Southern species driven north by climate change

British birds, animals and insects are moving northwards in response to climate change, new research has revealed.

A study led by scientists at the University of York has shown how birds, butterflies, other insects and spiders have colonised nature reserves and areas protected for wildlife, as they move north in response to changing environmental conditions.

The study, covering more than 250 species, was led by researchers in the Department of Biology at York, and its conclusions were based on the analysis of millions of records of wildlife submitted predominantly by members of the public.

Many species need to spread towards the poles, where conditions remain cool enough for them to survive climate warming. However, doing this is complicated because many landscapes across the world are dominated by human agriculture and development, which form barriers to the movement of species.

The mainstay of traditional conservation has been to establish protected areas and nature reserves to provide refuges against the loss of habitats and other threats in the surrounding countryside.

The new research shows protected areas are the places that most animal species colonise as they spread into new regions.

Lead author Professor Chris Thomas, of the University of York, said: “Protected areas are like stepping stones across the landscape, allowing species to set up a succession of new breeding populations as they move northwards.”

Co-author Dr Phillipa Gillingham, now a lecturer at Bournemouth University, calculated that species were on average about four times more likely to colonise nature reserves than might be expected.

She said: “For the seven focal species of birds and butterflies that we studied in greatest 
detail, 40 per cent of new colonisations occurred in the mere 8.4 per cent of the land that was 
protected.

“Similar patterns were observed among more than 250 invertebrate species.”

But the study showed that species vary greatly in how much they need reserves.

Dr David Roy, of the Natural Environment Research Council’s Centre for Ecology and Hydrology, said: “Some species, such as the Dartford warbler and silver-spotted skipper butterfly, are largely confined to nature 
reserves, whereas others, like the nightjar and stone curlew, are less dependent on these sites.”

Dr Richard Bradbury, of the RSPB, said: “Sites of importance for wildlife stand out like beacons in otherwise impoverished landscapes.

“This study shows that the hugely important role they play now will continue undiminished in the future. Protecting these arks, as well as restoring and recreating new ones where we can, will provide the vital network enabling more species to survive the spectre of climate change.”

James Pearce-Higgins, of the British Trust for Ornithology, said the study is a great example of how volunteer recorders and national monitoring schemes provide the information to answer key conservation questions of global importance, such as how we can help wildlife cope with climate change.

“Only through the dedicated effort of so many people can we undertake the scale of long-term monitoring required.”

The findings were published online by the Proceedings of the National Academy of Sciences of the United States.