Differential use of space by eight species of birds in a free-flight zoological park aviary

Abstract

Eight species of birds (jabiru stork, Jabiru mycteria; maguari stork, Euxenura galeata; king vulture, Sarcoramphus papa; turkey vulture, Cathartes aura; black vulture, Coragyps atrata; Orinoco goose, Neochen jubata; fulvous-whistling duck, Dendrocygna bicolor; black-bellied whistling duck, D. autumnalis) were studied in a large zoo aviary to determine their use of topographical regions (areas), substrates and heights during a 3-month period. Positions of individuals in the aviary were recorded and species were compared to others of the same taxonomic family to determine if they exhibited differential use of space. Resting and self-care were the most frequently recorded behavior patterns. Certain areas, substrates and heights were utilized by each species regardless of behavior. Each species restricted most of its activity to two or three contiguous areas within the aviary. Space use was correlated with the location of food, presence of shade or similarity to substrates utilized in the wild. Only the vultures made appreciable use of heights over 1.5 m above ground level. Conspecifics were found with each other more often than with heterospecifics of the same family. The waterfowl and maguari storks tended to flock. Maguari storks, king vultures, Orinoco geese and fulvous whistling ducks were restricted in their use of space while the other species ranged throughout the aviary. Environmental structure strongly influenced space utilization, and there were indications that intra- and interspecific interactions may have also affected use of space.