Long-term species records provide a good baseline in which to assess temporal variations at a range of spatial scales. This paper presents the results to date of a long-term avian monitoring program within the Credit River watershed, in Southern Ontario, Canada. Breeding bird populations have been monitored at 25 woodlots for the past nine years at sites representing a gradient of human impact across the watershed. The Credit River drains through three physiographic and corresponding land-management regions including agricultural land, urban centres and a biosphere reserve. Avian population patterns have been assessed at three spatial levels of land cover from the watershed to site-level and compared to temporal variability between breeding seasons. It was determined that diversity of avian guilds is a function of larger, regional patterns of physiography and land use. Similarly, at the landscape level increased pressures from land use and loss of habitat cause a shift from forest-interior to edge or urban species. However, at the landscape-level and site-level habitat diversity will influence temporal variations in population patterns. The presentation will conclude with a discussion of the role of core interior forests in the greater watershed with a focus on management of protected areas and impact of human stressors from increased interaction.