Measures of predator diet alone may underestimate the collective impact on prey: Common buzzard Buteo buteo consumption of economically important red grouse Lagopus lagopus scotica

摘要: Human-wildlife conflicts often centre on economic loss caused by wildlife. Yet despite being a major issue for land-managers, estimating total prey losses to predation can be difficult. Estimating impacts of protected wildlife economically important also help management decisions evidence-led. The recovery in population and range common buzzards Buteo buteo Britain has brought them into conflict with some gamebird interests. However, the magnitude any impact is poorly understood. We used bioenergetics models that combine measures buzzard abundance from field surveys diets assessed using cameras at nests, remains pellet analysis, estimate their red grouse Lagopus lagopus scotica large (115 km2) moor managed shooting Scotland. Whilst consumption individual was lower than previous estimates other raptor species present our study site, could greater given an estimated 55–73 were site year-round. Averaging across diet assessment methods, during each three breeding seasons (April-July 2011–2013), foraging consumed 73–141 adult 77–185 chicks (depending year). This represented 5–11% April (22–67% mortality) 2–5% hatched (3–9% chick mortality). During two non-breeding (August-March), analysis ate 242–400 grouse, equivalent 7–11% those start August 14–33% mortality season. Buzzard potential lead non-trivial managers, but only if predated they ate, additive causes.