Falcon Nest Occupancy and Hatch Success Near Two Diamond Mines in the Southern Arctic, Northwest Territories

Abstract

Sensitivity to anthropogenic disturbance in conjunction with slow population recovery has raised conservation concerns over impacts to raptor species from industrial development in pristine areas of their North American breeding range. We evaluated whether the presence of two diamond mines resulted in negative effects to nest use and hatch success of breeding falcons in the southern Arctic barren-grounds of the Northwest Territories. A total of 20 nest sites of Peregrine Falcon (Falco peregrinus) and Gyrfalcon (Falco rusticolus) breeding within 26 km of the Diavik and Ekati diamond mines were monitored annually during 1998 to 2010. The objective of the study was to test the effects of distance from mines, relative nest age, rainfall, small mammal abundance, and mine activity levels on nest occupancy and hatch rates. Model selection results indicated that nests that were older were more likely and consistently used than nests that were established more recently. A decrease in nest use associated with the mines was not detected. Hatch success was best explained by a positive association with distance from development and a negative trend over the study period, however, these effects were weak. Hatch success of nests within and beyond an estimated 5.9 km distance threshold was similar, and for nest sites within this distance was unrelated to annual changes in accumulated mine footprint area through time. Hatch success for nest sites near Diavik was unrelated to changes in this mine's activity through time. Although natural and anthropogenic effects were generally weak, the lines of evidence suggested that the observed patterns were more likely the result of natural factors operating at a regional scale than more localized effects from the activity of two diamond mines.

Keywords

• Arctic
• development
• falcons
• mine
• nest success
• occupancy
• sensory disturbance