Editing Handicap principle (section)

=== Signals to other species ===

{{further|Anti-predator adaptation}}

[[File:Stotting gazelle.jpg|thumb|Impala [[stotting]], a behavior that may serve as a [[pursuit deterrence]] signal to predators.<ref name="Caro"/>|alt=Photo of an impala jumping high in the African bush]]

Signals may be directed at [[Predation|predators]], with the function of showing that pursuit will probably be unprofitable. [[Stotting]], for instance, is a form of energetic jumping that certain [[Gazelle|gazelles]] do when they sight a predator. As this behavior gives no evident benefit and would seem to waste resources (diminishing the gazelle's head start if chased by the predator), it appeared likely to be selected against. However, it made sense when seen as a [[pursuit deterrence]] signal to predators. By investing a little energy to show a lion that it has the fitness necessary to avoid capture, a gazelle reduces the likelihood that it will have to evade the lion in an actual pursuit. The lion, faced with the demonstration of fitness, might decide that it would fail to catch this gazelle, and thus choose to avoid a probably wasted pursuit. The benefit to the gazelle is twofold. First, for the small amount of energy invested in the stotting, the gazelle might not have to expend the tremendous energy required to evade the lion. Second, if the lion is in fact capable of catching this gazelle, the gazelle's bluff may lead to its survival that day (in the event the bluff succeeds).<ref name="Caro">{{cite journal |last=Caro |first=Tim M. |author-link=Tim Caro |title=The functions of stotting in Thomson's gazelles: Some tests of the predictions |journal=Animal Behaviour |year=1986 |volume=34 |issue=3 |pages=663–684 |doi=10.1016/S0003-3472(86)80052-5 |s2cid=53155678 }}</ref> However, the mathematical biologist [[John Maynard Smith]] commented that [[Stotting#Possible explanations|other explanations were possible]], such as that it was an honest signal of fitness,<ref name="Maynard Smith 2003 p61"/> or an honest signal that the predator had been detected,<ref>{{cite journal |last1=FitzGibbon |first1=C. D. |last2=Fanshawe |first2=J. H. |title=Stotting in Thomson's gazelles: an honest signal of condition |journal=Behavioral Ecology and Sociobiology |date=August 1988 |volume=23 |issue=2 |pages=69–74 |doi=10.1007/bf00299889 |bibcode=1988BEcoS..23...69F |s2cid=2809268 }}</ref> and it was hard to see how stotting could be a handicap.<ref name="Maynard Smith 2003 p61">{{cite book |last1=Maynard Smith |first1=John |author1-link=John Maynard Smith |last2=Harper |first2=David |title=Animal Signals |publisher=Oxford University Press |year=2003 |pages=61–63 |isbn=978-0-19-852685-8 |url=https://books.google.com/books?id=SUA51MeG1lcC&pg=PA61}}</ref>

Another example is provided by [[lark]]s, some of which discourage [[merlin (bird)|merlins]] by sending a similar message: they [[Bird vocalization|sing]] while being chased, telling their predator that they will be difficult to capture.<ref>{{cite journal |last=Cresswell |first=Will |title=Song as a pursuit-deterrent signal, and its occurrence relative to other anti-predation behaviours of skylark (Alauda arvensis) on attack by merlins (Falco columbarius) |journal=Behavioral Ecology and Sociobiology |date=March 1994 |volume=34 |issue=3 |pages=217–223 |doi=10.1007/BF00167747 |bibcode=1994BEcoS..34..217C |s2cid=25608814}}</ref>