In recent decades, significant efforts have been made, and a considerable amount of money has been invested in designing and constructing wildlife measures on road networks. These measures help to reduce habitat fragmentation and to prevent road kill of wildlife due to transportation infrastructure. Such measures may be limited in their effectiveness by the lack of appropriate maintenance. Moreover, road verges and other green areas linked to roads and railways have been highlighted as wildlife habitats that could play a role in enhancing biodiversity conservation and ecological connectivity, particularly in densely populated areas. In this regard, maintenance practices emerge as a fundamental factor in reducing long-term road impacts. The aim of our study was: i) to provide an overview of current road maintenance practices regarding wildlife in Europe, ii) to identify opportunities and best practices that enable adaptive management of wildlife-related issues, and iii) to provide guidelines for road maintenance to reduce hazards for road users and wildlife, enhance biodiversity, and strengthen the European Green Infrastructure. We interviewed 24 professionals involved in road maintenance from 11 European countries, carried out a literature review, and organised a workshop that brought together road and wildlife experts. The final output was a set of guidelines for the maintenance of roads and their surroundings from an ecological perspective. Most relevant ones have been included in the Roads and Wildlife Manual, published by the Conference of European Directors of Roads (CEDR) in 2018. Road managers are recommended to adopt a flexible strategy and a lifecycle approach to guarantee the long-term effectiveness of wildlife mitigation measures, to identify better cost-efficient strategies and to use wildlife conservation opportunities. Appropriate road–wildlife maintenance strategies should include: i) standards for wildlife mitigation measures to be met according to both the instructions provided by designers and constructors, and the road safety and operational requirements; ii) scheduling inspection and maintenance tasks adapted to the local conditions of wildlife and habitats; iii) establishing procedures for identifying conflicts or deviations and how to solve them; iv) defining proper training programmes for maintenance crews; v) defining methods for monitoring and reporting in compliance with standards, and disseminating this information to road planners and other stakeholders involved. Instructions for the inspection and maintenance of wildlife fencing and screens, wildlife crossing structures and wildlife awareness devices are provided to improve traffic safety, and to funnel animals to safe crossing points. Additionally, a number of Best Management Practices (BMPs) on maintenance of road verges, landscaped areas, retention ponds, and other aquatic habitats associated with drainage systems are described. Attention must be paid to avoid the risk of creating ecological traps, i.e., habitats that attract animals to areas with a high mortality risk. Early detection and removal of alien invasive species, that could damage local habitats or species, is also envisaged as a critical factor to be applied to road maintenance procedures. An overall strategy that considers and integrates information on the maintenance of wildlife mitigation measures and roadside habitat management will provide appropriate risk assessment and identify the BMPs that have to be applied.
Murcia
