Seven decades of mountain hare counts show severe declines where high-yield recreational game bird hunting is practised

1. Recreational hunting is widespread and can benefit nature conservation when well-practised, monitored, and regulated. Management for recreational red grouse Lagopus lagopus scotica shooting on upland heathland in the UK causes conservation conflict because the intensive habitat, predator, and disease management needed to maintain high-grouse densities for "driven" shooting has detrimental environmental impacts, notably for raptor populations. 2. Sustainable management of mountain hares Lepus timidus scoticus, a game species in the same landscapes, poses a challenge. Control of transmission to grouse of a viral disease, louping-ill, for which mountain hares are a host, has become an additional motivation to kill mountain hares since research during 1993-2001 suggested that culls might reduce infection rates in grouse. 3. We analysed population trends of mountain hares from spring counts on moorland managed for grouse shooting and on contiguous alpine land. On moorland sites, a long-term decline (4.6% per annum) from 1954 to 1999 increased to 30.7% per annum from then until 2017, with a density index falling to