The American kestrel is a small, colorful raptor often seen perched on a wire or hovering over a field. Its populations were expanding when much of the northeastern United States was covered with natural grasslands or agricultural fields. During the 20th century, changes in farming practices, nest cavity competition from introduced species, and loss of suitable habitat caused its numbers to decline. Help from humans, including habitat conservation and an increase in nesting sites, is needed to prevent further serious population losses.