Adaptations to seasonal changes by migrant land birds in the Panama Canal ZoneSmithsonian Institution Press437–453
Morton, Eugene S. 1980. "Adaptations to seasonal changes by migrant land birds in the Panama Canal Zone." In Migrant Birds in the Neotropics: ecology, behavior and conservation. Keast, Allen and Morton, Eugene S., editors. 437–453. Washington, D.C.: Smithsonian Institution Press.