The Christmas Bird Count (CBC) covers most of the Rusty Blackbird's winter range and is the most reliable source of data for overall population trends. Although the CBC analysis combines data from throughout North America, a large portion of the population breeds in Canada (over 85%), thus the results are a good reflection of the status in Canada. The CBC suggests a 53% decrease in the continental population since about 1970. This decrease is echoed in results from the Breeding Bird Survey (BBS), which suggest an ongoing large decrease, with an estimated 68% loss of abundance in Canada over the same time period. BBS coverage is poor over much of the boreal forest where the species' breeding population is concentrated, thus results mainly reflect the southern portions of the species' range. Considering results from both surveys, the Rusty Blackbird can be reliably assessed as having experienced a large and ongoing decrease in Canada relative to the early 1970s. The national goal is based on CBC results (see CBC graph below), and is consistent with the objectives in the Management Plan (Environment Canada 2015d), which are to halt the decline in the short-term and achieve a sustained increase in population over the long-term. The Rusty Blackbird population is below the lowest acceptable level relative to its national population goal (see CBC graph below)
Additional information on: Christmas Bird Count (CBC)
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
