Conservation efforts for waterbirds, such as the Dalmatian pelicans (Pelecanus crispus) pictured on the cover, have centred on creating protected areas to maintain suitable habitats. But it has been unclear to what extent protected areas affect species’ population levels. In this week’s issue, Hannah Wauchope and her colleagues present an analysis that suggests protected areas have a mixed impact on waterbird populations. The researchers examined 1,506 protected areas to assess how they affected 27,055 waterbird populations across the globe. By assessing population levels before and after the implementation of protection, and comparing this change between protected and unprotected areas, the researchers identified the mixed impact, but also saw a strong indication that areas that were managed for waterbirds or their habitats were more likely to benefit populations. As a result, the team suggests that conservation strategies will require not only an increase in the number of protected areas, but active management of those areas to have the best chance of success.