Functional and numerical responses of ovenbirds (Seiurus aurocapilla) to changing seismic exploration practices in Alberta’s boreal forest

Abstract

:Rapid development of energy reserves in the boreal forest of western Canada has raised concerns about the potential impacts of forest fragmentation caused by seismic lines. Seismic lines are narrow linear corridors cut by the energy sector to access remote areas. Traditionally, seismic lines were cut using a bulldozer and averaged about 8 m in width. In response to concerns about conventional seismic line impacts, some energy companies have turned to new “best practices” that use lower-impact techniques to reduce their footprint (2- to 3-m-wide lines). Crucial to assessing the efficacy of this change in seismic policy for maintenance of biodiversity is determining how conventional and low-impact seismic lines are perceived by wildlife. We assessed the functional and numerical response of male ovenbirds (Seiurus aurocapilla) to conventional and low-impact seismic lines in mature aspen forest in northeastern Alberta. Based on radio-telemetry, ovenbirds perceived conventional seismic lines as creating a gap in the forest and used it as a territory boundary. In contrast, ovenbirds incorporated low-impact seismic lines within their territories. Spot-mapping data suggested no differences in ovenbird density in stands with a single conventional seismic line, multiple low-impact lines, or reference plots with no seismic lines. Despite the lack of numerical response to any seismic practice, we believe it is prudent to recommend that energy companies consider using new low-impact approaches in their seismic operations to minimize the ecological risks of energy sector activity for forest birds.