The best available long-term monitoring data for the Northern Mockingbird come from the Breeding Bird Survey (BBS), the results of which suggest little overall change in the population since the early 1970s. However, the estimated trend for Canada relies in part on the species' range-wide trend (i.e., the average trend across the BBS survey area, including in the United States) since there are relatively few observations of the species in any one region. Results vary quite a bit among the various provincial breeding bird atlas projects that record the species. Breeding evidence maps in the Maritimes Atlas indicate that the Northern Mockingbird was recorded in fewer atlas squares during the second atlas than previously (Horn 2015). The Atlas of the Breeding Birds of Quebec 2017 shows little change in the number of atlas squares in which the species was detected between the two Quebec atlases. The Atlas of the Breeding Birds of Ontario shows that the number of squares with breeding evidence for the species doubled between the two Atlas periods (Smith and Poon 2007). However, these results are now dated (i.e. the last Ontario Atlas wrapped up in 2005). Therefore, based on BBS results, the Northern Mockingbird population in Canada is thought to have experienced little overall change since 1970 and is within acceptable levels of its population goal (see Canada graph below). BBS results for North America also indicate little overall change in the continental population.
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
