: mid-May to early Jun and again late Aug-late Sep with from early May and to mid Oct. More numerous, sometimes dramatically so, in years of spruce budworm outbreaks in eastern Canada and the Maritimes.
Miscellany: Bay-breast bred here, abundantly during major spruce budworm infestations, until the mid 1990. There have been no confirmed records since then but isolated pairs may still breed.
It's remarkable how quickly Bar-breasted populations increase during a big budworm infestation. In the 1970s and 1980s, Barbara Patterson's Aug/Sep Somesville banding totals reflected the increase. In 1971, a pre-outbreak year, 25 were captured. At the height of the outbreak in 1979, and with more-or-less the same effort, 116 were caught.
Last Updated: March 18th, 2022