Human disturbance alters the predation rate of moose in the Athabasca oil sands

Abstract

AbstractHuman disturbance can alter predation rates to prey in various ways. Predators can use human disturbance to facilitate hunting, thereby increasing exposure to prey. Conversely, when predators avoid human disturbance and prey do not, prey refugia are generated. Because the direction and magnitude of such effects are not always predictable, it is important to examine if and how predation rates vary with human disturbance. Alberta's Athabasca oil sands region (AOSR) is a region of boreal forest characterized by extensive human disturbance and is home to moose (Alces alces) and wolf (Canis lupus) populations. We examined whether the wolf predation rate of moose varies with human disturbance in the AOSR. We compared the distribution of wolf kills of moose to a spatial index of moose density in uplands and wetlands, near and far from rivers, mines and facilities, and at high and low densities of linear features near human habitation. Moose were killed closer to mines and rivers and at lower densities of linear features than expected by random. When compared to the relative availability of habitats, more kills of moose occurred in upland forest than in wetlands. However, when compared to the relative density of moose, kills only increased with decreasing distance to mines and rivers. We conclude that predation rates of moose have increased near human disturbance in AOSR because the mining footprint has removed habitat causing changes to the intensity of wolf use of areas near the boundary of mines. We discuss possibility of sink habitat near mining features and whether that is expected to reduce moose population density across AOSR.