Despite their name, tawny owls actually come in two colours. And in Finland, the freezing, snowy winters give pale grey birds acamouflage advantage over their darker brown-featheredcounterparts. But as the Finnish winters get milder, the grey owls are disappearing.
The lead researcher, Dr Patrik Karell, said that this showed that the birds were evolving in response to climate change, so the tawny owlgene pool is actually getting browner. This is the first evidence of climate change having such an effect in the animal kingdom.
The University of Helsinki team gathered 30 years' worth of genetic and population data on tawny owls. They found that the birds inherited their plumage colour from their parents. The grey tawnys, as well being better hidden from predators in the snow, seem to be endowed with other genetic advantages that make them healthier and stronger. But despite this, the brown owl population is now overtaking that of the greys, because the warmer winters have improved the brown owls' chances of survival.
发表于 2011-6-26 16:26
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发表于 2011-7-11 18:44
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