive-url=https://web.archive.org/web/20160115113304/http://www.science.fau.edu/sharklab/courses/elasmobiology/readings/heithaus.pdf |archive-date=January 15, 2016 |url-status=dead }}</ref> The arrival of orcas in an area can cause white sharks to flee and forage elsewhere.<ref>{{cite journal|author=Jorgensen|first1= S. J.|display-authors=etal|year=2019 |title=Killer whales redistribute white shark foraging pressure on seals|journal=Scientific Reports|volume=9|issue=1|page=6153 |doi=10.1038/s41598-019-39356-2 |pmid=30992478|pmc=6467992|bibcode=2019NatSR...9.6153J}}</ref><ref>{{Cite journal |last1=Towner |first1=AV |last2=Watson |first2=RGA |last3=Kock |first3=AA |last4=Papastamatiou |first4=Y |last5=Sturup |first5=M |last6=Gennari |first6=E |last7=Baker |first7=K |last8=Booth |first8=T |last9=Dicken |first9=M |last10=Chivell |first10=W |last11=Elwen |first11=S |date=2022-04-03 |title=Fear at the top: killer whale predation drives white shark absence at South Africa's largest aggregation site |url=https://doi.org/10.2989/1814232X.2022.2066723 |journal=African Journal of Marine Science |volume=44 |issue=2 |pages=139–152 |doi=10.2989/1814232X.2022.2066723 |bibcode=2022AfJMS..44..139T |s2cid=250118179 |issn=1814-232X}}</ref> Orcas appear to target the liver of sharks.<ref name=Engelbrecht/><ref name=Pyle/> In one case a single orca was observed killing and eating a great white shark on its own.<ref>{{Cite journal |last1=Towner |first1=A |last2=Micarelli |first2=P |last3=Hurwitz |first3=D |last4=Smale |first4=Mj |last5=Booth |first5=Aj |last6=Stopforth |first6=C |last7=Jacobs |first7=E |last8=Reinero |first8=Fr |last9=Ricci |first9=V |last10=Di Bari |first10=A |last11=Gavazzi |first11=S |last12=Carugno |first12=G |last13=Mahrer |first13=M |last14=Gennari |first14=E |date=2024 |title=Further insights into killer whales Orcinus orca preying on white sharks Carcharodon carcharias in South Africa |url=https://www.tandfonline.com/doi/full/10.2989/1814232X.2024.2311272 |journal=African Journal of Marine Science |volume=46 |issue=1 |language=en |pages=1–5 |doi=10.2989/1814232X.2024.2311272 |bibcode=2024AfJMS..46....1T |issn=1814-232X}}</ref>

===Mammals and birds===
Orcas are sophisticated and effective predators of [[marine mammal]]s. They are recorded to prey on other cetacean species, usually smaller dolphins and [[porpoise]]s such as [[common dolphin]]s, [[bottlenose dolphin]]s, [[Pacific white-sided dolphin]]s, [[dusky dolphin]]s, [[harbour porpoise]]s and [[Dall's porpoise]]s.<ref name=Perrin/><ref name=Perrin2/> While hunting these species, orcas usually have to chase them to exhaustion. For highly social species, orca pods try to separate an individual from its group. Larger groups have a better chance of preventing their prey from escaping, which is killed by being thrown around, rammed and jumped on. Arctic orcas may attack [[beluga whale]]s and [[narwhal]]s stuck in pools enclosed by sea ice, the former are also driven into shallower water where juveniles are grabbed.<ref name=Perrin/> By contrast, orcas appear to be wary of [[pilot whale]]s, which have been recorded to [[Mobbing (animal behavior)|mob]] and chase them.<ref>{{cite journal|author=Selbmann, A.|display-authors=etal|year=2022|title=Occurrence of long-finned pilot whales (''Globicephala melas'') and killer whales (''Orcinus orca'') in Icelandic coastal waters and their interspecific interactions|journal=Acta Ethol|volume=25 |issue=3 |pages=141–154 |doi=10.1007/s10211-022-00394-1|pmid=35694552 |pmc=9170559 |s2cid=249487897 }}</ref> Nevertheless, possible predation on [[long-finned pilot whales]] has been recorded in [[Iceland]], and one study suggests [[short-finned pilot whales]] are among Caribbean Orcas' prey.<ref>{{cite journal |first= Filipa |last= Samarra |title= Prey of killer whales (Orcinus orca) in Iceland |journal= PLOS ONE |year= 2018 |volume= 13 |issue= 12 |page= 6|doi= 10.1371/journal.pone.0207287|doi-access= free |pmid= 30540762 |pmc= 6291266 |bibcode= 2018PLoSO..1307287S |hdl= 20.500.11815/1095 |hdl-access= free }}</ref><ref>{{cite journal |first= Jeremy |last= Kiszka |title= Feeding Ecology of Elusive Caribbean Killer Whales Inferred From Bayesian Stable Isotope Mixing Models and Whalers' Ecological Knowledge |journal= Frontiers in Marine Science |year= 2021 |volume= 8 |doi= 10.3389/fmars.2021.648421|doi-access= free }}</ref> Killer whales have been recorded attacking short-finned pilot whales in [[Peru]] as well.<ref>{{cite journal |last= Gonzalez-Pestana |first= Adriana |title= Killer whale (Orcinus Orca) occurrence and interactions with marine mammals off Peru |journal= Pacific Science |year= 2019 |volume=73 |issue= 2 |pages= 262–273 |doi= 10.2984/73.2.7}}</ref>

[[File:KW attack STBW.jpg|thumb|upright=1.36|Orca attacking a [[Strap-toothed whale|strap-toothed beaked whale]]]]
Orcas also prey on larger species such as [[sperm whale]]s, [[grey whale]]s, [[humpback whale]]s and [[minke whales]].<ref name=Perrin/><ref name=Perrin2/> On three separate occasions in 2019 orcas were recorded to have killed [[blue whale]]s off the south coast of Western Australia, including an estimated {{convert|18|–|22|m|sp=us|adj=on}} individual.<ref>{{cite journal|author1=Totterdell, J. A.|author2=Wellard, R.|author3=Reeves, I. M.|author4=Elsdon, B.|author5=Markovic, P.|author6=Yoshida, M.|author7=Fairchild, A.|author8=Sharp, G.|author9=Pitman, R.|year=2022|title=The first three records of killer whales (''Orcinus orca'') killing and eating blue whales (''Balaenoptera musculus'')|journal=Marine Mammal Science|volume=38 |issue=3 |pages=1286–1301 |doi=10.1111/mms.12906|bibcode=2022MMamS..38.1286T | s2cid=246167673 }}</ref> Large whales require much effort and coordination to kill and orcas often target calves. A hunt begins with a chase followed by a violent attack on the exhausted prey. Large whales often show signs of orca attack via tooth rake marks.<ref name=Perrin/> Pods of female sperm whales sometimes protect themselves by forming a protective circle around their calves with their flukes facing outwards, using them to repel the attackers.<ref>{{cite journal|doi=10.1111/j.1748-7692.2001.tb01000.x|author=Pitman|first1= Robert L.|url=http://digitalcommons.unl.edu/usdeptcommercepub/507/|title=Killer Whale Predation on Sperm Whales: Observations and Implications|journal=Marine Mammal Science|volume=17|issue=3|pages=494–507|year=2001|bibcode=2001MMamS..17..494P |display-authors=etal|access-date=February 25, 2014|archive-date=December 11, 2015|archive-url=https://web.archive.org/web/20151211133004/http://digitalcommons.unl.edu/usdeptcommercepub/507/|url-status=live}}</ref> There is also evidence that humpback whales will defend against or mob orcas who are attacking either humpback calves or juveniles as well as members of other species.<ref name=mobbing>{{cite journal|title=Humpback whales interfering when mammal-eating killer whales attack other species: Mobbing behavior and interspecific altruism?|journal=Marine Mammal Science | doi=10.1111/mms.12343|volume=33|pages=7–58|year=2016 | last1 = Pitman | first1 = Robert L.|doi-access=free}}</ref>

[[History of whaling|Prior to the advent of industrial whaling]], great whales may have been the major food source for orcas. The introduction of modern whaling techniques may have aided orcas by the sound of [[Harpoon cannon|exploding harpoons]] indicating the availability of prey to scavenge, and compressed air inflation of whale carcasses causing them to float, thus exposing them to scavenging. However, the devastation of great whale populations by unfettered whaling has possibly reduced their availability for orcas, and caused them to expand their consumption of smaller marine mammals, thus contributing to the decline of these as well.<ref name="EMM2009">{{cite book|last=Estes|first=James|editor=Perrin, William F.|others=Wursig, Bernd & Thewissen, J. G. M.|title=Encyclopedia of Marine Mammals|chapter-url=https://books.google.com/books?id=2rkHQpToi9sC&pg=PA360|date=February 26, 2009|publisher=Academic Press|isbn=978-0-08-091993-5|pages=357–361|chapter=Ecological effects of marine mammals|access-date=December 30, 2015|archive-date=May 9, 2016|archive-url=https://web.archive.org/web/20160509133131/https://books.google.com/books?id=2rkHQpToi9sC&pg=PA360|url-status=live}}</ref>

{{multiple image
| align = right
| direction = vertical
| image1=Orcas in Punta Norte Valdes Peninsula - panoramio.jpg|
| caption1= Orca beaching to capture sea lion along [[Valdes Peninsula]]
| image2=Killer Whales Hunting a Crabeater Seal.jpg
| caption2=Orcas swimming in close synchronization to create a wave to wash the [[crabeater seal]] off the floe
}}
Other marine mammal prey includes [[pinniped|seal]] species such as [[harbour seal]]s, [[elephant seal]]s, [[California sea lion]]s, [[Steller sea lion]]s, [[South American sea lion]]s and [[walrus]]es.<ref name=Perrin>{{cite book|editor-first1=William F.|editor-last1=Perrin|editor-first2=Bernd |editor-last2= Wursig|editor-first3=J. G. M. 'Hans' |editor-last3=Thewissen|title=Encyclopedia of Marine Mammals|year=2009|publisher=Academic Press|isbn=978-0-08-091993-5|last=Weller|first=D. W. |contribution=Predation on marine mammals|pages=927–930}}</ref><ref name=Perrin2/> Often, to avoid injury, orcas disable their prey before killing and eating it. This may involve throwing it in the air, slapping it with their tails, ramming it, or breaching and landing on it.{{sfn|Heimlich|Boran|2001|p=45}} In steeply banked beaches off [[Península Valdés]], Argentina, and the [[Crozet Islands]], orcas feed on South American sea lions and [[southern elephant seal]]s in shallow water, even [[beached whale|beaching]] temporarily to grab prey before wriggling back to the sea. Beaching, usually fatal to cetaceans, is not an instinctive behaviour, and can require years of practice for the young.{{sfn|Carwardine|2001|p=29}} Orcas can then release the animal near juvenile whales, allowing the younger whales to practice the difficult capture technique on the now-weakened prey.{{sfn|Heimlich|Boran|2001|p=45}}{{sfn|Baird|2002|pp=61–62}} In the Antarctic, type B orcas hunt [[Weddell seal]]s and other prey by "wave-hunting". They [[Cetacean surfacing behaviour#Spyhopping|"spy-hop"]] to locate them resting on ice floes, and then swim in groups to create waves that wash over the floe. This washes the prey into the water, where other orcas lie in wait.<ref>{{cite journal|last1=Pitman|first1=R. L.|last2=Durban|first2=J. W.|year=2011|title=Cooperative hunting behavior, prey selectivity and prey handling by pack ice killer whales (''Orcinus orca''), type B, in Antarctic Peninsula waters|journal=Marine Mammal Science|volume=28|issue=1|pages=16–36|doi=10.1111/j.1748-7692.2010.00453.x|url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1305&context=usdeptcommercepub|access-date=July 27, 2023|archive-date=August 2, 2023|archive-url=https://web.archive.org/web/20230802073930/https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1305&context=usdeptcommercepub|url-status=live}}</ref><ref>{{cite journal|last1=Visser |first1=Ingrid N. |last2=Smith |first2=Thomas G. |last3=Bullock |first3=Ian D. |last4=Green |first4=Geoffrey D. |last5=Carlsson |first5=Olle G. L. |last6=Imberti |first6=Santiago |doi=10.1111/j.1748-7692.2007.00163.x |title=Antarctic peninsula killer whales (''Orcinus orca'') hunt seals and a penguin on floating ice |year=2008 |pages=225–234 |volume=24 |journal=Marine Mammal Science |url=http://www.grupofalco.com.ar/pedefes/Visser%20et%20al%202008.%20Antarctic%20killer%20whales%20on%20ice%20-%20Marine%20Mammals%20Science.pdf |issue=1 |bibcode=2008MMamS..24..225V |url-status=dead |archive-url=https://web.archive.org/web/20110531161550/http://www.grupofalco.com.ar/pedefes/Visser%20et%20al%202008.%20Antarctic%20killer%20whales%20on%20ice%20-%20Marine%20Mammals%20Science.pdf |archive-date=May 31, 2011 }}</ref>

In the [[Aleutian Islands]], a decline in [[sea otter]] populations in the 1990s was controversially attributed by some scientists to orca predation, although with no direct evidence.<ref>Pinell, Nadine, et al. "[http://wildwhales.org/?p=132 Transient Killer Whales&nbsp;– Culprits in the Decline of Sea Otters in Western Alaska?] {{Webarchive|url=https://web.archive.org/web/20170630063238/http://wildwhales.org/?p=132 |date=June 30, 2017 }}" B.C. Cetacean Sightings Network, June 1, 2004. Retrieved March 13, 2010</ref> The decline of sea otters followed a decline in seal populations,{{efn|According to Baird,{{sfn|Baird|2002|p=23}} killer whales prefer harbour seals to sea lions and porpoises in some areas.}}<ref>[http://www.gi.alaska.edu/ScienceForum/ASF14/1418.html Killer Whales Develop a Taste For Sea Otters] {{Webarchive|url=https://web.archive.org/web/20151107004222/http://www2.gi.alaska.edu/ScienceForum/ASF14/1418.html |date=November 7, 2015 }} Ned Rozell, Article #1418, Alaska Science Forum, December 10, 1998. Retrieved February 26, 2010</ref> which in turn may be substitutes for their original prey, now decimated by industrial whaling.<ref>{{cite journal|last1=Springer|first1=A. M.|title=Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?|journal=Proceedings of the National Academy of Sciences|volume=100|pages=12223–12228|year=2003|doi=10.1073/pnas.1635156100|issue=21|bibcode=2003PNAS..10012223S|pmid=14526101|pmc=218740|doi-access=free}}</ref><ref>{{cite journal|last1=Demaster|first1=D.|last2=Trites|first2=A.|last3=Clapham|first3=P.|last4=Mizroch|first4=S.|last5=Wade|first5=P. |last6=Small|first6=R.|last7=Hoef|first7=J.|title=The sequential megafaunal collapse hypothesis: Testing with existing data |journal=Progress in Oceanography|year=2006|doi=10.1016/j.pocean.2006.02.007|volume=68|issue=2–4|pages=329–342 |bibcode=2006PrOce..68..329D}}</ref><ref>{{cite journal|last1=Estes|first1=J. A.|last2=Doak|first2=D. F.|last3=Springer|first3=A. M.|last4=Williams|first4=T. M.|title=Causes and consequences of marine mammal population declines in southwest Alaska: a food-web perspective|journal=Philosophical Transactions of the Royal Society B: Biological Sciences|volume=364|pages=1647–1658|year=2009|doi=10.1098/rstb.2008.0231|issue=1524|pmid=19451116|pmc=2685424}}</ref> Orcas have been observed preying on [[Terrestrial animal|terrestrial mammals]], such as [[moose]] swimming between islands off the northwest coast of North America.{{sfn|Baird|2002|p=23}}<ref name="BairdBaird2006">{{cite book|first1=Robert W.|last1=Baird|first2=Robin W.|last2=Baird|title=Killer Whales of the World: Natural History and Conservation|url=https://books.google.com/books?id=Rjksm-5-ap4C&pg=PA23|access-date=February 2, 2011|date=August 31, 2006|publisher=Voyageur Press|isbn=978-0-7603-2654-1|pages=23–|archive-url=https://web.archive.org/web/20110721191653/http://books.google.com/books?id=Rjksm-5-ap4C&pg=PA23|archive-date=July 21, 2011|url-status=live}}</ref> Orca [[cannibalism (zoology)|cannibalism]] has also been reported based on analysis of stomach contents, but this is likely to be the result of scavenging remains dumped by whalers.{{sfn|Baird|2002|p=124}} One orca was also attacked by its companions after being shot.<ref name="Jefferson et al. 1991"/> Although resident orcas have never been observed to eat other marine mammals, they occasionally harass and kill porpoises and seals for no apparent reason.{{sfn|Ford|Ellis|Balcomb|2000|p=19}} Some dolphins recognize resident orcas as harmless and remain in the same area.<ref>{{cite web |last1=Chung |first1=Emily |title=Killer whales eat dolphins. So why are these dolphins tempting fate? |url=https://www.cbc.ca/news/science/pacific-white-sided-dolphins-southern-resident-killer-whales-1.5021585 |publisher=[[CBC News]] |date=2019-02-18 |access-date=August 7, 2023 |archive-date=August 7, 2023 |archive-url=https://web.archive.org/web/20230807195251/https://www.cbc.ca/news/science/pacific-white-sided-dolphins-southern-resident-killer-whales-1.5021585 |url-status=live }}</ref>

Orcas do consume [[seabird]]s but are more likely to kill and leave them uneaten. [[Penguin]] species recorded as prey in Antarctic and sub-Antarctic waters include [[gentoo penguin]]s, [[chinstrap penguin]]s, [[king penguin]]s and [[rockhopper penguin]]s.<ref>{{cite journal|last1=Pitman|first1=R. L.|last2=Durban|first2=J. W.|year=2010|title=Killer whale predation on penguins in Antarctica|journal=Polar Biology|volume=33|issue=11|pages=1589–1594|doi=10.1007/s00300-010-0853-5|bibcode=2010PoBio..33.1589P |s2cid=44055219 }}</ref> Orcas in many areas may prey on [[cormorant]]s and [[gull]]s.{{sfn|Baird|2002|p=14}} A captive orca at [[Marineland of Canada]] discovered it could regurgitate fish onto the surface, attracting sea gulls, and then eat the birds. Four others then learned to copy the behaviour.<ref>{{Cite news |agency=Associated Press |url=http://news.mongabay.com/2005/0907-ap.html |title=Whale uses fish as bait to catch seagulls then shares strategy with fellow orcas |date=September 7, 2005 |access-date=February 18, 2010 |archive-date=March 22, 2010 |archive-url=https://web.archive.org/web/20100322204614/http://news.mongabay.com/2005/0907-ap.html |url-status=live }}</ref>