Editing Golden eagle (section)

=== Territoriality ===
[[File:BK1D0090.jpg|thumb|right|Two golden eagles in an aerial conflict over their home ranges, the upper bird clearly a juvenile.]]
Territoriality is believed to be the primary cause of interactions and confrontations between non-paired golden eagles. Golden eagles maintain some of the largest known home ranges (or territories) of any bird species but there is much variation of home range size across the range, possibly dictated by food abundance and habitat preference. Home ranges in most of the range can vary from {{convert|20|to|200|km2|sqmi|abbr=on}}.<ref>{{cite journal|author=McGrady, M.J.|year=1997|title=Golden Eagle|journal= BWP Update|volume= 1|pages= 99–114}}</ref> In [[San Diego County]] in [[California]], the home ranges varied from {{convert|49|to|137|km2|sqmi|abbr=on}}, with an average of {{convert|93|km2|sqmi|abbr=on}}.<ref>{{cite journal|author=Dixon, J.B. |s2cid=88449730 |title=The Golden Eagle in San Diego County, California |journal=Condor |volume=39 |issue=2 |pages=49–58 |year=1937 |jstor=1363773 |doi=10.2307/1363773}}</ref> However, some home ranges have been much smaller, such as in southwestern Idaho where, possibly due to an abundance of jackrabbits, home ranges as small as {{convert|4.85|km2|sqmi|abbr=on}} are maintained.<ref name=marz/> The smallest known home ranges on record for golden eagles are in the Bale Mountains of Ethiopia, where they range from {{convert|1.5|to|9|km2|sqmi|abbr=on}}.<ref name= Clouet>{{cite journal|author=Clouet, M.|author2= Barrau, C.|author3= Goar, J.L. |title=The Golden Eagle (''Aquila chrysaetos'') in the Bale Mountains, Ethiopia |journal=Journal of Raptor Research |volume=33 |issue=2 |pages=102–9 |year=1999 |url=https://sora.unm.edu/sites/default/files/journals/jrr/v033n02/p00102-p00109.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://sora.unm.edu/sites/default/files/journals/jrr/v033n02/p00102-p00109.pdf |archive-date=2022-10-09 |url-status=live}}</ref> 46% of undulating displays in Montana occurred shortly after the juvenile eagles left their parents range, suggesting that some residents defend and maintain territories year-round.<ref>{{cite journal |author=Harmata, A. R. |title=What is the function of undulating flight display in Golden Eagles? |journal=Raptor Research |volume=16 |issue=4 |pages=103–9 |year=1982 |url=https://sora.unm.edu/sites/default/files/journals/jrr/v016n04/p00103-p00109.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://sora.unm.edu/sites/default/files/journals/jrr/v016n04/p00103-p00109.pdf |archive-date=2022-10-09 |url-status=live}}</ref> Elsewhere it is stated that home ranges are less strictly maintained during winter but hunting grounds are basically exclusive.<ref name= Watson/> In Israel and Scotland, aggressive encounters peaked from winter until just before egg-laying and were less common during the nesting season.<ref name= Watson/><ref name= Bahat>Bahat, O. (1989). Aspects in the ecology and biodynamics of the Golden Eagle (''Aquila chrysaetos homeyeri'') in the arid regions of Israel. Master's Thesis. Tel Aviv Univ. Tel Aviv, Israel.</ref> Threat displays include undulating flight and aggressive direct flapping flight with exaggerated downstrokes.<ref name= Ellis2>{{cite book |author=Ellis, D.H. |title=Development of behaviour in the Golden Eagle |publisher=Wiley |year=1979 |jstor=3830587 |series=Wildlife Monographs |volume=70 |issue=70 |pages=3–94}}</ref> Most displays by mature golden eagles (67% for males and 76% for females) occur, rather than around the nest, at the edge of their home ranges.<ref name= Collopy2/> In Western Norway, most recorded undulating flight displays occur during the pre-laying period in late winter/early spring.<ref name= Gunnar/> Display flights seem to be triggered by the presence of other golden eagles.<ref name= Watson/> The use of display flights has a clear benefit in that it lessens the need for physical confrontations, which can be fatal.<ref name= Collopy2/> Usually, non-breeding birds are treated aggressively by the golden eagle maintaining their home range, normally being chased to the apparent limit of the range but with no actual physical contact.<ref name= Watson/> The territorial flight of the adult golden eagle is sometimes preceded or followed by intense bouts of undulating displays. The invader often responds by rolling over and presenting talons to the aggressor. Rarely, the two eagles will lock talons and tumble through the air; sometimes fall several revolutions and in some cases even tumble to the ground before releasing their grip.<ref name= Gunnar/><ref>{{cite journal |author=Haller, H. |title=Spatial organization and dynamics of a population of Golden Eagles (''Aquila chrysaetos'') in the central Alps |journal=Ornithol. Beob. |volume=79 |pages=163–211 |year=1982 |issn=0030-5707 |oclc=689312112}}</ref> In some parts of the Alps, the golden eagle population has reached the saturation point in appropriate habitat and apparently violent confrontations are more common than in other parts of the range.<ref>Haller, H. 1996. ''The Golden Eagle in the Grisons: Long-term studies on the population ecology of ''Aquila chrysaetos'' in the centre of the Alps''. Ornithol. Beob. Beiheft 9:1–167.</ref> Golden eagles may express their aggression via body language while perched, typically the adult female when confronted by an intruding eagle: the head and body are upright, feathers on head and neck are erect; the wings may be slightly spread and beak open; often accompanied by intense gaze. They then often engage in a similar posture with wings spread wide and oriented toward the threat; sometimes rocking back on tail and even flopping over onto the back with talons extended upward as defense. Such behavior may be accompanied by wing slap against the threatening intruder.<ref name= Ellis2/> When approached by an intruder, the defending eagle turns away, partially spreads tail, lowers head, and remains still; adults on the nest may lower head and "freeze" when approached by a person or a helicopter.<ref name= Ellis2/> Females in Israel displayed more than males and mostly against interspecific intruders; males apparently displayed primarily as part of courtship.<ref name= Bahat/> Five of 7 aggressive encounters at carcasses during winter in Norway were won by females; in 15 of 21 conflicts, the younger bird dominated an older conspecific.<ref name= Halley>{{cite journal |author=Halley, D.J.|author2= Gjershaug, J.O. |title=Inter- and intra-specific dominance relationships and feeding behaviour of golden eagles ''Aquila chrysaetos'' and Sea Eagles ''Haliaeetus albicilla'' at carcass |journal=Ibis |volume=140 |issue=2 |pages=295–301 |year=1998 |doi=10.1111/j.1474-919X.1998.tb04392.x }}</ref> However, obvious juvenile eagles (apparent to the adult eagles due to the amount of white on their wings and tail) are sometimes allowed to penetrate deeply into a pair's home range and all parties commonly ignore each other.<ref name= Kochert>Kochert, M.N. (1972). ''Population status and chemical contamination in Golden Eagles in southwestern Idaho''. Masters in Science thesis. University of Idaho, Moscow.</ref><ref>{{cite journal |last1=Brown |first1=L.H. |first2=A. |last2=Watson |title=The Golden Eagle in relation to its food supply |journal=Ibis |volume=106 |issue=1 |pages=78–100 |year=1964 |doi=10.1111/j.1474-919X.1964.tb03682.x }}</ref> In [[North Dakota]], it was verified that parent eagles were not aggressive towards their own young after the nesting period and some juveniles stayed on their parents territory until their 2nd spring and then left by their own accord.<ref name="O'Toole">{{cite journal |author1=O'Toole, L.T. |author2=Kennedy, P.L. |author3=Knight, R.L. |author4=McEwen, L.C. |title=Postfledging behavior of Golden Eagles |journal=Wilson Bulletin |volume=111 |issue=4 |pages=472–7 |year=1999 |url=https://sora.unm.edu/sites/default/files/journals/wilson/v111n04/p0472-p0477.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://sora.unm.edu/sites/default/files/journals/wilson/v111n04/p0472-p0477.pdf |archive-date=2022-10-09 |url-status=live}}</ref>