Monitoring, modelling and managing beaver ( <i>Castor fiber</i> ) populations in the River Otter catchment, Great Britain

Eurasian beaver (Castor fiber) were nearly hunted to extinction but have recovered occupy much of their former range. Beaver extirpated from Great Britain c. 400 years ago recently been reintroduced. The River Otter catchment, Devon was the site first licensed wild release beavers in England. With further releases being considered, there is a need better understand population dynamics this native, keystone species inform conservation and management. Field signs surveyed 2015 2021. A semi-automated territory detection method adopted estimate counts. spatially explicit model developed ecological capacity catchment. Future expansion modelled using logistic growth curves; initial rate estimated observed counts range used define limiting value curve. removal simulated, across management intensities start times, determine potential impacts translocation or lethal control upon dynamics. Territory numbers increased four 18, inclusive additionally released individuals, during study period. In absence management, catchment between 120 183; may be reached 2028 2057. Simulated removal, where territories removed at fixed sum total increase for that year, demonstrated large uncertainties predicted responses. Simulations with removals >3/year all collapse. This finding emphasizes caution when considering strategies; animals out culling should considered only populations are established alternatives considered. These results provide critical information expected magnitude change methods reproducible generalizable approach understanding change, which can policy on reintroduction timing intensity future