Editing Predation (section)

===Search===

Predators have a choice of search modes ranging from ''sit-and-wait'' to ''active'' or ''widely foraging''.<ref name=Bell4>{{harvnb|Bell|2012|pages=4–5}}</ref><ref name=Kramer2001/><ref>{{cite book |last1=Eastman |first1=Lucas B. |last2=Thiel |first2=Martin |contribution=Foraging behavior of crustacean predators and scavengers |editor-last1=Thiel |editor-first1=Martin |editor-last2=Watling |editor-first2=Les |title=Lifestyles and feeding biology |date=2015 |publisher=Oxford University Press |isbn=9780199797066 |pages=535–556}}</ref><ref>{{cite journal |last1=Perry |first1=Gad |title=The Evolution of Search Modes: Ecological versus Phylogenetic Perspectives |journal=The American Naturalist |date=January 1999 |volume=153 |issue=1 |pages=98–109 |doi=10.1086/303145|pmid=29578765 |bibcode=1999ANat..153...98P |s2cid=4334462 }}</ref> The sit-and-wait method is most suitable if the prey are dense and mobile, and the predator has low energy requirements.<ref name=Bell4/> Wide foraging expends more energy, and is used when prey is sedentary or sparsely distributed.<ref name=Pianka/><ref name=Bell4/> There is a continuum of search modes with intervals between periods of movement ranging from seconds to months. Sharks, [[Molidae|sunfish]], [[Insectivorous]] birds and [[shrew]]s are almost always moving while web-building spiders, aquatic invertebrates, praying mantises and [[kestrel]]s rarely move. In between, [[plover]]s and other [[shorebirds]], freshwater fish including [[crappie]]s, and the larvae of [[Coccinellidae|coccinellid beetles (ladybirds)]], alternate between actively searching and scanning the environment.<ref name=Bell4/>

[[File:Thalassarche melanophrys in flight 2 - SE Tasmania.jpg|thumb|left|The [[black-browed albatross]] regularly flies hundreds of kilometres across the nearly empty ocean to find patches of food.]]

Prey distributions are often clumped, and predators respond by looking for ''patches'' where prey is dense and then searching within patches.<ref name=Kramer2001/> Where food is found in patches, such as rare shoals of fish in a nearly empty ocean, the search stage requires the predator to travel for a substantial time, and to expend a significant amount of energy, to locate each food patch.<ref name=Bell2012/> For example, the [[black-browed albatross]] regularly makes foraging flights to a range of around {{convert|700|km|mi|abbr=off|-1}}, up to a maximum foraging range of {{convert|3000|km|mi|abbr=off|-1}} for breeding birds gathering food for their young.{{efn|A range of 3000 kilometres means a flight distance of at least 6000 kilometres out and back.}}<ref name="Gremillet2000">{{cite journal |last1=Gremillet |first1=D. |last2=Wilson |first2=R. P. |last3=Wanless |first3=S. |last4=Chater |first4=T. |title=Black-browed albatrosses, international fisheries and the Patagonian Shelf |journal=Marine Ecology Progress Series |date=2000 |volume=195 |pages=69–280|doi=10.3354/meps195269 |bibcode=2000MEPS..195..269G |doi-access=free }}</ref> With static prey, some predators can learn suitable patch locations and return to them at intervals to feed.<ref name=Bell2012>{{harvnb|Bell|2012|pages=69–188}}</ref> The [[optimal foraging theory|optimal foraging]] strategy for search has been modelled using the [[marginal value theorem]].<ref name="Charnov1976">{{cite journal |last=Charnov |first=Eric L. |title=Optimal foraging, the marginal value theorem |journal=Theoretical Population Biology |volume=9 |issue=2 |year=1976 |doi=10.1016/0040-5809(76)90040-x |pmid=1273796 |pages=129–136 |bibcode=1976TPBio...9..129C }}</ref>

Search patterns often appear random. One such is the [[Lévy flight|Lévy walk]], that tends to involve clusters of short steps with occasional long steps. It is a [[Lévy flight foraging hypothesis|good fit to the behaviour]] of a wide variety of organisms including bacteria, honeybees, sharks and human hunter-gatherers.<ref>{{cite journal |last1=Reynolds |first1=Andy |title=Liberating Lévy walk research from the shackles of optimal foraging |journal=Physics of Life Reviews |date=September 2015 |volume=14 |pages=59–83 |doi=10.1016/j.plrev.2015.03.002 |pmid=25835600 |bibcode=2015PhLRv..14...59R }}</ref><ref>{{cite journal |last1=Buchanan |first1=Mark |title=Ecological modelling: The mathematical mirror to animal nature |journal=Nature |date=5 June 2008 |volume=453 |issue=7196 |pages=714–716 |doi=10.1038/453714a |pmid=18528368 |doi-access=free }}</ref>