Scott, Amundsen, Shackleton, Laurila, Patrelle and Herczeg – what do these people have in common? Facial hair? Ability to endure prolonged psychological torture of cross-country skiing in a flat, shapeless landscape? Not so – as far as I know. But all of them have made great contributions to scientific advances in matters relating to our understanding of hardship of life in polar regions. Most recently, Patrelle et al (2012) – in a article published in Polar Biology – reveal that subarctic common frogs (Rana temporaria) live up to ages of 18 years or even beyond.
The remarkable longevity of frogs in Northern Scandinavia relates to the reduced pace of life in north – being able to be active only fraction of the year, the frogs in north take longer to mature than their conspecifics in south. Due to their lower per year mortality rates – either due to shorter activity period per se (lowered physiological costs), or due to reduced predation risk (or both) – the northern frogs also live about 4-5 times longer than their conspecifics in south.
Interesting is also the difference between sexes: males mature earlier than females, and their growth rates wind down soon after that. Females continue and even speed up their yearly growth rates the older they get. Read more from pages of Polar Biology.
Patrelle C, MB Hjernquist, A Laurila, F Söderman & J Merilä (2012) Sex differences in age structure, growth rate and body size of common frogs Rana temporaria in the subarctic. Polar Biology, in press.