Temporal Variation in Space and Resource Use of Macaws in the Southeastern Peruvian Amazon

Space use and resource use of three species of macaws (Ara ararauna, A. chloropterus, and A. macao) were studied for a period of three years in the southeastern Peruvian Amazon. Basic information on wild macaw populations is lacking due to the logistical and behavioral challenges of working with these species in dense rainforest. Population declines world-wide have been attributed significantly to a reduction in food and nesting resources due to habitat loss. This research aims to obtain baseline data on macaws in a region with relatively intact rainforest. Specific objectives were to (1) quantify space use, describe the spatial and temporal variation in movement patterns, explore habitat selection and spatial pattern of resources during the non-breeding season, and (2) identify key nesting and foraging species and determine whether there is seasonal variation in diet, and explore how resources may be related to movements and competition.

Individuals from each species were radio-tagged and monitored from 2004 to 2008 by ground, platform, and aerial tracking. Seasonal ranges were estimated using MCP and KDE methods. Diversity and niche measurements and selection were calculated for dietary items, nesting substrate, and habitat. The relationship between palm habitat distribution and A. ararauna movements was explored using landscape analysis techniques.

All species had similar home range sizes during the breeding season, ranging from a mean of 1,540 ha to 2,541 ha. Non-breeding ranges were significantly larger for A. ararauna (117,849 ha). Greater than 200 species of plants were consumed, yet seasonal preferences vary. The increase in dietary breadth and decrease in overlap during dry season is unlikely related to food scarcity or competition. Key nesting and dietary species include Mauritia flexuosa, Dipterix micrantha, and Bertholletia excelsa. Palm habitat is a key resource for Ara ararauna and associated with long-distance movements.

This research addresses a critical gap in our knowledge regarding macaw movements and resource use in Amazonian rainforest. Despite their mobility, their low fecundity and specialized nesting requirements can impact reproductive success and population growth if habitat loss continues on its current trajectory.