Conservation or co-evolution? Intermediate levels of aboriginal burning and hunting have positive effects on kangaroo populations in Western Australia

Studies of conservation in small scale societies typically portray indigenous peoples as either sustainably managing resources, or forsaking long-term sustainability for short-term gains. To explain this variability, we propose an alternative framework derived from a co-evolutionary perspective. In environments with long histories of consistent interaction, we suggest that local species will frequently be well adapted to human disturbance; but where novel interactions are introduced, human disturbance may have negative environmental consequences. To test this co-evolutionary hypothesis, we examine the effect of Aboriginal burning and hunting on hill kangaroo (Macropus robustus) abundance. We find that hill kangaroo populations peak at intermediate levels of human disturbance, showing that in ecosystems characterized by long-term human- environmental interactions, humans can act as trophic mediators, resulting in patterns consistent with epiphenomenal conservation. Framing the question within this co-evolutionary perspective provides an explanation for the underlying mechanisms that drive environmental outcomes of subsistence practices.