Hierarchical scales in landscape responses by forest birds

Selection of habitat by birds is manifest at different geographical scales. Most bird communities in forested ecosystems of the northern hemisphere are comprised of migratory species that represent more than 70% of the species and individuals within a forest patch. Historically from the 1950s to 1970s most studies were focused on the response of forest birds at the patch or forest stand scale. Since the 1980s, field studies have determined both microhabitat needs (e.g., individual trees or species) or the importance of entire landscapes in which populations occur. Advances in computation power, remote sensing, geographic information systems, and multivariate analytical techniques have greatly enhanced our understanding of bird habitat associations at these multiple geographic scales. Based on results for over 50 species, we illustrate the responses of forest birds in the Great Lakes region at three spatial scales: microhabitat, forest patch, and landscape. Management opportunities are easiest to implement at the forest patch scale, but cognizance of natural disturbance regimes, basic life history needs, and landscape context can enhance opportunities for conserving native forest bird assemblages.