Editing Ecology (section)

=== Behavioural ecology ===
{{Main|Behavioural ecology}}
[[File:Chameleon spectra.jpg|left|upright=1.6|thumb|Social display and colour variation in differently adapted species of [[chameleons]] (''Bradypodion'' spp.). Chameleons change their skin colour to match their background as a behavioural defence mechanism and also use colour to communicate with other members of their species, such as dominant (left) versus submissive (right) patterns shown in the three species (A-C) above.<ref name="Stuart-Fox08"/>]]

All organisms can exhibit behaviours. Even plants express complex behaviour, including memory and communication.<ref name="Karban08"/> Behavioural ecology is the study of an organism's behaviour in its environment and its ecological and evolutionary implications. Ethology is the study of observable movement or behaviour in animals. This could include investigations of motile [[sperm]] of plants, mobile [[phytoplankton]], [[zooplankton]] swimming toward the female egg, the cultivation of fungi by [[weevils]], the mating dance of a [[salamander]], or social gatherings of [[amoeba]].<ref name="Tinbergen63"/><ref name="Hamner85"/><ref name="Strassmann00"/><ref name="Sakurai85"/><ref name="Anderson61"/>

Adaptation is the central unifying concept in behavioural ecology.<ref>{{cite web|url=http://www.behavecol.com/pages/society/welcome.html |title=Behavioral Ecology |publisher=International Society for Behavioral Ecology |access-date=15 April 2011 |archive-url=https://web.archive.org/web/20110410105207/http://www.behavecol.com/pages/society/welcome.html |archive-date=10 April 2011}}</ref> Behaviours can be recorded as traits and inherited in much the same way that eye and hair colour can. Behaviours can evolve by means of natural selection as adaptive traits conferring functional utilities that increases reproductive fitness.<ref name="Gould82"/><ref name="Wilson00"/>

[[File:Common jassid nymphs and ants02.jpg|thumb|upright|'''Mutualism:''' [[Leafhopper]]s (''Eurymela fenestrata'') are protected by [[meat ant|ants]] (''Iridomyrmex purpureus'') in a [[Mutualism (biology)|mutualistic]] relationship. The ants protect the leafhoppers from predators and stimulate feeding in the leafhoppers, and in return, the leafhoppers feeding on plants exude honeydew from their anus that provides energy and nutrients to tending ants.<ref name="Eastwood04"/>]]

Predator-prey interactions are an introductory concept into food-web studies as well as behavioural ecology.<ref name="Ives04"/> Prey species can exhibit different kinds of behavioural adaptations to predators, such as avoid, flee, or defend. Many prey species are faced with multiple predators that differ in the degree of danger posed. To be adapted to their environment and face predatory threats, organisms must balance their energy budgets as they invest in different aspects of their life history, such as growth, feeding, mating, socializing, or modifying their habitat. 

Hypotheses posited in behavioural ecology are generally based on adaptive principles of conservation, optimization, or efficiency.<ref name="Begon05"/><ref name="Allee49"/><ref name="Krebs93"/> For example, "[t]he threat-sensitive predator avoidance hypothesis predicts that prey should assess the degree of threat posed by different predators and match their behaviour according to current levels of risk"<ref name="Webb10"/> or "[t]he optimal [[Escape distance|flight initiation distance]] occurs where expected postencounter fitness is maximized, which depends on the prey's initial fitness, benefits obtainable by not fleeing, energetic escape costs, and expected fitness loss due to predation risk."<ref name="Cooper10"/>

Elaborate sexual [[display (zoology)|displays]] and posturing are encountered in the behavioural ecology of animals. The [[birds-of-paradise]], for example, sing and display elaborate ornaments during [[courtship]]. These displays serve a dual purpose of signalling healthy or well-adapted individuals and desirable genes. The displays are driven by [[sexual selection]] as an advertisement of quality of traits among [[suitors]].<ref name="Kodric-Brown84"/>