Predictive Models for Estimating the Cumulative Effects of Human Development on Migratory Landbirds in the Oil Sands Areas of Alberta

Executive Summary
Project results describe the habitats used by 81 species of forest songbirds and response by birds to human footprint (physical disturbance of vegetation cover by human activity). We used a modelling approach using data from surveys of boreal birds collected by Environment Canada, the Alberta Biodiversity Monitoring Institute, the North American Breeding Bird Survey, and additional data from studies also compiled by the Boreal Avian Modelling Project. The models described the habitat associations and responses to human footprint at two scales: at the station of the data collection (0.07 km2) and at the quarter-section (0.64 km2) around the stations.

Using an estimate of what this landscape would have looked like with no human activity, we predicted how the abundance and distribution of birds would differ from their current abundance and distribution. We also grouped different types of human disturbances according to ‘sectors’: agriculture, urban/industrial, mines/wells, energy related linear features (transmission lines, pipelines, seismic lines), forestry, and transportation related linear features (roads, rails).

The results across all 81 species showed that the overall impact of the different sectors on bird populations is proportional to the area of disturbed landscape associated with the various sectors. Agriculture and forestry had largest extent in the oil sands region, consequently these sectors contributed the most to the predicted population differences.

After standardizing the population differences by the area of disturbances, the unit area effects of vegetated and non-vegetated linear features were highest, and the impact was often disproportionate relative to the relatively small area of these disturbance types. Such disproportionate effects occur when a particular disturbance is affecting highly suitable habitats of a species, thus a 1% land cover change could result in >1% population difference.

The results can be used to improve management practices for migratory songbirds including several listed species, such as Canada Warbler and Olive-sided Flycatcher (both Threatened, Species at Risk Act), and Black-throated Green Warbler (Special Concern, Alberta Wildlife Act).