I imagine lots of folks have seen the recent Leroy et al. study in Science, covered in the New York Times and elsewhere, but if you haven’t yet, it’s some very interesting food for thought!
It’s certainly a little different in scope and methodology from the recent State of Canada’s Birds, but there are some points of seeming overlap, in particular the correlation of accelerating declines with agricultural intensity (anecdotally tracking with severe declines in Canada’s grassland birds). The study also suggests high rates of decline in the hottest parts of the American south, something obviously not covered by the State of Canada’s Birds, and draws a correlation between declines and places with changing temperatures.
It’s also awesome to see yet another major and meaningful study based on volunteer-collected data (in this case the BBS) - some great encouragement for anyone you know who participates!