Regional patterns of habitat use by a threatened forest bird, the Bicknell's Thrush (Catharus bicknelli), in Quebec

摘要

Conservation of threatened species often uses habitat models to inform management of habitat and populations. We examined habitat use by Bicknell's Thrush [Catharus bicknelli (Ridgway, 1882)), a federally "Threatened" species, in two Appalachian regions, shaped by forestry activities, of southern Quebec. Within its breeding range, the species inhabits mountain tops and forests subjected to various logging activities. We assessed the role of vegetation and topography at two spatial scales, as well asspatial relationships with Swainson's Thrush (Catharus ustulatus (Nuttall, 1840)), identified as a potential competitor by some authors. In both regions, Bicknell's Thrushes were most likely to be reported at high elevations, in forest stands with high tree stem densities that underwent little or no stem reduction from forestry activities. Swainson's Thrashes were present at all sites were Bicknell's Thrashes were reported. These results are consistent with findings from studies in northeastern parts ofits breeding range. We conclude that forest-stand thinning should be kept to a minimum throughout the high-elevation nesting habitat of Bicknell's Thrash.