Raptors face a variety of human-induced threats such as habitat loss and degradation, illegal shooting and poisoning, collisions with aerial structures and electrocution by power lines. Migratory raptors are particularly at risk due to the often long and arduous annual journeys from their breeding grounds to wintering areas and back.  Moreover, some species either migrate in large groups or form major concentrations along their flyways, for example, at narrow land bridges or sea crossings, which enhance the potential impact of some threats.