North American bird populations are declining. A recent analysis of bird population trends across the U.S. and Canada suggests that we have lost 30% of our overall bird numbers since 1970, a reduction of nearly 3 billion individual birds.h Declines of par- ticular species are driven by diverse threats, but many of them are or will be exacer- bated by human-caused climate change. And climate change is expected to accelerate in the coming years, with its negative e ects on bird populations likely increasing in tandem.