Resource availability in a heterogeneous environment and density-dependent processes may influence the spatial distribution of individuals among habitats. The distribution of nests of secondary cavity nesters is rarely clumped because the birds are constrained by the distribution of existing cavities as nest resources. In this study, to evaluate the interplay of environmental and behavioral processes in the spacing of parrot nests, we compared the spatial distribution of active Lilac-crowned Parrot (Amazona finschi) nests with that of all cavities used as nests over 14 years. Parrots reused 42% of cavities, and the frequency of reuse was significantly associated with a previously successful nesting attempt. Positive fitness benefits of cavity reuse may indicate high-quality nest sites that are used more intensively by resident breeding pairs. Spatial-point-pattern analysis indicated that trees used as nests were significantly clustered within 60 m in the three nesting areas, with average distance of 100–200 m between nest trees. In a given breeding season, active parrot nests were separated by a mean 950 ± 890 m. Parrot nests were also located significantly closer to a tree used as a nest in the previous breeding season than the distance between nearest nesting conspecifics. This pattern suggests that conspecifics influence the spatial distribution of reproductive pairs breeding simultaneously, with nesting pairs occupying areas where suitable cavities are more numerous. The behavioral spacing requirements of nesting parrots may limit breeding densities and restrict management strategies to increase numbers of nesting pairs within protected areas.
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The Condor
Vol. 111 • No. 2
May 2009
Vol. 111 • No. 2
May 2009
Amazona finschi
cavity reuse
Chamela—Cuixmala
nest spacing
Psittacidae
semi-deciduous forest
tropical dry forest