As habitats are lost and become more fragmented, there is less suitable habitat available, and threats to adult birds and their young increase. Mammalian and avian predators and brown-headed cowbirds tend to be more abundant in fragmented landscapes. In addition, tower strikes during migration and predation by free-ranging house cats have been estimated to kill tens of millions of birds each year. Migration is physically demanding - birds require quality habitats along migration routes to rest, replenish fat reserves and escape predators. The loss of habitat along migration routes reduces chances for survival.
Many species usually have only one chance at successfully fledging young.
If the first nest is destroyed or preyed upon, a second nesting attempt usually has a much lower probability of success. Research on Neotropical wintering grounds has revealed that, as with breeding habitat, many species require specific habitat types during winter months. The continuing loss of habitat in the Neotropics has a grave impact on overwinter survival of birds and decreases the probability of successful migration and breeding the following spring. Create or enhance backyard habitat for migrant birds Find out about how to prevent birds from accidentally striking your windows Read about the impacts of free-ranging house cats on bird and small mammal populations Become active in your community to conserve open space for wildlife and people You can find out more about these activities in the Web Resources and Books and Publications listed below. Managing Stopover Habitat for Migratory Land Birds J. P. Tash, E. Stiles and L. Widgeskog.