Human disturbance of grouse - why and when?

Disturbance caused by human outdoor recreation and tourism activities is increasingly viewed as a threat to wildlife. Particularly in areas where threatened populations of wildlife overlap with highly frequented tourist locations, managers are challenged with reducing impacts of human disturbance on wildlife. For grouse, Tetraonidae, most studies on the effects of human disturbance address individual responses, whereas for conservation, the most relevant question is whether human presence negatively impacts the abundance and viability of populations. I here summarise published studies on the responses of grouse to the presence of humans, review the conceptual foundations of predation-risk theory and the risk-disturbance hypothesis, and propose a framework for research to aid conservation of grouse. Because grouse are found in many environments they are excellent model species for testing the predictions of the risk-disturbance hypothesis.