Effectiveness of woodland birds as taxonomic surrogates in conservation planning for biodiversity on farms

Abstract

Woodland birds are a commonly used taxonomic surrogate for other species groups in agricultural landscapes as they are relatively diverse, easily-studied, and charismatic. Yet, other taxa can respond to native vegetation on farms differently to woodland birds, challenging the present focus on birds in agri-environmental schemes. We aimed to assess the effectiveness of woodland birds as taxonomic surrogates for biodiversity in conservation planning on farms, in comparison with reptiles and arboreal marsupials. We used a complementarity-based approach to select patches of remnant and restored vegetation that supported a priori representation targets of species occurrences. We found that the spatial locations of vegetation patches selected to meet representation targets for woodland birds were 24%–69% different from the locations of patches selected for other taxa. The vegetation patches selected to meet representation targets for woodland birds failed to incidentally meet representation targets for other taxa, although targets for a subset of threatened woodland birds were exceeded. Conservation planning for woodland birds, however, led to higher incidental representation of the other taxa, compared with conservation planning for reptiles and arboreal marsupials. This indicates that woodland birds are a more effective taxonomic surrogate for biodiversity on farms compared to reptiles and arboreal marsupials. If the conservation goal is to conserve a broad array of biodiversity on farms, then the focus on woodland birds in agri-environmental schemes is justified. However, if the conservation of particular species or taxonomic groups is a priority, then conservation plans explicitly targeting these species or groups are required.