Editing Signalling theory (section)

==Dishonest signals==

[[File:Uca lactea-male-600-450.jpg|thumb|left|Male [[fiddler crab]], in the family Ocypodidae, signals with its enlarged fighting claw, but weak regrown claws may be dishonest signals.]]

Because there are both mutual and conflicting interests in most animal signalling systems, a central problem in signalling theory is dishonesty or [[cheating (biology)|cheating]]. For example, if foraging birds are safer when they give a warning call, cheats could give false alarms at random, just in case a predator is nearby. But too much cheating could cause the signalling system to collapse. Every dishonest signal weakens the integrity of the signalling system, and so reduces the fitness of the group.{{sfn|Dawkins|Krebs|1978}} An example of dishonest signalling comes from Fiddler crabs such as ''[[Austruca mjoebergi]]'', which have been shown to bluff (no conscious intention being implied) about their fighting ability. When a claw is lost, a crab occasionally regrows a weaker claw that nevertheless intimidates crabs with smaller but stronger claws.{{sfn|Lailvaux|Reaney|Backwell|2009}} The proportion of dishonest signals is low enough for it not to be worthwhile for crabs to test the honesty of every signal through combat.{{sfn|Dawkins|Krebs|1978}}

[[Richard Dawkins]] and [[John Krebs]] in 1978 considered whether individuals of the same species would act as if attempting to deceive each other. They applied a "[[gene-centered view of evolution|selfish gene]]" view of evolution to animals' [[deimatic behaviour|threat displays]] to see if it would be in their genes' interests to give dishonest signals. They criticised previous [[ethology|ethologists]], such as [[Nikolaas Tinbergen]] and [[Desmond Morris]], for suggesting that such displays were "[[Group selection|for the good of the species]]". They argued that such communication ought to be viewed as an [[evolutionary arms race]] in which signallers evolve to become better at manipulating receivers, while receivers evolve to become more resistant to manipulation.{{sfn|Dawkins|Krebs|1978}} The game theoretical model of the [[War of attrition (game)|war of attrition]] similarly suggests that threat displays ought not to convey any reliable information about intentions.{{sfn|Caryl|1979}}

Deceptive signals can be used both within and between species. Perhaps the best-known example of inter-species deception is [[mimicry]]: when individuals of one species mimic the appearance or behaviour of individuals of another species. A variety of mimicry types exist, including Batesian, Müllerian,<ref>{{Citation |last1=Cardé |first1=Ring T. |title=Apterygota |date=2009 |url=http://dx.doi.org/10.1016/b978-0-12-374144-8.00011-4 |encyclopedia=Encyclopedia of Insects |pages=38 |publisher=Elsevier |access-date=2023-01-21 |last2=Resh |first2=Vincent H.|doi=10.1016/b978-0-12-374144-8.00011-4 |isbn=9780123741448 |url-access=subscription }}</ref> host mimicry<ref>{{Cite journal |last1=Hauber |first1=Mark E. |last2=Kilner |first2=Rebecca M. |date=2006-11-21 |title=Coevolution, communication, and host chick mimicry in parasitic finches: who mimics whom? |url=http://dx.doi.org/10.1007/s00265-006-0291-0 |journal=Behavioral Ecology and Sociobiology |volume=61 |issue=4 |pages=497–503 |doi=10.1007/s00265-006-0291-0 |s2cid=44030487 |issn=0340-5443|url-access=subscription }}</ref> and "aggressive" mimicry.<ref>{{Cite journal |last1=Marshall |first1=David C. |last2=Hill |first2=Kathy B. R. |date=2009-01-14 |title=Versatile Aggressive Mimicry of Cicadas by an Australian Predatory Katydid |journal=PLOS ONE |volume=4 |issue=1 |pages=e4185 |doi=10.1371/journal.pone.0004185 |pmid=19142230 |pmc=2615208 |bibcode=2009PLoSO...4.4185M |issn=1932-6203|doi-access=free }}</ref> A very frequent type is [[ant mimicry]].<ref>{{Cite journal |last1=Akino |first1=T. |last2=Knapp |first2=J. J. |last3=Thomas |first3=J. A. |last4=Elmes |first4=G. W. |date=1999-07-22 |title=Chemical mimicry and host specificity in the butterfly Maculinea rebeli, a social parasite of Myrmica ant colonies |url=http://dx.doi.org/10.1098/rspb.1999.0796 |journal=Proceedings of the Royal Society of London. Series B: Biological Sciences |volume=266 |issue=1427 |pages=1419–1426 |doi=10.1098/rspb.1999.0796 |pmc=1690087 |issn=0962-8452}}</ref> Deception within species can be bluffing (during contest)<ref>{{Cite journal |last1=Adams |first1=Eldrige S. |last2=Caldwell |first2=Roy L. |date=April 1990 |title=Deceptive communication in asymmetric fights of the stomatopod crustacean Gonodactylus bredini |url=http://dx.doi.org/10.1016/s0003-3472(05)80382-3 |journal=Animal Behaviour |volume=39 |issue=4 |pages=706–716 |doi=10.1016/s0003-3472(05)80382-3 |s2cid=53187553 |issn=0003-3472|url-access=subscription }}</ref><ref>{{Cite journal |last1=Backwell |first1=Patricia R. Y. |last2=Christy |first2=John H. |last3=Telford |first3=Steven R. |last4=Jennions |first4=Michael D. |last5=Passmore |first5=Jennions |date=2000-04-07 |title=Dishonest signalling in a fiddler crab |url=http://dx.doi.org/10.1098/rspb.2000.1062 |journal=Proceedings of the Royal Society of London. Series B: Biological Sciences |volume=267 |issue=1444 |pages=719–724 |doi=10.1098/rspb.2000.1062 |pmid=10821619 |pmc=1690591 |issn=0962-8452}}</ref> or sexual mimicry<ref>{{Cite journal |last=Robertson |first=Hugh M. |date=August 1985 |title=Female dimorphism and mating behaviour in a damselfly, Ischnura ramburi: females mimicking males |url=http://dx.doi.org/10.1016/s0003-3472(85)80013-0 |journal=Animal Behaviour |volume=33 |issue=3 |pages=805–809 |doi=10.1016/s0003-3472(85)80013-0 |s2cid=53154990 |issn=0003-3472|url-access=subscription }}</ref> where males or females mimic the patterns and behaviour of the opposite sex. A famous example is the bluegill sunfish<ref>{{Cite journal |last=Dominey |first=Wallace J. |date=April 1980 |title=Female mimicry in male bluegill sunfish—a genetic polymorphism? |url=http://dx.doi.org/10.1038/284546a0 |journal=Nature |volume=284 |issue=5756 |pages=546–548 |doi=10.1038/284546a0 |bibcode=1980Natur.284..546D |s2cid=4276618 |issn=0028-0836|url-access=subscription }}</ref><ref>{{Cite journal |last1=Gross |first1=Mart R. |last2=Charnov |first2=Eric L. |date=November 1980 |title=Alternative male life histories in bluegill sunfish |journal=Proceedings of the National Academy of Sciences |volume=77 |issue=11 |pages=6937–6940 |doi=10.1073/pnas.77.11.6937 |pmid=16592922 |pmc=350407 |bibcode=1980PNAS...77.6937G |issn=0027-8424|doi-access=free }}</ref> where mimic males look like and behave like females to sneak into the guarded nests of territorial males in order to fertilize some of the eggs.