Palo Verde National Park was declared a wildlife refuge during the 1970s because over 60 species of birds used the laguna, or wetland, as a migratory stop. There were once 35,000 black bellied whistling ducks, 25,000 blue winged teal, and several hundred migrating ducks during the dry season.
Palo Verde National Park was established as a wildlife refuge in the 1970s because it provided a critical stopover point for over 60 bird species that used the lagoon. The park had previously supported large populations of black-bellied whistling ducks, blue-winged teal, and migrating ducks during the dry season.