Influence of in situ oilsands development on occurrence of an avian peatland generalist and specialist

Demand for petroleum products is causing habitat loss, alteration, and fragmentation of boreal forests in western Canada. Associated exploratory and extraction activities from in situ oil sands leave a network of (1) permanent polygonal features (e.g., processing facilities, extraction sites, gravel pits); (2) permanent linear features (e.g., roads, pipelines); (3) temporary polygonal features (e.g., exploratory well sites); and (4) temporary linear features, (e.g., winter roads, seismic lines). We examined the impact of these different types of disturbances on the occurrence of a generalist, the Dark-eyed Junco (Junco hyemalis) and a peatland specialist, the Palm Warbler (Setophaga palmarum) for an in situ development-lease area in northeast Alberta, Canada. Our goal was, first, to determine if energy development features have positive, negative, or neutral effects on species occurrence, beyond the amount of habitat disturbed, and second, to identify the relative impact of different types of energy features. Permanent polygonal features negatively influenced both species, decreasing the odds of occurrence for Dark-eyed Juncos by 0.63 times and 0.44 times for Palm Warblers for every 10% increase in percent area. However, permanent linear features increased odds of occurrence for Dark-eyed Juncos by 1.73 times and Palm Warblers by 3.93 times. We speculate that permanent linear features increase vegetation heterogeneity or influence insect-prey availability through edge effects. Although permanent polygonal and linear features had opposite effects (negative and positive, respectively), they had a similar relative effect on occurrence for both species. There were no effects of temporary polygonal or linear features on occurrence for either species examined here. Whereas our understanding of birds in boreal peatland forests is limited, these results are consistent with studies that suggest permanent linear features have more substantive local scale impacts than temporary disturbances.