The barn swallow is one of the world's most widely and common bird species. Yet for decades now, swallows are declining at an alarming rate. And Canada is no exception. Canadian Breeding Bird Survey data has shown that in the last 20 years, the population of barn swallows has fallen by 70 percent. In 2011, the Committee on the Status of Endangered Wildlife in Canada assessed the barn swallow as Threatened. In this program, videographers Mike McKinlay and Isabelle Groc check out barn swallow nests with Derek Matthews, master bander at the Vancouver Avian Research Centre, a non-profit organization he founded to monitor bird populations in the Lower Mainland region.