What are some human caused hazards for migrants?
Flying at night or in fog, many birds collide with tall structures. Lighthouses and skyscrapers are notorious killers of migrants. Reflective windows can be deadly. Birds see reflections of sky or trees and fly into them. Electronic towers for radio, television, cellular phones, etc. and their supporting cables kill thousands of migrating birds during migration. Habitat loss and degradation is a much greater problem. Habitat needed for food and shelter in winter is disappearing in Latin America. Clearing of forestland and plowing of grassland for crops destroys the diverse habitat that is necessary for many species of birds to survive. In the United States and Canada there is often not enough habitat for some species to raise their young. Where there is appropriate habitat, it may be too close to human disturbances or be too small an area. The populations of many North American bird species have decreased severely over the last 100 years. A serious man-caused hazard to migratory birds
