Migrating Ducks
Hundreds of migratory ducks (Dendrocygna autumnalis) fly as the sun sets in Palo Verde National Park in Bagaces, Guanacaste, some 200 miles northwest of San Jose, Costa Rica, March 9, 2004. This 20,000-hectare park bordered by rivers and a ridge of limestone hills is home to some 250,000 migratory birds, such as teal, geese and ducks that arrive from North America to winter in the park, making up one of Central America's largest concentrations of waterfowl and wading birds, both native and migratory. REUTERS/Juan Carlos Ulate