Editing Common frog (section)

==Habitat and distribution==
Outside the breeding season, common frogs live a solitary life in damp [[wetland]] [[ecological niche|niche]]s near ponds or marshes or among long [[riparian]] grass.<ref name="Roots">{{cite book |author=Roots, Clive |title=Hibernation |publisher=Greenwood Press |location=Westport, Conn |year=2006 |pages=510, 511 |isbn=0-313-33544-3}}</ref> They are normally active for much of the year, only [[hibernating]] in the coldest months.<ref name="Amphibia"/> In the most northern extremities of their range they may be trapped under ice for up to nine months of the year, but recent studies have shown that in these conditions they may be relatively active at temperatures close to freezing.<ref name="Roots"/> In the [[British Isles]], common frogs typically hibernate from late October to January. They will re-emerge as early as February if conditions are favorable, and migrate to bodies of water such as garden ponds to spawn.<ref name="enfo">{{cite web |title=The Common Frog – (''Rana temporaria'') |work=enfo.ie |publisher=ENFO |url=http://www.enfo.ie/leaflets/bs33.htm |access-date=2007-08-09 |url-status=dead |archive-date=28 September 2007 |archive-url=https://web.archive.org/web/20070928111934/http://www.enfo.ie/leaflets/bs33.htm}}</ref> Where conditions are harsher, such as in the [[Alps]], they emerge as late as early June. Common frogs hibernate in running waters, muddy burrows, or in layers of decaying leaves and mud at the bottom of ponds or lakes primarily with a current. The oxygen uptake through the skin suffices to sustain the needs of the cold and motionless frogs during hibernation.<ref name="BBC"/><ref name="Amphibia">{{cite web|url=https://amphibiaweb.org/cgi-bin/amphib_query?where-genus=Rana&where-species=temporaria |access-date=2007-08-09|last=Kuzmin|first=Sergius L.|date=10 November 1999|title=''Rana temporia'' |publisher=AmphibiaWeb}}</ref><ref>{{Cite web|title=Common Frog final|last=Dunlop|first=David|date=26 February 2004|publisher=Lancashire BAP|url=http://www.lbap.org.uk/bap/urban/Microsoft%20Word%20-%20Common%20Frog%20final.pdf|access-date=2007-08-09|archive-date=27 September 2007|archive-url=https://web.archive.org/web/20070927161321/http://www.lbap.org.uk/bap/urban/Microsoft%20Word%20-%20Common%20Frog%20final.pdf|url-status=dead}}</ref>

Common frogs are found throughout much of Europe as far north as northern Scandinavia inside the [[Arctic Circle]] and as far east as the [[Urals]], except for most of the [[Iberian Peninsula|Iberia]], southern Italy, and the southern [[Balkans]]. Other areas where the common frog has been introduced include the [[Isle of Lewis]], Shetland, [[Orkney]] and the [[Faroe Islands]]. It is also found in Asia, and eastward to Japan.<ref name="BBC"/><ref>[http://jenskjeld.info/UK_side/indexuk.htm ''Rana temporaria'' have established themselves as a wild population in Nólsoy]. jenskjeld.info</ref>

The common frog has long been thought to be an entirely introduced species in Ireland,<ref name="enfo"/> however, genetic analyses suggest that particular populations in the south west of Ireland are indeed indigenous to the country.<ref name=IrlFrog1/> The authors propose that the Irish frog population is a mixed group that includes native frogs that survived the [[last glacial period]] in ice free [[refugium (population biology)|refugia]], natural post-glacial colonizers and recent artificial introductions from Western Europe.<ref name=IrlFrog1>{{cite journal|issn=0018-067X|volume=102|issue=5|pages=490–496|last=Teacher|first=A. G. F.|author2=T. W. J. Garner |author3=R. A. Nichols |title=European phylogeography of the common frog (''Rana temporaria''): routes of postglacial colonization into the British Isles, and evidence for an Irish glacial refugium|journal=[[Heredity (journal)|Heredity]] |date=21 January 2009|doi=10.1038/hdy.2008.133|pmid=19156165|doi-access=free}}</ref><ref>{{cite web |url=http://www.zsl.org/science/news/irish-frogs-may-have-survived-ice-age,568,NS.html|title=Irish frogs may have survived Ice Age|publisher=[[Zoological Society of London]]|date=17 March 2009|url-status=dead |archive-url=https://web.archive.org/web/20090618224252/http://www.zsl.org/science/news/irish-frogs-may-have-survived-ice-age,568,NS.html|archive-date=18 June 2009}}</ref>

=== Genetic population structure ===
The common frog is a very widely distributed species, being common all throughout Europe and northwest Asia. The more peripheral subpopulations of common frogs are significantly less in number, as well as less genetically variable. There is a steep genetic decline when approaching the periphery of the common frog's distribution range.<ref name=Johansson>{{cite journal |last1=Johansson |first1=Markus |last2=Primmer |first2=Craig R. |last3=Merilä |first3=Juha |date=14 March 2006 |title=History vs. current demography: explaining the genetic population structure of the common frog (''Rana temporaria'') |doi=10.1111/j.1365-294X.2006.02866.x |journal=Molecular Ecology |volume=15 |issue=4 |pages=975–983 |pmid=16599961 |bibcode=2006MolEc..15..975J |s2cid=30974911 |ref=Demography}}</ref> Additionally, genetic differentiation of common frog subpopulations tends to decrease in relation to increasing latitude.<ref name=Johansson/> The colder climates create a strong selective pressure favoring common frog populations able to behaviorally [[Thermoregulation|thermoregulate]] at a high degree.<ref name="Ludwig-2015" />