British species migrate northward
BBCNews.com, Sept. 7, 2006
Right across Britain, animals are on the march, moving northwards and going to higher ground as the climate warms, experts have told a major conference.
The scientists have studied how the ranges of more than 300 species - from small mammals to insects - have changed over the past 25 years.
About 80% of them have extended the northern margin of their domains, with an average shift of 30-60km.
Researchers outlined their findings at the BA Festival of Science in Norwich.
Chris Thomas from the University of York said the changes fitted neatly with the predictions of climate models.
"Species are moving north, they're climbing mountains, they're retreating at their southern boundaries," the professor added.
"To me, 80% is an incredibly high percentage of species, given all the other changes we've made to our landscape over the past 25-50 years. It's amazing how strong already the signature of climate change is."
Professor Thomas was detailing the analysis here at the British Association's Science Festival.
The UK has extensive records for the distribution of a wide range of animals, probably the richest data sets in the world.
The study, performed by a number of scientists including Chris Thomas under the leadership of Rachael Hickling from the Centre for Ecology and Hydrology, looked at 16 different groups of vertebrates and invertebrates.
Species covered ranged from dragonflies and spiders through to birds and mammals.
As well as the northward migration, some 70% of species shifted the elevations at which they commonly live, climbing on average by between five and 10 metres per decade.
Of the groups studied, only three species of amphibians and reptiles significantly moved south and to lower ground.
"It's becoming clear that the vast majority of species are behaving in similar ways. They are doing so in quite different taxonomic groups and in quite different parts of the world - essentially all parts of the world," said Professor Thomas.
A new mix
The York scientist said there was still great uncertainty as to how individual species would fare as the global climate continued to warm; but the prospects for many were not good, he argued.
Some would benefit from the higher temperatures and changes in vegetation that this would bring; others would struggle as their habitats were overtaken.
"Some 'cold-adapted northerner' species might be perfectly happy with a warmer climate until the 'heat-loving southerners' arrive and displace them," he said.
"Global temperatures and CO2 levels are expected to be higher than those experienced for millions of years, such that few of the individual species that currently exist, and none of the combinations of species we currently possess, will have experienced such conditions previously."
The results of the range change analysis were recently published in the journal Global Change Biology.