Identification of urban flight corridors for migratory birds in the coastal regions of Shenzhen city based on three-dimensional landscapes

Context The rapid urban expansion in southern coastal regions of China can endanger the quality and connectivity of bird habits and thus challenge our capacity for protecting bird species in urban areas. Identifying the ecological corridors that allow migratory birds to and from urban green landscapes is therefore essential for conserving biodiversity in urban areas. Objectives This study aimed to explore how urban expansion in vertical direction affects the flying paths of migratory birds and seek measurements to enhance bird migration to and from urban areas. Methods The ecological security pattern (ESP) for migratory birds in a coastal region near the Shenzhen city of China was determined based on three-dimensional landscape data and results were evaluated against historical eBird record abundance data. Results The positive agreement with historical bird abundance demonstrated that the consideration of three-dimensional landscape in parameterizing the resistance for ESPs can help identify the flight corridors for migratory birds in urban areas and the consequent sixteen key flight corridors with a total length of 454.78 km were identified in and around the Shenzhen city. Conclusions The three-dimensional landscape data are essential for identifying flight corridors for migratory birds to and from urban landscapes. The extracted flight corridors in and around the Shenzhen city connected natural reserves with urban parks, thereby enlarging bird habitats and its conservation inside the Shenzhen city.