Editing Kea (section)

==Behaviour==
===Breeding===
At least one observer has reported that the kea is [[polygynous]], with one male attached to multiple females. The same source also noted that there was a surplus of females.<ref>{{cite journal | last1 = Jackson | first1 = J. R. | year = 1962 | title = The life of the Kea | journal = Canterbury Mountaineer | volume = 31 | pages = 120–123}}</ref>

Kea are social and live in groups of up to 13 birds.<ref name="Clark70">{{cite journal | last1 = Clark | first1 = C.M.H. | year = 1970 | title = ''Observations on population, movements and food of the kea, ''Nestor notabilis | url = http://notornis.osnz.org.nz/system/files/Notornis_17_2.pdf | journal = Notornis | volume = 17 | pages = 105–114 | access-date = 29 September 2011 | archive-date = 24 November 2020 | archive-url = https://web.archive.org/web/20201124125659/http://notornis.osnz.org.nz/system/files/Notornis_17_2.pdf | url-status = dead }}</ref> Isolated individuals do badly in captivity, but respond well to seeing themselves in a mirror.<ref>{{cite web |url= http://www.biosci.unl.edu/avcog/research/articles/Mirror.pdf |title= Note on the lasting responsiveness of a kea ''Nestor notabilis'' toward its mirror image |first1= J. |last1= Diamond |first2= A. |last2= Bond |year= 1989 |work= Avicultural Magazine 95(2) |pages= 92–94 |archive-url= https://web.archive.org/web/20111002104838/http://www.biosci.unl.edu/avcog/research/articles/Mirror.pdf |archive-date= 2 October 2011 |url-status=dead}}</ref>

[[File:Kea (Nestor notabilis) 7 Wochen (1).JPG|thumb|right|Kea chick, [[Weltvogelpark Walsrode]], [[Germany]]]]
In one study, nest sites occur at a density of one per {{convert|4.4|sqkm|sqmi}}.<ref name = "Elliott99">{{citation |first1= G. |last1=Elliott |first2= J. |last2= Kemp |year= 1999 |title= Conservation ecology of kea (''Nestor notabilis'') |publisher=WWF New Zealand}}</ref> The breeding areas are most commonly in [[southern beech]] (''Nothofagus'') forests, located on steep mountainsides. Breeding at heights of {{convert|1600|m|ft}} above sea level and higher, it is one of the few parrot species in the world to regularly spend time above the [[tree line]]. Nest sites are usually positioned on the ground underneath large beech trees, in rock crevices, or dug burrows between roots. They are accessed by tunnels leading back {{convert|1|to|6|m|ft}} into a larger chamber, which is furnished with lichens, moss, ferns, and rotting wood. The laying period starts in July and reaches into January.<ref>{{cite journal|last1=Jackson |first1=J. R. |year=1960 |title=Keas at Arthur's Pass |url=http://notornis.osnz.org.nz/system/files/Notornis_09-1960/Notornis_9_2.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://notornis.osnz.org.nz/system/files/Notornis_09-1960/Notornis_9_2.pdf |archive-date=2022-10-09 |url-status=live |journal=Notornis |volume=9 |pages=39–58}} {{dead link|date=May 2017 |bot=InternetArchiveBot |fix-attempted=yes}}</ref> Two to five white eggs are laid, with an incubation time of around 21 days, and a brooding period of 94 days.<ref name="FST66">{{citation |first1= RA |last1= Falla |first2= RB |last2= Sibson |first3= EG |last3= Turbot |year= 1966 |title= A Field guide to the birds of New Zealand |publisher=Collins, London |isbn= 0-00-212022-4}}</ref>

Mortality is high among young kea, with less than 40% surviving their first year.<ref name="KCT">{{cite web|author=Akers, Kate|author2=Orr-Walker, Tamsin|name-list-style=amp|url=http://www.keaconservation.co.nz/pdfs/kct_factsheet_april09.pdf|title=Kea Factsheet|publisher=Kea Conservation Trust|date=April 2009|archive-url=https://web.archive.org/web/20100602100348/http://www.keaconservation.co.nz/pdfs/kct_factsheet_april09.pdf|archive-date=2 June 2010}}</ref> The [[median]] lifespan of a wild subadult kea has been estimated at five years, based on the proportion of kea seen again in successive seasons in Arthur's Pass, and allowing for some emigration to surrounding areas. Around 10% of the local kea population were expected to be over 20 years of age.<ref name="BondDiamond1992"/> The oldest known captive kea was 50 years old in 2008.<ref name="KCT"/>

===Cognitive abilities===
Kea parrots have strong cognitive abilities. According to recent studies, Kea share the ability to have sense of impulsive control and planning forward. Kea can wait up to 160 seconds for a more preferred reward. In addition, Kea also use trial and error tactics and use observational learning to solve difficult problems and when tasked with puzzles and locks. These abilities of decision-making are similar to primates and other intelligent bird species like the African grey parrot.<ref>{{cite journal | url=https://doi.org/10.1037/com0000086 | doi=10.1037/com0000086 | title=Kea (Nestor notabilis) decide early when to wait in food exchange task | date=2017 | last1=Schwing | first1=Raoul | last2=Weber | first2=Stefan | last3=Bugnyar | first3=Thomas | journal=Journal of Comparative Psychology | volume=131 | issue=4 | pages=269–276 | pmid=28857604 | url-access=subscription }}</ref><ref>{{cite journal | url=https://doi.org/10.1007/s10071-010-0342-9 | doi=10.1007/s10071-010-0342-9 | title=How do keas (Nestor notabilis) solve artificial-fruit problems with multiple locks? | date=2011 | last1=Miyata | first1=Hiromitsu | last2=Gajdon | first2=Gyula K. | last3=Huber | first3=Ludwig | last4=Fujita | first4=Kazuo | journal=Animal Cognition | volume=14 | issue=1 | pages=45–58 | pmid=20640911 | url-access=subscription }}</ref>

===Diet and feeding===
An omnivore, the kea feeds on more than 40 plant species, beetle larvae, grasshoppers, land snails, other birds (including [[Shearwater|shearwater chicks]]), and mammals (including sheep, rabbits and mice).<ref name="nhnz"/><ref name="Clark70"/><ref name=adw>[https://animaldiversity.org/accounts/Nestor_notabilis/ Nestor notabilis kea] Animal Diversity</ref> It has been observed breaking open shearwater nests to feed on the chicks after hearing the chicks in their nests.<ref>Christina Troup. [http://www.teara.govt.nz/en/birds-of-open-country/3/2 Birds of open country – kea digging out a shearwater chick] {{Webarchive|url=https://web.archive.org/web/20121017225136/http://www.teara.govt.nz/en/birds-of-open-country/3/2 |date=17 October 2012}}, ''Te Ara – the Encyclopedia of New Zealand'', Ministry of Culture and Heritage. Updated 20 November 2009. Accessed 22 January 2010.</ref> It enjoys the flesh and bone marrow from carcasses.<ref name=adw/> The kea has also taken advantage of human garbage and "gifts" of food.<ref>{{cite journal | last1 = Gajdon | first1 = G.K. | last2 = Fijn | first2 = N. | last3 = Huber | first3 = L. | year = 2006 | title = Limited spread of innovation in a wild parrot, the kea (''Nestor notabilis'') | journal = Animal Cognition | volume = 9 | issue = 3| pages = 173–181 | doi = 10.1007/s10071-006-0018-7| pmid = 16568276 | s2cid = 994622 }}</ref>

[[Tool use by animals|Tool use behaviour]] has been observed in this species, wherein a bird named Bruce, who has a broken upper beak, wedged pebbles between his tongue and lower mandible and then utilised this arrangement to aid with his [[preening]] habits.<ref name="kindy">{{cite web |last1=Kindy |first1=David |title=Bruce the Parrot Uses Tools to Survive Despite a Broken Beak |url=https://www.smithsonianmag.com/smart-news/bruce-the-parrot-uses-tools-to-survive-180978645/ |publisher=Smithsonian Magazine |access-date=19 September 2021}}</ref>

====Sheep====
[[File:Sheep killed by kea (cropped).jpg|thumb|Sheep, suspected to have been killed by kea in July 1907]]
The controversy about whether the kea preys on sheep is long-running. Sheep suffering from unusual wounds on their sides or loins were noticed by the mid-1860s, within a decade of sheep farmers moving into the high country. Although some supposed the cause was a new disease, suspicion soon fell on the kea. James MacDonald, head shepherd at Wanaka Station, witnessed a kea attacking a sheep in 1868, and similar accounts were widespread.<ref name="Benham">{{cite journal | last1 = Benham | first1 = W. B. | year = 1906 | title = Notes on the Flesh-eating Propensity of the Kea (''Nestor notabilis'') | url = http://rsnz.natlib.govt.nz/volume/rsnz_39/rsnz_39_00_001080.html | journal = Transactions of the Royal Society of New Zealand | volume = 39 | pages = 71–89}}</ref> Prominent members of the scientific community accepted that kea attacked sheep, with [[Alfred Russel Wallace|Alfred Wallace]] citing this as an example of behavioural change in his 1889 book ''[[Darwinism (book)|Darwinism]]''.<ref>{{cite book |last=Wallace |first=Alfred |date=1889 |title=Darwinism |url=https://en.wikisource.org/wiki/Page%3ADarwinism_by_Alfred_Wallace_1889.djvu/97 |location=London |publisher=Macmillan and Co |page=75 |author-link=Alfred Russel Wallace}}</ref> [[Thomas Potts (naturalist)|Thomas Potts]] noted that attacks were most frequent during winter and snow-bound sheep with two years growth in their fleece were the most vulnerable, while newly-shorn sheep in warm weather were rarely molested.<ref>{{cite book |last=Potts |first=Thomas |date=1882 |orig-year=from "Out in the Open," 1882 |publication-date=1895 |title=The New Zealand Reader |url=http://nzetc.victoria.ac.nz/tm/scholarly/tei-ReeNewZ-t1-front-d2-d1.html |chapter=The Kea, or Mountain Parrot |chapter-url=http://nzetc.victoria.ac.nz/tm/scholarly/tei-ReeNewZ-t1-body-d13.html |editor-last=Reeves |editor-first=William Pember (Minister of Education) |editor-link=William Pember Reeves |location=Wellington |publisher=Samuel Costall, Government Printer |pages=81–90 |author-link=Thomas Potts (naturalist) |via=New Zealand Electronic Text Collection (NZETC)}}</ref>

Despite substantial anecdotal evidence of sheep attacks,<ref name="Benham" /><ref name="Marriner06" /> others remained unconvinced, especially in later years. For instance, in 1962, animal specialist J.R. Jackson concluded that while the bird may attack sick or injured sheep, especially if it mistakes them for dead, it is not a significant predator.<ref>{{cite journal | last1 = Jackson | first1 = J.R. | year = 1962 | title = Do kea attack sheep? | url = http://notornis.osnz.org.nz/system/files/Notornis_10_1.pdf | journal = Notornis | volume = 10 | pages = 33–38 | access-date = 29 September 2011 | archive-date = 18 February 2021 | archive-url = https://web.archive.org/web/20210218204509/https://www.notornis.osnz.org.nz/system/files/Notornis_10_1.pdf | url-status = dead }}</ref> In August 1992, however, its nocturnal assaults were captured on video,<ref name="nhnz" /><ref name="Temple1994">{{cite magazine |last=Temple |first=Philip |date=1994 |issue=24 |title=Kea: the feisty parrot |url=https://www.nzgeo.com/stories/kea-the-feisty-parrot/ |magazine=New Zealand Geographic |location=Auckland  |publication-date=Oct–Dec 1994|access-date=2019-01-13}}</ref> proving that at least some kea will attack and feed on healthy sheep. The video confirmed what many scientists had long suspected: that the kea uses its powerful, curved beak and claws to rip through the layer of wool and eat the fat from the back of the animal. Though the bird does not directly kill the sheep, death can result from infections or accidents suffered by animals when trying to escape.

Since kea are now a protected species, their depredations are generally tolerated by sheep farmers, though why some kea attack sheep, and others do not, remains unclear. Various theories, including similarities with existing food sources, curiosity, entertainment, hunger, maggots as well as a progression from scavenging dead sheep and hides have all been put forward as to how the behaviour was first acquired.<ref name="Marriner06"/><ref name="Temple1994"/> [[Anecdotal]] evidence also suggests that only particular birds have learned the behaviour, with identification and removal of those individuals being sufficient to control the problem.<ref name="Temple1994"/><ref name=":0" />

There are also anecdotal reports of kea attacking rabbits, dogs, and even horses.<ref name="Marriner06"/> There are also suggestions that kea used to feed on [[moa]] in a similar way.<ref name="Temple1994"/>