Protected wildlife areas in Britain are proving to be \"welcome mats\" for new bird species colonizing the country in recent decades, experts say. Researchers at the University of York and the Royal Society for the Protection of Birds said bird species new to Britain initially breed almost exclusively in nature reserves and other areas specially protected for wildlife. \"Nature reserves provide ecological welcome mats for new arrivals,\" York doctoral student Jonathan Hiley said in a university release Wednesday. Writing in the journal Proceedings of the Royal Society B, the researchers report of the 20 wetland bird species that bred for the first time in the United Kingdom since 1960, 18 bred first in these protected areas. Protected areas were crucial as the population established, then the birds began to spread out into other locations, expanding their ranges across the country, the researchers said. Species shifting their ranges in response to climate change need high-quality places to move into, they said, and for birds at least it appears the current network of protected areas in the United Kingdom is providing such places. \"This gives some cause for optimism in the midst of concern that climate change and other factors will imperil many species,\" York researcher Chris Thomas said. \"Protected areas are helping to give birds and other species a fighting chance of moving into new regions where they can breed successfully.\"