Is body size of the water frog Rana esculenta complex responding to climate change?
- 307 Downloads
Recent studies on climate responses in ectothermic (cold-blooded) vertebrates have been few in number and focussed on phenology rather than morphology. According to Bergmann’s rule, endothermic (warm-blooded) vertebrates from cooler climates tend to be larger than congeners from warmer regions. Although amphibians are ectothermic vertebrates, weather and climatic conditions may also impact on their morphology, and thereby affect their survival rates and population dynamics. In this paper, we show, in a unique long-term study during the period 1963–2003 in an agricultural landscape in western Poland, that the body length of two water frog parental species (males of both Rana ridibunda and R. lessonae) increased significantly. However, their hybridogenetic hybrid R. esculenta did not show similar changes. A significant relationship with a large-scale climatic factor, the winter North Atlantic Oscillation index, was found positive for R. ridibunda males and R. lessonae females, and negative for R. esculenta females. Our findings, the first for amphibians, are consistent with other studies reporting that recent climate change has affected the morphology of animals. However, we also show that changes in amphibian phenotype linked to climate may vary independently between (even very similar) species.
- Berger L (1966) Biometrical studies on the population of green frogs from the environs of Poznañ. Ann Zool 23:303–324Google Scholar
- Berger L (1973a) Sexual maturity of males within forms of Rana esculenta complex. Zool Pol 22:177–188Google Scholar
- Berger L, Rybacki M (1998) Composition and ecology of water frog populations in agricultural landscape in Wielkopolska (central Poland). Biol Bull Pozn 35:103–111Google Scholar
- Gotthard K (2001) Growth strategies of ectothermic animals in temperate environments. In: Atkinson D, Thorndyke M (eds) Animal developmental ecology. BIOS Scientific Publishers, Oxford, pp 287–304Google Scholar
- Laugen AT, Laurila A, Jönsson KI, Söderman F, Merilä J (2005) Do common frogs (Rana temporaria) follow Bergmann’s rule? Evol Ecol Res 7:717–731Google Scholar
- Møller AP, Merilä J (2004) Analysis and interpretation of long-term studies investigating responses to climate change. Adv Ecol Res 35:111–130Google Scholar
- Rybacki M, Berger L (1994) Distribution and ecology of water frogs in Poland. Zool Pol 39:293–303Google Scholar
- Schmidt-Nielsen K (1984) Scaling: why is animal size so important. Cambridge University Press, Cambridge, NYGoogle Scholar
- Tryjanowski P, Rybacki M, Sparks T (2003) Changes in the first spawning dates of common frogs and common toads in western Poland in 1978–2002. Ann Zool Fenn 40:459–464Google Scholar
- Uzzel T, Günther R, Berger L (1977) Rana ridibunda and Rana esculenta: a leaky hybridogenetic system (Amphibia, Salientia). Proc Acad Nat Sci Philadelphia 128:147–171Google Scholar