Since…well, no one remembers exactly how long…the chimney atop the MSJ Powerhouse next door to our offices has hosted a flock of chimney swifts. We last saw these migrating birds last October when they left for South America for the winter. We noticed a few “scouts” during the last two of weeks of April, but it appears the main flock has now returned. Watching the swifts circle and fall one-by-one into the chimney at dusk is a favorite evening activity around here, one which we hope you experience at least once. While home chimneys may serve as small roosts, most communal roosts are large industrial chimneys which, as they fall into disuse and disrepair, are demolished, leaving fewer and fewer nest sites. The North American Breeding Bird Survey has noted a population decline of more than 70 percent since the mid-1960s, and declines of more than two percent each year continue. Specially-designed chimney swift towers can, however, replace these birds’ preferred habitat.