Sufficient monitoring data are not yet available to assess the Canadian population trend for this non-breeding pelagic visitor relative to 1970. Standardized ship-board surveys conducted in the 1970s indicate that Wilson’s Storm-Petrels are common and locally abundant along Georges and Browns Banks and the Nova Scotian Shelf from April to August, with some birds spreading upward to the northern Grand Bank and Labrador Coast through July. They begin a return migration to the Southern hemisphere by September (Brown 1986, Howell 2012). Stable isotope ratio studies suggest that these birds may be mainly pre-breeding age, while adult breeding birds remain mostly in the South Atlantic during the non-breeding period (Quillfeldt et al. 2005). The global breeding population of Wilson’s Storm-Petrel is estimated somewhere between 12,000,000 and 30,000,000 individuals (Brooke 2004) and, in the absence of evidence for any declines or substantial threats, the population is thought to be relatively stable (BirdLife International 2012a). Because of the lack of information specific to Canada, a national population goal for the Wilson's Storm-Petrel has not yet been determined.
