Editing Frog (section)

===Call===
{{See also|Sexual selection in frogs}}
[[File:Dendropsophus microcephalus - calling male (Cope, 1886).jpg|thumb|A male ''[[Dendropsophus microcephalus]]'' displaying its vocal sac during its call]]
[[File:Atelopus franciscus male territorial call - pone.0022080.s002.oga|thumb|Advertisement call of male ''[[Atelopus franciscus]]'']]

The call or croak of a frog is unique to its species. Frogs create this sound by passing air through the [[larynx]] in the throat. In most calling frogs, the sound is amplified by one or more vocal sacs, membranes of skin under the throat or on the corner of the mouth, that distend during the amplification of the call. Some frog calls are so loud that they can be heard up to a mile (1.6{{nbsp}}km) away.<ref>{{cite web |url=http://www.dnr.state.oh.us/Home/species_a_to_z/SpeciesGuideIndex/bullfrog/tabid/6576/Default.aspx |title=Bullfrog |publisher=Ohio Department of Natural Resources |access-date=June 19, 2012 |archive-date=August 18, 2012 |archive-url=https://web.archive.org/web/20120818105255/http://www.dnr.state.oh.us/Home/species_a_to_z/SpeciesGuideIndex/bullfrog/tabid/6576/Default.aspx |url-status=dead }}</ref> Additionally, some species have been found to use man-made structures such as drain pipes for artificial amplification of their call.<ref>{{Cite journal|last1=Tan|first1=W.-H.|last2=Tsai|first2=C.-G.|last3=Lin|first3=C.|last4=Lin|first4=Y. K.|date=June 5, 2014|title=Urban canyon effect: storm drains enhance call characteristics of the Mientien tree frog|journal=Journal of Zoology|language=en|volume=294|issue=2|pages=77–84|doi=10.1111/jzo.12154|issn=0952-8369|url=http://ntur.lib.ntu.edu.tw//handle/246246/260607}}</ref> The [[Ascaphus truei|coastal tailed frog]] (''Ascaphus truei'') lives in mountain streams in North America and does not vocalise.<ref>{{cite web |url=http://www.californiaherps.com/frogs/pages/a.truei.html |title=''Ascaphus truei'': Coastal Tailed Frog |author=Nafis, Gary |year=2012  |publisher=California Herps |access-date=June 19, 2012}}</ref>

The main function of calling is for male frogs to attract mates. Males may call individually or there may be a chorus of sound where numerous males have converged on breeding sites. In many frog species, such as the [[Common Tree Frog|common tree frog]] (''Polypedates leucomystax''), females reply to males' calls, which acts to reinforce reproductive activity in a breeding colony.<ref>{{cite journal| last=Roy| first=Debjani| year=1997| title=Communication signals and sexual selection in amphibians| journal=Current Science| volume=72| pages=923–927| url=http://www.ias.ac.in/jarch/currsci/72/00000944.pdf| url-status=dead| archive-url=https://web.archive.org/web/20120923071112/http://www.ias.ac.in/jarch/currsci/72/00000944.pdf| archive-date=September 23, 2012}}</ref> Female frogs prefer males that produce sounds of greater intensity and lower frequency, attributes that stand out in a crowd. The rationale for this is thought to be that by demonstrating his prowess, the male shows his fitness to produce superior offspring.<ref>{{cite journal |author=Gerhardt, H. C. |year=1994 |title=The evolution of vocalization in frogs and toads |journal=Annual Review of Ecology and Systematics |volume=25 |issue=1 |pages=293–324 |doi=10.1146/annurev.es.25.110194.001453 |bibcode=1994AnRES..25..293G }}</ref>

A different call is emitted by a male frog or unreceptive female when mounted by another male. This is a distinct chirruping sound and is accompanied by a vibration of the body.<ref name=Badger3>{{cite book |title=Frogs |last=Badger |first=David |author2=Netherton, John |year=1995 |publisher=Airlife Publishing Ltd |isbn=978-1-85310-740-5 |pages=39–44 }}</ref> Tree frogs and some non-aquatic species have a rain call that they make on the basis of humidity cues prior to a shower.<ref name=Badger3/> Many species also have a territorial call that is used to drive away other males. All of these calls are emitted with the mouth of the frog closed.<ref name=Badger3/> A distress call, emitted by some frogs when they are in danger, is produced with the mouth open resulting in a higher-pitched call. It is typically used when the frog has been grabbed by a predator and may serve to distract or disorient the attacker so that it releases the frog.<ref name=Badger3/>

[[file:Banded_Bull_Frog_Call.ogg|left|thumb|Distinctive low "jug-o-rum" sound of [[banded bullfrog]]]]

Many species of frog have deep calls. The croak of the [[American bullfrog]] (''Rana catesbiana'') is sometimes written as "jug o' rum".<ref>{{cite book|last=Hilton|first=Bill Jr.|chapter=9. 'Jug-o-Rum': Call of the Amorous Bullfrog |title=The Piedmont Naturalist, Volume 1 |publisher=Hilton Pond Center for Piedmont Natural History |location=York, SC |year=1986 |isbn=978-0-9832151-0-3}}</ref> The [[Pacific Tree Frog|Pacific tree frog]] (''Pseudacris regilla'') produces the [[onomatopoeia|onomatopoeic]] "ribbit" often heard in films.<ref>{{cite web |url=http://www.beachwatchers.wsu.edu/island/essays/TreeFrogs.htm |title=The RRRRRRRRiveting Life of Tree Frogs |last=Nash |first=Pat |date=February 2005 |access-date=August 4, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120309105032/http://www.beachwatchers.wsu.edu/island/essays/TreeFrogs.htm |archive-date=March 9, 2012 }}</ref> Other renderings of frog calls into speech include "brekekekex koax koax", the call of the marsh frog (''[[Pelophylax ridibundus]]'') in ''The Frogs'', an Ancient Greek comic drama by [[Aristophanes]].<ref>{{cite web |url=http://records.viu.ca/~johnstoi/aristophanes/frogs.htm |title=The Frogs |author=Aristophanes |access-date=June 19, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120513143510/http://records.viu.ca/~johnstoi/aristophanes/frogs.htm |archive-date=May 13, 2012 }}</ref> The calls of the [[Concave-eared torrent frog]] (''Amolops tormotus'') are unusual in many aspects. The males are notable for their varieties of calls where upward and downward frequency modulations take place. When they communicate, they produce calls that fall in the [[ultrasound]] frequency range. The last aspect that makes this species of frog's calls unusual is that nonlinear acoustic phenomena are important components in their acoustic signals.<ref name="ultrasonic">{{cite journal|author1=Suthers, R.A.|author2=Narins, P.M.|author3=Lin, W|author4=Schnitzler, H|author5=Denzinger, A|author6=Xu, C|author7=Feng, A.S.|year=2006|title= Voices of the dead: complex nonlinear vocal signals from the larynx of an ultrasonic frog|journal=Journal of Experimental Biology|volume=209|issue=24|pages=4984–4993| doi= 10.1242/jeb.02594|pmid=17142687|doi-access=free|bibcode=2006JExpB.209.4984S }}</ref>