Breeding Bird Survey

To date, 28 species have been confirmed as breeding within the consus area. This considerable highter than the average breeding bird diversity for other confiferous forest sites at temmperate latitudes. It is likely that both the varied habitat and structural complexity of plant cover within the Catamount census area are responsible for the high bird species diversity reported here. However, one resource in particular - an abundance of mature aspen trees - contributes significantly to the availability of nest sites within the study area. All but two of the cavity-nesting pairs observed to date occupied holes in living aspen trees (both vireo pairs also nested in aspen). One 0.4-hectare aspen stand typically harbors 10-12 active nests, extrapolating to a record density of 27 breeding pairs per hectare. While the potential importance of dead tree snags to wildlife has long been recognized by forest managers, our survey shows that living aspen trees may far outnumber all other tree species - living or dead - in contributing to the breeding success of hole-nesting birds.