Abstracts

Presented by Stuart Slattery - Email: s_slattery@ducks.ca

The Western Boreal Forest (WBF) has changed rapidly due to industrial development. Implications of these changes for waterfowl are unknown though landscape changes are hypothesized to alter food availability and/or predation rates with subsequent negative impacts on demography. Linear features (roads, seismic lines, and pipelines) have the second largest anthropogenic footprint in crown-owned portions the WBF. Our objective was to assess relationships between these features and waterfowl settling and productivity, and thereby test predictions of food vs. predation mechanistic hypotheses. Waterfowl surveys were conducted using helicopters to count pairs and broods on grids (2.5km x 2.5km, n = ~100 per year, 2013 - 2016) distributed across gradients of linear feature densities in north-central Alberta. We used a double observer and repeated visit methodology followed by multinomial N-mixture models to examine relationships with linear features while correcting for detection probability and habitat biases. In addition, we tested for interactions between anthropogenic and natural linear features (riparian edge density). Analyses were conducted at both the wetland and grid levels. Most relationships between waterfowl metrics and anthropogenic linear features were neutral or positive, and, where negative, patterns were generally not consistent across nesting guilds, spatial scales or linear feature type. However, we did observe several interactions between riparian edge density and road and pipeline density. In these cases, roads tended to have negative relationships at lower riparian edge density, while the pattern was opposite for pipelines. Our results provided limited support for either mechanistic hypothesis and are generally consistent with other studies. Boreal waterfowl appear to be resilient to landscape changes at current levels.