Response of Bicknell's Thrush (Catharus bicknelli) to boreal silviculture and forest stand edges: a radio-tracking study

Society and regulatory regimes require that biodiversity conservation, and especially the protection of threatened species, be integrated into land-use planning and management. Bicknell's Thrush (Catharus bicknelli (Ridgway, 1882)) is an at-risk species breeding in montane balsam fir (Abies balsamea (L.) P. Mill.) dominated areas of northeastern North America. We monitored 34 individual Bicknell's Thrushes by radio telemetry in southern Quebec to examine the size, location, and habitat composition of their home ranges in areas where clear-cutting and precommercial thinning occurred. Home ranges of Bicknell's Thrush comprised more dense balsam fir stands and fewer thinned stands than available. Within home ranges, thrushes were found more frequently in unthinned balsam fir stands than in thinned stands, and they did not avoid edges. In fact, they were found disproportionately near edges of recently thinned stands. We conclude that Bicknell's Thrushes may coexist with forest management practices that maintain a landscape mosaic dominated by dense balsam fir patches interspersed with thinned stands.