Citing declines (in some areas) by as much as 76% in the past 40 years, COSWEIC recently decided to list the Barn Swallow as Threatened (see: http://www.cosewic.gc.ca/eng/sct7/sct7_3_17_e.cfm).
Barn Swallow is one of several common insectivorous species experiencing declines and the cause is the subject of much debate. It remains unclear whether habitat change, insect distribution, abundance and phenology, or climate are at the root of these declines. Barn Swallow began declining in the mid 1980s; however, their present population is still generally considered to be higher in Canada now than before Europeans altered the landscape so drastically. Furthermore, the sources of the data available to assess swallow declines reveal biases and needs to taken with a large grain of salt. It will be interesting to watch the reaction to this listing both in Canada and in the international scientific community. This and several other recent COSEWIC decisions; for example, the recent listing of Bobolink and other species where COSEWIC's assessment differed radically from Birdlife International despite relying on largely the same data sets, have the potential to result in a tarnishing of our reputation… or perhaps provoking a wider discussion on what it means to call a species "Threatened"!