Some were hunted, but habitat loss or alteration was responsible for most losses. Around the turn of the twentieth century, conservationists began efforts to preserve habitats so that birds, especially plumed wading birds, could survive. Legislation was initiated to assist in the conservation of birds and to manage hunted species. Today, many public and private conservation agencies are involved in managing bird populations and their habitats. Birds are important components of ecosystems.
Birds disseminate seeds and prey upon innumerable insect and vertebrate pests.
They are involved in energy transfer as they eat and are eaten. Nutrients are also distributed through the movement of birds. Vultures, crows, ravens, and other scavenging birds are important in natural decomposition cycles. Because birds are not isolated components of our natural systems but integral parts of them, it is vital to understand both their roles and their needs. Information must be available on the species present in the area, their habitat requirements, and how birds will respond to habitat alterations.