A trap to measure Populus and Salix seedfall

previous northern limit in British Columbia.This breeding expansion is appreciable but not unexpected in view of the highway and rail-line developments in this originally forested area.It seems likely that the modified habitats along these rights-of-way provided dispersal routes for Brewer's Blackbird.This species has been observed penetrating forested areas along cleared rights-of-way in areas of Alberta (Smith 1975), Saskatchewan and British Columbia (A.J. Erskine, personal communication).I acknowledge the assistance of Renewable Resources Consulting Services Ltd., with whom I was employed at the time of these observations.