Practitioners' perceptions on ecological restoration: activities, challenges and solutions on two small oceanic islands.

Ecosystem degradation worldwide causes biodiversity loss and negatively impacts their functioning, eroding the services they provide to the detriment of society and human well-being. The magnitude of this crisis makes ecological restoration a global priority, but progress has been hampered by a variety of factors including a low uptake of evidence-based management by practitioners, limited monitoring of restoration success, and social and political drivers occurring in competitive, multi-stakeholder management contexts. Exploring practitioners' opinions, perceptions and motivations can thus provide useful insights and identify barriers to upscale ecological restoration and increase its effectiveness. This study aimed to assess the rationale behind the implementation of current restoration activities, and characterise the barriers to adopt improved approaches that have been shown to be more cost-effective. Using a questionnaire-based survey on Mauritius and Rodrigues oceanic islands, both well-known in the fields of terrestrial ecological restoration and conservation, we explored (1) the modalities of restoration activities implemented for native terrestrial habitats conservation, (2) challenges impacting their implementation, and (3) potential solutions from conservation practitioners' perspectives. We interviewed 54 conservation practitioners, conducted a hierarchical clustering analysis to categorise the restoration activities they implement, and identified the most frequently perceived challenges hindering them, along with the perceived solutions foreseen to improve restoration success. Four clusters of activities were identified. Restoration activities are dominated by the control of invasive species,