Recent declines of House Sparrows, Passer domesticus, in Canada's Maritime Provinces

House Sparrows, Passer domesticus, were introduced to North America after 1850, increased and spread up to 1920, and stabilized or decreased thereafter until 1960. In the Maritimes (and perhaps some other areas), a further decline set in after 1970, continuing to the present. Now the species is rare to absent in much of the Maritimes, except around farms with livestock. Decline here since 1970 probably approaches 90 per cent in most other areas of human settlement except south of 45 degrees N. Similar declines are known in the U.K., but seem poorly documented, if recognized, in North America outside of our region.