Abstract: Bird is one of the main threats causing flashover trip and affecting the safety of transmission lines. The diversity of birds and the complexity of their activities make it challenging to predict their consequences on power systems. To prevent potential threats from birds, it is important to understand the linkages between bird traits and habitats and their risks to transmission lines. In this study, we investigated birds on and around the transmission lines in Jiangmen City, Guangdong Province. We identified the bird species with high risks to the safety of transmission lines, and the associated functional traits. We found that bird species inhabiting on transmission lines had significant different traits compared with those stayed away from transmission lines. The differences in traits primarily affected the frequencies rather than the presence of birds on transmission lines, based on the results from a zeroinflated Poisson model. The high-risk bird species (occurred frequently on transmission lines) were native species with long body size, weak migration ability, small distribution range, and more habitat specificity, such as Acridotheres cristatellus and Sturnus nigricollis, the two species with the highest frequencies of occurrence on transmission lines. The principal component analysis showed that the habitat of high-risk was with high proportion of shrub, intense anthropogenic disturbance and habitat fragmentation. Our results provide fundamental knowledge useful for developing strategies to control high-risk birds on transmission lines, and to balance the control and conservation of birds in cities.

Key words: transmission line, birds, trait, zero-inflated Poisson model, habitat.