Editing Northern pike (section)

===Aggression===
The northern pike is a relatively aggressive species, especially with regard to feeding. For example, when food sources are scarce, [[Cannibalism (zoology)|cannibalism]] develops, starting around five weeks in a small percentage of populations.<ref name="onlinelibrary.wiley.com">{{cite journal | last1 = Giles | first1 = N. | last2 = Wright | first2 = R. M. | last3 = Nord | first3 = M. E. | year = 1986 | title = Cannibalism in pike fry, ''Esox lucius'' L.: some experiments with fry densities | journal = Journal of Fish Biology | volume = 29 | issue = 1 | pages = 107–113 | doi = 10.1111/j.1095-8649.1986.tb04930.x | bibcode = 1986JFBio..29..107G }}</ref> This cannibalism occurs when the ratio of predator to prey is two to one.<ref name="onlinelibrary.wiley.com"/> One can expect this because when food is scarce, Northern pike fight for survival, such as turning on smaller pike to feed; this is seen in other species such as [[tiger salamander]]s. Usually, pike tend to feed on smaller fish, such as the [[banded killifish]]. However, when pike exceed {{convert|700|mm|in|abbr=on}} long, they feed on larger fish.<ref name="Mann, R. H. K. 1976">{{cite journal| last1 = Mann | first1 = R. H. K. | year = 1976 | title = Observations on the age, growth, reproduction and food of the pike ''Esox lucius'' (L.) in two rivers in southern England | journal = Journal of Fish Biology | volume = 8 | issue = 2| pages = 179–197 | doi = 10.1111/j.1095-8649.1976.tb03930.x| bibcode = 1976JFBio...8..179M }}</ref>

Because of cannibalism when food is short, pike suffer a fairly high young mortality rate.<ref name="jstor.org">{{cite journal| first=R. H. K.| last=Mann| title=The Annual Food Consumption and Prey Preferences of Pike (''Esox lucius'') in the River Frome, Dorset| journal=Journal of Animal Ecology| volume=51| issue=1| date=February 1982| pages=81–95| jstor=4312| doi=10.2307/4312| bibcode=1982JAnEc..51...81M}}</ref> Cannibalism is more prevalent in cool summers, as the upcoming pike have slow growth rates in that season and might not be able to reach a size to deter the larger pike. Cannibalism is likely to arise in low growth and low food conditions.<ref name="jstor.org"/> Pike do not discriminate siblings well,{{citation needed|date=July 2018}} so cannibalism between siblings is likely.

Aggression also arises from a need for space.<ref name="Reproduction, Early Life 1967 pp. 651-693">{{cite journal| title=A Study of Reproduction, Early Life, Weight-Length Relationship and Growth of Pike, ''Esox lucius'' L., in Windermere| first1=Winifred E.| last1=Frost |first2=Charlotte |last2=Kipling| author-link2=Charlotte Kipling| journal=Journal of Animal Ecology| volume=36| issue=3| date=October 1967| pages=651–693| jstor=2820| doi=10.2307/2820| bibcode=1967JAnEc..36..651F}}</ref> Young pike tend to have their food stolen by larger pike.<ref name="Reproduction, Early Life 1967 pp. 651-693"/> Pike are aggressive if not given enough space because they are territorial.<ref name="sciencedirect.com">{{cite journal| first=Peter| last=Eklov| title=Group foraging versus solitary foraging efficiency in piscivorous predators: The perch, ''Perca fluviatilis'', and pike, ''Esox lucius'', patterns| journal=Animal Behaviour| date=August 1992| pages=313–326| volume=44| issue=2| doi=10.1016/0003-3472(92)90037-a| s2cid=53196955}}</ref> They use a form of foraging known as ambush foraging. Unlike species such as [[perch]], pike undergo bursts of energy instead of actively chasing down prey. As such, a fair amount of inactive time occurs until they find prey. Hunting efficiency decreases with competition;<ref name="sciencedirect.com"/> the larger the pike, the larger the area controlled by that particular pike. An inverse relation to vegetation density and pike size exists, which is due to the possibility of cannibalism from the largest pike.<ref name="nrcresearchpress.com">{{cite journal| first=P.| last=Eklov| title=Effects of Habitat complexity and prey abundance on the spatial and temporal distributions of perch and pike| date=9 April 2011| journal=Canadian Journal of Fisheries and Aquatic Sciences| volume=54| issue=7| pages=1520–1531| doi=10.1139/f97-059| url=http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88671}}</ref> This makes sense, as the smaller pike need more vegetation to avoid being eaten. Large pike do not have this worry and can afford the advantage of a large line of sight. They prefer a tree structure habitat.<ref name="nrcresearchpress.com"/>

There has been at least one instance of a pike attacking a dog.<ref>Dan Bross, [https://alaskapublic.org/2022/10/21/programmed-to-eat-northern-pike-mauls-husky-at-north-pole-gravel-pit ‘Programmed to eat’: Northern pike mauls husky at North Pole gravel pit]. ''Alaska Public Media'', 21 October 2022, Retrieved 26 October 2022</ref>

Pike are occasionally preyed upon by otters.<ref>Mark Cocker, [https://www.theguardian.com/environment/2013/may/12/claxton-norfolk-pike-huge-otter 'The pike was huge, but not huge enough to fight off an otter']. ''The Guardian'', 12 May 2013. Retrieved 2 May 2022</ref>