Editing Orca (section)

===Intelligence===
{{Main|Cetacean intelligence}}
Orcas have the second-heaviest brains among marine mammals<ref name=spear>{{cite news|last=Spear|first= Kevin|url=https://www.orlandosentinel.com/2010/03/06/killer-whales-how-smart-are-they/ |title=Killer whales: How smart are they?|archive-url=https://web.archive.org/web/20150908001401/http://articles.orlandosentinel.com/2010-03-06/news/os-seaworld-killer-whale-brains-20100302_1_killer-whales-orcas-dolphin-or-porpoise |archive-date=September 8, 2015 |work=Orlando Sentinel|date= March 7, 2010|url-status=live|access-date= March 7, 2010}}</ref> (after [[sperm whale]]s, which have the largest brain of any animal).<ref>{{Cite news|last=Dunham|first=Will|date=2017-10-16|title=Big and brilliant: complex whale behavior tied to brain size|language=en|work=Reuters|url=https://www.reuters.com/article/us-science-whales-idUSKBN1CL30I|access-date=2020-12-23|archive-date=July 19, 2021|archive-url=https://web.archive.org/web/20210719045118/https://www.reuters.com/article/us-science-whales-idUSKBN1CL30I|url-status=live}}</ref> Orcas have more [[grey matter|gray matter]] and more cortical neurons than any mammal, including humans.<ref>{{Cite journal |last1=Ridgway |first1=Sam H. |last2=Brownson |first2=Robert H. |last3=Van Alstyne |first3=Kaitlin R. |last4=Hauser |first4=Robert A. |date=2019-12-16 |editor-last=Li |editor-first=Songhai |title=Higher neuron densities in the cerebral cortex and larger cerebellums may limit dive times of delphinids compared to deep-diving toothed whales |journal=PLOS ONE |language=en |volume=14 |issue=12 |pages=e0226206 |doi=10.1371/journal.pone.0226206 |issn=1932-6203 |pmc=6914331 |pmid=31841529 |bibcode=2019PLoSO..1426206R |doi-access=free }}</ref> They can be [[Animal training|trained]] in captivity and are often described as intelligent,<ref name=cbs2010/>{{sfn|Carwardine|2001|p=67}} although defining and measuring "intelligence" is difficult in a species whose environment and behavioural strategies are very different from those of humans.{{sfn|Carwardine|2001|p=67}} Orcas imitate others, and seem to deliberately teach skills to their kin. Off the [[Crozet Islands]], mothers push their calves onto the beach, waiting to pull the youngster back if needed.{{sfn|Heimlich|Boran|2001|p=45}}{{sfn|Baird|2002|pp=61–62}} In March 2023, a female orca was spotted with a newborn [[pilot whale]] in [[Snæfellsnes]].<ref>{{cite news | url=https://www.theguardian.com/environment/2023/mar/10/killer-whale-orca-adopts-abducts-pilot-whale-calf-aoe | title='Extraordinary' sighting of orca with baby pilot whale astounds scientists | newspaper=The Guardian | date=March 10, 2023 | last1=Weston | first1=Phoebe }}</ref>

[[File:Orca with iceball cropped.JPG|thumb|An orca plays with a ball of ice, soon after a researcher threw a snowball at the whale.]]
People who have interacted closely with orcas offer numerous [[Anecdotal evidence|anecdotes]] demonstrating the whales' curiosity, playfulness, and ability to solve problems. Alaskan orcas have not only learned how to steal fish from [[Longline fishing|longlines]], but have also overcome a variety of techniques designed to stop them, such as the use of unbaited lines as decoys.{{sfn|Obee|Ellis|1992|p=42}} Once, fishermen placed their boats several miles apart, taking turns retrieving small amounts of their catch, in the hope that the whales would not have enough time to move between boats to steal the catch as it was being retrieved. The tactic worked initially, but the orcas adapted quickly and split into groups.{{sfn|Obee|Ellis|1992|p=42}}

In other anecdotes, researchers describe incidents in which wild orcas playfully tease humans by repeatedly moving objects the humans are trying to reach,<ref name=BF>{{Cite journal |year=2005 |title=Killer whale games |journal=Blackfish Sounder |volume=13 |page=5 |url=http://www.killerwhale.org/BFS/BFS_13.pdf |archive-url=https://web.archive.org/web/20071011062137/http://www.killerwhale.org/BFS/BFS_13.pdf |archive-date=October 11, 2007 |url-status=dead}}</ref> or suddenly start to toss around a chunk of ice after a human throws a snowball.<ref>Pitman, Robert L. [http://www.livescience.com/animals/090206-nhm-killer-whale-snowball.html Scientist Has 'Snowball Fight' With a Killer Whale] {{Webarchive|url=https://web.archive.org/web/20200915041640/https://www.livescience.com/3284-scientist-snowball-fight-killer-whale.html |date=September 15, 2020 }}. ''Live Science'', February 6, 2009. Retrieved March 7, 2010</ref>

The orca's use of dialects and the passing of other learned behaviours from generation to generation have been described as a form of [[animal culture]].<ref>{{Cite journal |doi=10.1371/journal.pbio.0050139 |last=Marino |first=Lori |title=Cetaceans Have Complex Brains for Complex Cognition |journal=[[PLOS Biology]] |year=2007 |page=e139 |volume=5 |issue=e139 |pmid=17503965 |pmc=1868071 |display-authors=etal |doi-access=free }}</ref>

{{blockquote|The complex and stable vocal and behavioural cultures of [[Sympatry|sympatric]] groups of killer whales (''Orcinus orca'') appear to have no parallel outside humans and represent an independent evolution of cultural faculties.<ref name=rendell>{{cite journal|last1=Rendell|first1= Luke|first2=Hal|last2= Whitehead|url=http://whitelab.biology.dal.ca/lr/bbs.htm|title=Culture in whales and dolphins|journal=Behavioral and Brain Sciences|year=2001|volume=24|issue=2|pages=309–324|access-date=March 7, 2010|pmid=11530544|doi=10.1017/S0140525X0100396X|s2cid=24052064|archive-date=May 30, 2010|archive-url=https://web.archive.org/web/20100530054246/http://whitelab.biology.dal.ca/lr/bbs.htm|url-status=live}}</ref>}}