The animals were able to wait it out

Mar 18, 2009 08:20 GMT  ·  By

The last Ice Age, when glaciers advanced through much of Europe, was not very kind to the Irish wildlife, as much of it was completely annihilated and never recovered. However, it seems that a brave little frog species managed to endure, and toughed out the extremely cold weather. At the same time, members of the same species, located in mainland England, failed to do so, and while some were killed, other retreated further to the South. The brave frogs are the only ones to inhabit the Emerald Isle.

Zoological Society of London (ZSL) investigator Amber Teacher, who has been the scientist conducting the new research, says that the common Rana temporaria frog repopulated Britain as it returned from mainland Europe, some 10,000 years ago.

However, the Irish variety succeeded in enduring in certain specific spots of the island, where temperatures seem to have registered some anomalies and allowed the amphibians to live. All around the creatures, everything was frozen to death, and only a small region of their former habitat was suited for sustaining life.

The main thing that hints at this conclusion is the huge difference that researchers have noted between the English and the Irish varieties of the same animals. While on the outside they may look roughly the same, they are pretty different on the inside, as far as their genetic structure goes. The find is detailed in the January 21st issue of the scientific journal Heredity. Researchers from Queen Mary, University of London, have also contributed to the new study.

“It appears that some frogs may have survived through the glaciations in this ice-free part of Ireland, as there is a distinct genetic lineage found in the South of Ireland that is not found elsewhere in Europe. So within Ireland, we can find frogs that originate from this small part of southern Ireland, mixed with the frogs that came from Western Europe to repopulate the British Isles after the ice age retreated,” the ZSL researcher adds.

As far as amphibians go, Ireland is not a very rich country, as it only houses one species of native lizards. It also has no land snakes or turtles, and the only animals that can be found in abundance are foxes, badgers and rabbits, which roam the countryside in “hoards.”