The Breeding Bird Survey (BBS) is the most reliable survey for monitoring the Grasshopper Sparrow in Canada, the results of which indicate little overall change in the national population relative to 1970. The national trend is driven mainly by trends in the two regions that host the highest densities of the species in Canada, the Prairie Potholes and the Great Lakes / St. Lawrence Plain Bird Conservation Regions (BCRs; all BCRs with reasonably reliable results are displayed below). While the trend in the Prairie Potholes is positive, the wide variation demonstrated in the annual index graph (see graph below) suggests there is little difference between the early 1970s and 2016. The trajectory of the population index in the Prairie Potholes generally reflects the pattern seen at the national level. The Grasshopper Sparrow, which includes all subspecies except the pratensis subspecies, is currentlyat an acceptable level relative to its national population goal, though it dipped below the lower level in the early 2000s (see Canada graph below). BBS results from throughout North America indicate a 70% decrease in the continental population. Though short-term results are not highly reliable, the annual indices for both the national and continental populations suggest that status has improved in recent years.
In contrast to the national population, the population in the Great Lakes / St. Lawrence Plain, which hosts the pratensis subspecies (Eastern Grasshopper Sparrow), has decreased steadily since 1970 and is below the lowest acceptable level relative to its national population goal (see BBS Great Lakes / St. Lawrence Plain graph below). This goal will be re-examined once the Management Plan for the subspecies is developed under the Species at Risk Act.
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
