Avian populations in human-dominated landscapes: An analysis of spatio-temporal dynamics at the urban-rural interface

To measure the ecological effects of urbanization this research focuses on bird-habitat relationships at the urban-rural interface by: investigating static and change relationships between local landscapes and local birds (Chapter 2); proposing and evaluating the use of bioacoustic recording equipment for avian point-sampling in an urbanized environment (Chapter 3); and, testing the relationships between forest birds and the landscape characteristics of forest and developed land covers (measured via development density) that are commonly intermixed in the study region (Chapter 4).;I assessed the relationships between compositions and changes of landscapes and avian abundances in Southeast Michigan using three bird guilds to group species of interest including woodland, grassland, and urban birds. The predominant landscape changes were agricultural abandonment, urbanization, and afforestation. I found that grassland and urban birds experienced the most consistent declines and that both average species richness and total abundance of birds also consistently declined. These results highlight that some bird guilds (e.g., grassland birds) suffered significant declines associated with habitat loss, while other guilds (e.g., woodland birds) did not respond to marked habitat increases. Then, I tested the effectiveness of omni-directional bioacoustic recording equipment versus traditional in situ point counts, along an urban-rural gradient. I found that recording-based interpretations were subject to the same ambient noises, and similar resulting levels of distraction associated with those noises, as were field-based observations; and, although not in perfect agreement with field-based observations, recordings can serve as an effective point-count mechanism in urbanizing environments. Finally, to explore how habitats within developed landscapes can be beneficial to birds, I tested community and species-level effects of patch- and matrix-characteristics on bird richness and occurrence. I found that focal-patch area is the primary contributor to a site's overall species richness, but that the addition of matrix tree-cover area influences the ability of the patches to support many forest-obligate species, especially Neotropical migrants. This relationship suggests that the amount of matrix tree cover surrounding woodlots, parks, and other preserved set-asides may play a critical role in supporting area-sensitive species in urbanizing environments.