{Global distribution and conservation of avian diet specialization}

Ecologically specialist species are more prone to extinction than generalist species, yet the global distribution and conservation of ecological specialism is poorly understood. Here, we show that the global distribution of avian dietary specialization is roughly congruent with overall bird species richness for resident and breeding species, as well as for non-breeding species. However, some areas harbour a higher number of diet specialist birds than expected given overall species richness (e.g. the Amazon, Gabon and Cameroon in Central Africa, extensive parts of Indonesia and some parts of northern Eurasia, Baltic cost and Mediterranean areas for resident and breeding birds, and tropical zone and south part of subtropical zone in South America for non-breeding birds). These areas represent hotspots of avian specialization that need to carefully be considered in conservation strategies. We found that overall, 49.6% of resident and breeding species and 45.5% of non-breeding diet specialist species are adequately represented by the global protected area system, but that this percentage is lower for the most threatened species. Policies that modify conservation planning approaches to include measures of specialization alongside other more traditional metrics of biodiversity could improve the protection of biodiversity in the face of rapidly accelerating anthropogenic threats.