Distribution of exotic monk parakeets across an urban landscape

Monk parakeets (Myiopsitta monachus) are the most abundant and widely distributed of the naturalized parrots in the United States. Their presence is simultaneously encouraged by some humans (through use of bird feeders) and discouraged by others (through removal of their nests) and, as a result, they show an interesting spatial distribution across urban areas. We used an online public survey and field surveys to examine the influence of human activities and land use on the distribution of this exotic species around Chicago, IL (USA). These efforts resulted in detection of 249 nesting structures and approximately 778 birds across the region. A CART analysis successfully separated nesting sites from random sites and correctly classified 90?% of the nesting sites. The most important factor in the model was land use, with nests typically found in areas with less than 84?% residential zoning. We found nests on a wide variety of substrates including trees, cell phone towers, and stadium lights. Spatial point pattern analysis indicated that nests in trees and nests in built substrates were significantly dissociated with each other at all scales. Nests on built substrates were closer to railroads and highways or in areas with lower human population density, suggesting either a difference in substrate availability or human tolerance between these settings. While humans may have a positive effect on distribution of monk parakeets at large spatial scales, at the scale of this study we see a potentially negative effect of too many humans on the distribution of monk parakeet nests.