The goal of this study is to further our understanding of the population status, reproductive success, habitat needs, and potential limiting factors for breeding populations of montane forest birds in the Santa Catalina Mountains of southeastern Arizona. Mixed-conifer forest and Madrean pine-oak woodlands support a unique and diverse avian community. This avian community is vulnerable to disturbance because the area encompassed by montane forests represents only a small fraction of the total landmass of the region. Moreover, the highest densities of breeding birds in the Santa Catalina Mountains are concentrated in a relatively small number of drainages that contain montane riparian vegetation. In recent years, the potential for disturbance to these important breeding areas has increased dramatically. We lack not only a clear understanding of the potential impact of these threats on forest birds in southeastern Arizona but also basic information on the population status, reproductive success, and habitat needs for the vast majority of these species. We propose to assess population status by conducting breeding bird surveys on ten study plots. We will determine reproductive success and habitat requirements for breeding birds by locating and monitoring nests and measure vegetation characteristics at nest sites (and at random points for comparison) within each plot. In addition, we will evaluate the effect of human disturbance and recent wildfires on breeding bird populations.