Benefits of protected area networks for breeding bird populations and communities

Protected areas are a cornerstone of international conservation. The EU Natura 2000 network is the largest coordinated network of protected areas in the world, but its impact on biodiversity at the landscape scale is largely unknown. Here, we use data from Breeding Bird Survey (BBS) survey squares across Britain to test whether species abundance and population trends and levels of bird community specialisation are correlated with protected area coverage of BBS survey squares or 5-km buffers around BBS squares. We compared area coverage by Natura 2000 protection and by the less strict protection of Sites of Special Scientific Interest protection alone. The abundance of birds of higher conservation concern and an index of community specialisation were positively correlated with coverage by protected area within survey squares and in a 5-km buffer around squares. Population trends of species of higher conservation concern were positively correlated with the coverage of squares by Sites of Special Scientific Interest and the coverage of Natura 2000 within a 5-km buffer around squares. The results suggest that Natura 2000 protection, in particular has positive conservation benefits for birds of higher conservation concern and community specialisation. This highlights the importance of protected areas, especially those with strictest protection, for maintaining biodiversity. Post-Brexit, the UK should adopt legislation that results in the maintenance and strengthening of the current protected area network, as enforcing protection at a level of that provided by the Nature Directives is essential. As currently around half of Natura 2000 sites are not in favourable condition, even greater conservation benefits might be accrued if protected area management were improved.