Rare southern species of birds are on the increase in the UK as a result of climatic change, a study has revealed.

Researchers at Durham, the RSPB and Cambridge University have found that birds such as the cirl bunting and Dartford warbler are becoming more common across a wide range of habitats in Britain as temperatures rise.

Unfortunately, some northern species, such as the fieldfare and redwing, are not faring quite so well and their numbers are falling, the study warned.

The researchers looked at twenty-five year population trends of 42 bird species in relation to changes in climatic suitability simulated using climatic envelope models.

Professor Brian Huntley, from Durham University, said: "The results are what we expected to find given the changes in climate over the last 20 years.

"Because the UK is in the middle Latitudes of Europe, we expected that recent climatic warming would favour species with ranges located in the south of Europe and adversely affect northern species."

Northern species that are under threat also include the Slavonian grebe, a bird whose range extends at its southern margins to Scotland.

The fieldfare and redwing - birds that are familiar as winter visitors to bird tables and gardens in the north-east but that breed only locally in parts of Scotland - are also suffering a downturn in numbers.

The models used to explore these trends are the same models that have been used to predict long-term changes in all bird species across Europe; Durham’s ornithological expert Brian Huntley has compiled 'A Climatic Atlas of European Breeding Birds’ to map potential changes in distribution of all of the continent’s regularly occurring nesting birds.

His work shows the need for urgent action on climatic change to avoid calamitous impacts on birds.

The new work has important implications for predicting future trends. Researchers can now look at what has happened in the past to help predict the future species and numbers of birds in Britain.