Agonistic interactions of nesting and nonbreeding macaws
Condor
2004
Journal Article
106
2
354-362
Parque Nacional del Manu Ara ararauna cavity nesting intraspecific competition Psittacidae breeding biology clutch size territorial behavior site availability tree hollows house wrens birds competition density animal behavior ecology single-species study Blue-and-yellow Macaws small spatial scales Madre de Dios Bibliography
Agonistic interactions of nesting and nonbreeding Blue-and-yellow Macaws (Ara ararauna) were observed in the Manu Biosphere Reserve, Peru, during the nestling phase of the nest cycle in 1988 and 1989. Three nesting pairs of macaws were identified by facial line and tail patterns, and agonistic behavior was categorized as high-intensity or low-intensity interactions. Nesting pairs associated strongly with cavities and perch trees within the nest area, and frequently chased nonbreeding conspecifics from an area of up to 100 m from the nest. In one case, loss of control of the nest cavity and perch trees by a lone nesting macaw to a nonbreeding pair led to infanticide and abandonment of the nest. Agonistic interactions were predominantly intraspecific, and 79% of agonistic interactions by nesting macaws were directed at nonbreeding conspecifics. The frequency of agonistic interactions increased significantly with day of the nesting cycle, being greatest toward the end of the nestling period. Nonbreeding macaws spent significantly more time in trees at the edge of the nest area than in trees within the nest area, and significantly less time within the nest area when nesting pairs were present than when absent. In both years, only 36% of the available cavities within the nest area were utilized by Blue-and-yellow Macaws, though some cavities were utilized by smaller macaw species. Intraspecific interference competition of nesting macaws may exclude potential breeders from investigating cavities, effectively limiting availability where nest sites are clumped in distribution.