Local improvement of skylark and corn bunting population trends on intensive arable landscape: a case study of the conservation tool Natura 2000

For the past 20 years, different policy and regulatory tools such as the agri-environment schemes (AES) and the Natura 2000 network have been used in Europe to halt the ongoing decline of farmland birds resulting from agricultural intensification. Despite their wide implementation, bird populations are still declining at national and European scales, thus questioning the effectiveness of these schemes. Here, we examined the impact of the designation in 2004 of a Special Protection Area (SPA) for the little bustard on the local trends of two non-targeted, common but declining farmland birds, the skylark and the corn bunting, in an intensive arable landscape of western France. From 1996 to 2012, trends in skylark presence or abundance decreased whereas trends in corn bunting abundance first decreased and then showed a recovery; the trends differed between outside and inside the SPA. Outside the SPA and consistently with trends at the national and European scales, skylark abundance sharply decreased whereas corn bunting abundance first decreased and then stabilized or even slightly increased. Within the SPA, the skylark declined less, and the corn bunting abundance increased at a faster rate than outside. Our results suggest that the implementation of a SPA in this arable landscape had a positive impact on these two farmland passerines, at least for corn buntings, for which the implementation of AES clearly improved habitat. Our results also suggest that the extensive implementation of SPAs may have had a positive impact on bird population trends in farmlands at a regional level, where c. 150000ha (15-20% of total arable landscape) have been designated since 2004. However, the SPA network (within Natura 2000) currently covers a mere 3.7% of French arable landscape, and it is therefore no surprise that specialist birds in farmland are still declining nationally.